www.linuxsampler.org/api/draft-linuxsampler-protocol.txt



LinuxSampler Developers                              C. Schoenebeck, Ed.
Internet-Draft                                          LinuxSampler.org
Intended status: Informational                            March 11, 2019
Expires: September 12, 2019


                     LinuxSampler Control Protocol
                                LSCP 1.7

Abstract

   The LinuxSampler Control Protocol (LSCP) is an application-level
   protocol primarily intended for local and remote controlling the
   LinuxSampler backend application, which is a sophisticated server-
   like console application essentially playing back audio samples and
   manipulating the samples in real time to certain extent.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on September 12, 2019.

Copyright Notice

   Copyright (c) 2019 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.


Schoenebeck            Expires September 12, 2019               [Page 1]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   This document may not be modified, and derivative works of it may not
   be created, and it may not be published except as an Internet-Draft.

Table of Contents

   1.  Requirements notation . . . . . . . . . . . . . . . . . . . .   6
   2.  Versioning of this specification  . . . . . . . . . . . . . .   7
   3.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   8
   4.  Focus of this protocol  . . . . . . . . . . . . . . . . . . .   8
   5.  Communication Overview  . . . . . . . . . . . . . . . . . . .   8
     5.1.  Request/response communication method . . . . . . . . . .   9
       5.1.1.  Result format . . . . . . . . . . . . . . . . . . . .   9
     5.2.  Subscribe/notify communication method . . . . . . . . . .  12
   6.  Description for control commands  . . . . . . . . . . . . . .  13
     6.1.  Ignored lines and comments  . . . . . . . . . . . . . . .  14
     6.2.  Configuring audio drivers . . . . . . . . . . . . . . . .  14
       6.2.1.  Getting amount of available audio output drivers  . .  14
       6.2.2.  Getting all available audio output drivers  . . . . .  15
       6.2.3.  Getting information about a specific audio
               output driver . . . . . . . . . . . . . . . . . . . .  15
       6.2.4.  Getting information about specific audio
               output driver parameter . . . . . . . . . . . . . . .  16
       6.2.5.  Creating an audio output device . . . . . . . . . . .  20
       6.2.6.  Destroying an audio output device . . . . . . . . . .  21
       6.2.7.  Getting all created audio output device count . . . .  21
       6.2.8.  Getting all created audio output device list  . . . .  22
       6.2.9.  Getting current settings of an audio output device  .  22
       6.2.10. Changing settings of audio output devices . . . . . .  23
       6.2.11. Getting information about an audio channel  . . . . .  24
       6.2.12. Getting information about specific audio channel
               parameter . . . . . . . . . . . . . . . . . . . . . .  26
       6.2.13. Changing settings of audio output channels  . . . . .  28
     6.3.  Configuring MIDI input drivers  . . . . . . . . . . . . .  29
       6.3.1.  Getting amount of available MIDI input drivers  . . .  29
       6.3.2.  Getting all available MIDI input drivers  . . . . . .  30
       6.3.3.  Getting information about a specific MIDI input
               driver  . . . . . . . . . . . . . . . . . . . . . . .  30
       6.3.4.  Getting information about specific MIDI input driver
               parameter . . . . . . . . . . . . . . . . . . . . . .  31
       6.3.5.  Creating a MIDI input device  . . . . . . . . . . . .  34
       6.3.6.  Destroying a MIDI input device  . . . . . . . . . . .  35
       6.3.7.  Getting all created MIDI input device count . . . . .  35
       6.3.8.  Getting all created MIDI input device list  . . . . .  36
       6.3.9.  Getting current settings of a MIDI input device . . .  36
       6.3.10. Changing settings of MIDI input devices . . . . . . .  37
       6.3.11. Getting information about a MIDI port . . . . . . . .  38
       6.3.12. Getting information about specific MIDI port
               parameter . . . . . . . . . . . . . . . . . . . . . .  39


Schoenebeck            Expires September 12, 2019               [Page 2]

Internet-Draft        LinuxSampler Control Protocol           March 2019


       6.3.13. Changing settings of MIDI input ports . . . . . . . .  41
     6.4.  Configuring sampler channels  . . . . . . . . . . . . . .  41
       6.4.1.  Loading an instrument . . . . . . . . . . . . . . . .  42
       6.4.2.  Loading a sampler engine  . . . . . . . . . . . . . .  43
       6.4.3.  Getting all created sampler channel count . . . . . .  44
       6.4.4.  Getting all created sampler channel list  . . . . . .  44
       6.4.5.  Adding a new sampler channel  . . . . . . . . . . . .  44
       6.4.6.  Removing a sampler channel  . . . . . . . . . . . . .  45
       6.4.7.  Getting amount of available engines . . . . . . . . .  46
       6.4.8.  Getting all available engines . . . . . . . . . . . .  46
       6.4.9.  Getting information about an engine . . . . . . . . .  47
       6.4.10. Getting sampler channel information . . . . . . . . .  48
       6.4.11. Current number of active voices . . . . . . . . . . .  52
       6.4.12. Current number of active disk streams . . . . . . . .  52
       6.4.13. Current fill state of disk stream buffers . . . . . .  52
       6.4.14. Setting audio output device . . . . . . . . . . . . .  53
       6.4.15. Setting audio output type . . . . . . . . . . . . . .  54
       6.4.16. Setting audio output channel  . . . . . . . . . . . .  55
       6.4.17. Add MIDI input to sampler channel . . . . . . . . . .  56
       6.4.18. Remove MIDI input(s) from sampler channel . . . . . .  57
       6.4.19. Getting all MIDI inputs of a sampler channel  . . . .  58
       6.4.20. Setting MIDI input device . . . . . . . . . . . . . .  59
       6.4.21. Setting MIDI input type . . . . . . . . . . . . . . .  60
       6.4.22. Setting MIDI input port . . . . . . . . . . . . . . .  61
       6.4.23. Setting MIDI input channel  . . . . . . . . . . . . .  62
       6.4.24. Setting channel volume  . . . . . . . . . . . . . . .  63
       6.4.25. Muting a sampler channel  . . . . . . . . . . . . . .  63
       6.4.26. Soloing a sampler channel . . . . . . . . . . . . . .  64
       6.4.27. Assigning a MIDI instrument map to a sampler channel   65
       6.4.28. Adding an effect send to a sampler channel  . . . . .  66
       6.4.29. Removing an effect send from a sampler channel  . . .  67
       6.4.30. Getting amount of effect sends on a sampler channel .  68
       6.4.31. Listing all effect sends on a sampler channel . . . .  68
       6.4.32. Getting effect send information . . . . . . . . . . .  69
       6.4.33. Changing effect send's name . . . . . . . . . . . . .  71
       6.4.34. Altering effect send's audio routing  . . . . . . . .  71
       6.4.35. Assigning destination effect to an effect send  . . .  73
       6.4.36. Removing destination effect from an effect send . . .  74
       6.4.37. Altering effect send's MIDI controller  . . . . . . .  74
       6.4.38. Altering effect send's send level . . . . . . . . . .  75
       6.4.39. Sending MIDI messages to sampler channel  . . . . . .  76
       6.4.40. Resetting a sampler channel . . . . . . . . . . . . .  77
     6.5.  Controlling connection  . . . . . . . . . . . . . . . . .  78
       6.5.1.  Register front-end for receiving event messages . . .  78
       6.5.2.  Unregister front-end for not receiving event messages  78
       6.5.3.  Enable or disable echo of commands  . . . . . . . . .  79
       6.5.4.  Close client connection . . . . . . . . . . . . . . .  80
     6.6.  Global commands . . . . . . . . . . . . . . . . . . . . .  80


Schoenebeck            Expires September 12, 2019               [Page 3]

Internet-Draft        LinuxSampler Control Protocol           March 2019


       6.6.1.  Current number of active voices . . . . . . . . . . .  80
       6.6.2.  Maximum amount of active voices . . . . . . . . . . .  80
       6.6.3.  Current number of active disk streams . . . . . . . .  80
       6.6.4.  Reset sampler . . . . . . . . . . . . . . . . . . . .  81
       6.6.5.  General sampler information . . . . . . . . . . . . .  81
       6.6.6.  Getting global volume attenuation . . . . . . . . . .  82
       6.6.7.  Setting global volume attenuation . . . . . . . . . .  83
       6.6.8.  Getting global voice limit  . . . . . . . . . . . . .  83
       6.6.9.  Setting global voice limit  . . . . . . . . . . . . .  84
       6.6.10. Getting global disk stream limit  . . . . . . . . . .  84
       6.6.11. Setting global disk stream limit  . . . . . . . . . .  85
     6.7.  MIDI Instrument Mapping . . . . . . . . . . . . . . . . .  85
       6.7.1.  Create a new MIDI instrument map  . . . . . . . . . .  86
       6.7.2.  Delete one particular or all MIDI instrument maps . .  87
       6.7.3.  Get amount of existing MIDI instrument maps . . . . .  88
       6.7.4.  Getting all created MIDI instrument maps  . . . . . .  88
       6.7.5.  Getting MIDI instrument map information . . . . . . .  88
       6.7.6.  Renaming a MIDI instrument map  . . . . . . . . . . .  89
       6.7.7.  Create or replace a MIDI instrument map entry . . . .  90
       6.7.8.  Getting amount of MIDI instrument map entries . . . .  93
       6.7.9.  Getting indeces of all entries of a MIDI instrument
               map . . . . . . . . . . . . . . . . . . . . . . . . .  93
       6.7.10. Remove an entry from the MIDI instrument map  . . . .  94
       6.7.11. Get current settings of MIDI instrument map entry . .  95
       6.7.12. Clear MIDI instrument map . . . . . . . . . . . . . .  96
     6.8.  Managing Instruments Database . . . . . . . . . . . . . .  97
       6.8.1.  Creating a new instrument directory . . . . . . . . .  97
       6.8.2.  Deleting an instrument directory  . . . . . . . . . .  98
       6.8.3.  Getting amount of instrument directories  . . . . . .  99
       6.8.4.  Listing all directories in specific directory . . . .  99
       6.8.5.  Getting instrument directory information  . . . . . . 100
       6.8.6.  Renaming an instrument directory  . . . . . . . . . . 101
       6.8.7.  Moving an instrument directory  . . . . . . . . . . . 101
       6.8.8.  Copying instrument directories  . . . . . . . . . . . 102
       6.8.9.  Changing the description of directory . . . . . . . . 103
       6.8.10. Finding directories . . . . . . . . . . . . . . . . . 103
       6.8.11. Adding instruments to the instruments database  . . . 104
       6.8.12. Removing an instrument  . . . . . . . . . . . . . . . 106
       6.8.13. Getting amount of instruments . . . . . . . . . . . . 106
       6.8.14. Listing all instruments in specific directory . . . . 107
       6.8.15. Getting instrument information  . . . . . . . . . . . 107
       6.8.16. Renaming an instrument  . . . . . . . . . . . . . . . 110
       6.8.17. Moving an instrument  . . . . . . . . . . . . . . . . 110
       6.8.18. Copying instruments . . . . . . . . . . . . . . . . . 111
       6.8.19. Changing the description of instrument  . . . . . . . 112
       6.8.20. Finding instruments . . . . . . . . . . . . . . . . . 112
       6.8.21. Getting job status information  . . . . . . . . . . . 113
       6.8.22. Formatting the instruments database . . . . . . . . . 114


Schoenebeck            Expires September 12, 2019               [Page 4]

Internet-Draft        LinuxSampler Control Protocol           March 2019


       6.8.23. Checking for lost instrument files  . . . . . . . . . 115
       6.8.24. Replacing an instrument file  . . . . . . . . . . . . 115
     6.9.  Editing Instruments . . . . . . . . . . . . . . . . . . . 116
       6.9.1.  Opening an appropriate instrument editor application  116
     6.10. Managing Files  . . . . . . . . . . . . . . . . . . . . . 117
       6.10.1.  Retrieving amount of instruments of a file . . . . . 117
       6.10.2.  Retrieving all instruments of a file . . . . . . . . 118
       6.10.3.  Retrieving information about one instrument in a
                file . . . . . . . . . . . . . . . . . . . . . . . . 118
     6.11. Managing Effects  . . . . . . . . . . . . . . . . . . . . 120
       6.11.1.  Retrieve amount of available effects . . . . . . . . 121
       6.11.2.  Get list of available effects  . . . . . . . . . . . 121
       6.11.3.  Retrieving general information about an effect . . . 122
       6.11.4.  Creating an instance of an effect by its portable ID 123
       6.11.5.  Creating an instance of an effect by its numerical
                ID . . . . . . . . . . . . . . . . . . . . . . . . . 124
       6.11.6.  Destroy an effect instance . . . . . . . . . . . . . 125
       6.11.7.  Retrieve amount of effect instances  . . . . . . . . 126
       6.11.8.  Get list of effect instances . . . . . . . . . . . . 126
       6.11.9.  Retrieving current information about an effect
                instance . . . . . . . . . . . . . . . . . . . . . . 126
       6.11.10. Retrieving information about an effect parameter . . 128
       6.11.11. Altering an effect parameter . . . . . . . . . . . . 130
       6.11.12. Retrieve amount of send effect chains  . . . . . . . 130
       6.11.13. Retrieve list of send effect chains  . . . . . . . . 131
       6.11.14. Add send effect chain  . . . . . . . . . . . . . . . 131
       6.11.15. Remove send effect chain . . . . . . . . . . . . . . 132
       6.11.16. Retrieving information about a send effect chain . . 132
       6.11.17. Append effect instance to a send effect chain  . . . 133
       6.11.18. Insert effect instance to a send effect chain  . . . 134
       6.11.19. Remove effect instance from send effect chain  . . . 135
   7.  Command Syntax  . . . . . . . . . . . . . . . . . . . . . . . 136
     7.1.  Character Set and Escape Sequences  . . . . . . . . . . . 153
   8.  Events  . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
     8.1.  Number of audio output devices changed  . . . . . . . . . 157
     8.2.  Audio output device's settings changed  . . . . . . . . . 157
     8.3.  Number of MIDI input devices changed  . . . . . . . . . . 157
     8.4.  MIDI input device's settings changed  . . . . . . . . . . 158
     8.5.  Number of sampler channels changed  . . . . . . . . . . . 158
     8.6.  MIDI data on a sampler channel arrived  . . . . . . . . . 158
     8.7.  MIDI data on a MIDI input device arrived  . . . . . . . . 159
     8.8.  Number of active voices changed . . . . . . . . . . . . . 159
     8.9.  Number of active disk streams changed . . . . . . . . . . 160
     8.10. Disk stream buffer fill state changed . . . . . . . . . . 160
     8.11. Channel information changed . . . . . . . . . . . . . . . 160
     8.12. Number of effect sends changed  . . . . . . . . . . . . . 161
     8.13. Effect send information changed . . . . . . . . . . . . . 161
     8.14. Total number of active voices changed . . . . . . . . . . 162


Schoenebeck            Expires September 12, 2019               [Page 5]

Internet-Draft        LinuxSampler Control Protocol           March 2019


     8.15. Total number of active disk streams changed . . . . . . . 162
     8.16. Number of MIDI instrument maps changed  . . . . . . . . . 162
     8.17. MIDI instrument map information changed . . . . . . . . . 162
     8.18. Number of MIDI instruments changed  . . . . . . . . . . . 163
     8.19. MIDI instrument information changed . . . . . . . . . . . 163
     8.20. Global settings changed . . . . . . . . . . . . . . . . . 164
     8.21. Number of database instrument directories changed . . . . 164
     8.22. Database instrument directory information changed . . . . 165
     8.23. Number of database instruments changed  . . . . . . . . . 165
     8.24. Database instrument information changed . . . . . . . . . 166
     8.25. Database job status information changed . . . . . . . . . 166
     8.26. Number of effect instances changed  . . . . . . . . . . . 167
     8.27. Effect instance information changed . . . . . . . . . . . 167
     8.28. Number of send effect chains changed  . . . . . . . . . . 167
     8.29. Send effect chain information changed . . . . . . . . . . 168
     8.30. Miscellaneous and debugging events  . . . . . . . . . . . 168
   9.  Security Considerations . . . . . . . . . . . . . . . . . . . 168
   10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 168
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . . 169
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . 169

1.  Requirements notation

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

   This protocol is always case-sensitive if not explicitly claimed the
   opposite.

   In examples, "C:" and "S:" indicate lines sent by the client (front-
   end) and server (LinuxSampler) respectively.  Lines in examples must
   be interpreted as every line being CRLF terminated (carriage return
   character followed by line feed character as defined in the ASCII
   standard [RFC20]), thus the following example:

      C: "some line"

      "another line"

   must actually be interpreted as client sending the following message:

      "some line<CR><LF>another line<CR><LF>"

   where <CR> symbolizes the carriage return character and <LF> the line
   feed character as defined in the ASCII standard.


Schoenebeck            Expires September 12, 2019               [Page 6]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Due to technical reasons, messages can arbitrary be fragmented, means
   the following example:

      S: "abcd"

   could also happen to be sent in three messages like in the following
   sequence scenario:

   o  server sending message "a"

   o  followed by a delay (pause) with arbitrary duration

   o  followed by server sending message "bcd<CR>"

   o  again followed by a delay (pause) with arbitrary duration

   o  followed by server sending the message "<LF>"

   where again <CR> and <LF> symbolize the carriage return and line feed
   characters respectively.

2.  Versioning of this specification

   LSCP will certainly be extended and enhanced by-and-by.  Each
   official release of the LSCP specification will be tagged with a
   unique version tuple.  The version tuple consists at least of a major
   and minor version number like:

      "1.2"

   In this example the major version number would be "1" and the minor
   version number would be "2".  Note that the version tuple might also
   have more than two elements.  The major version number defines a
   group of backward compatible versions.  That means a frontend is
   compatible to the connected sampler if and only if the LSCP versions
   to which each of the two parties complies to, match both of the
   following rules:

   Compatibility:

   1.  The frontend's LSCP major version and the sampler's LSCP major
       version are exactly equal.

   2.  The frontend's LSCP minor version is less or equal than the
       sampler's LSCP minor version.


Schoenebeck            Expires September 12, 2019               [Page 7]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Compatibility can only be claimed if both rules are true.  The
   frontend can use the "GET SERVER INFO" (Section 6.6.5) command to get
   the version of the LSCP specification the sampler complies with.

3.  Introduction

   LinuxSampler is a so called software sampler application capable to
   playback audio samples from a computer's Random Access Memory (RAM)
   as well as directly streaming it from disk.  LinuxSampler is designed
   to be modular.  It provides several so called "sampler engines" where
   each engine is specialized for a certain purpose.  LinuxSampler has
   virtual channels which will be referred in this document as "sampler
   channels".  The channels are in such way virtual as they can be
   connected to an arbitrary MIDI input method and arbitrary MIDI
   channel (e.g.  sampler channel 17 could be connected to an ALSA
   sequencer device 64:0 and listening to MIDI channel 1 there).  Each
   sampler channel will be associated with an instance of one of the
   available sampler engines (e.g.  GigEngine, DLSEngine).  The audio
   output of each sampler channel can be routed to an arbitrary audio
   output method (ALSA / JACK) and an arbitrary audio output channel
   there.

4.  Focus of this protocol

   Main focus of this protocol is to provide a way to configure a
   running LinuxSampler instance and to retrieve information about it.
   The focus of this protocol is not to provide a way to control
   synthesis parameters or even to trigger or release notes.  Or in
   other words; the focus are those functionalities which are not
   covered by MIDI or which may at most be handled via MIDI System
   Exclusive Messages.

5.  Communication Overview

   There are two distinct methods of communication between a running
   instance of LinuxSampler and one or more control applications, so
   called "front-ends": a simple request/response communication method
   used by the clients to give commands to the server as well as to
   inquire about server's status and a subscribe/notify communication
   method used by the client to subscribe to and receive notifications
   of certain events as they happen on the server.  The latter needs
   more effort to be implemented in the front-end application.  The two
   communication methods will be described next.


Schoenebeck            Expires September 12, 2019               [Page 8]

Internet-Draft        LinuxSampler Control Protocol           March 2019


5.1.  Request/response communication method

   This simple communication method is based on TCP [RFC793].  The
   front-end application establishes a TCP connection to the
   LinuxSampler instance on a certain host system.  Then the front-end
   application will send certain ASCII based commands as defined in this
   document (every command line must be CRLF terminated - see
   "Conventions used in this document" at the beginning of this
   document) and the LinuxSampler application will response after a
   certain process time with an appropriate ASCII based answer, also as
   defined in this document.  So this TCP communication is simply based
   on query and answer paradigm.  That way LinuxSampler is only able to
   answer on queries from front-ends, but not able to automatically send
   messages to the client if it's not asked to.  The fronted should not
   reconnect to LinuxSampler for every single command, instead it should
   keep the connection established and simply resend message(s) for
   subsequent commands.  To keep information in the front-end up-to-date
   the front-end has to periodically send new requests to get the
   current information from the LinuxSampler instance.  This is often
   referred to as "polling".  While polling is simple to implement and
   may be OK to use in some cases, there may be disadvantages to polling
   such as network traffic overhead and information being out of date.
   It is possible for a client or several clients to open more than one
   connection to the server at the same time.  It is also possible to
   send more than one request to the server at the same time but if
   those requests are sent over the same connection server MUST execute
   them sequentially.  Upon executing a request server will produce a
   result set and send it to the client.  Each and every request made by
   the client MUST result in a result set being sent back to the client.
   No other data other than a result set may be sent by a server to a
   client.  No result set may be sent to a client without the client
   sending request to the server first.  On any particular connection,
   result sets MUST be sent in their entirety without being interrupted
   by other result sets.  If several requests got queued up at the
   server they MUST be processed in the order they were received and
   result sets MUST be sent back in the same order.

5.1.1.  Result format

   Result set could be one of the following types:

   1.  Normal

   2.  Warning

   3.  Error


Schoenebeck            Expires September 12, 2019               [Page 9]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Warning and Error result sets MUST be single line and have the
   following format:

   o  "WRN:<warning-code>:<warning-message>"

   o  "ERR:<error-code>:<error-message>"

   Where <warning-code> and <error-code> are numeric unique identifiers
   of the warning or error and <warning-message> and <error-message> are
   human readable descriptions of the warning or error respectively.

   Examples:

      C: "LOAD INSTRUMENT '/home/me/Boesendorfer24bit.gig" 0 0

      S: "WRN:32:This is a 24 bit patch which is not supported natively
      yet."

      C: "GET AUDIO_OUTPUT_DRIVER_PARAMETER INFO ALSA EAR"

      S: "ERR:3456:Audio output driver 'ALSA' does not have a parameter
      'EAR'."

      C: "GET AUDIO_OUTPUT_DEVICE INFO 123456"

      S: "ERR:9:There is no audio output device with index 123456."

   Normal result sets could be:

   1.  Empty

   2.  Single line

   3.  Multi-line

   Empty result set is issued when the server only needed to acknowledge
   the fact that the request was received and it was processed
   successfully and no additional information is available.  This result
   set has the following format:

      "OK"

   Example:

      C: "SET AUDIO_OUTPUT_DEVICE_PARAMETER 0 CHANNELS=4"

      S: "OK"


Schoenebeck            Expires September 12, 2019              [Page 10]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Single line result sets are command specific.  One example of a
   single line result set is an empty line.  Multi-line result sets are
   command specific and may include one or more lines of information.
   They MUST always end with the following line:

      "."

   Example:

      C: "GET AUDIO_OUTPUT_DEVICE INFO 0"

      S: "DRIVER: ALSA"

      "CHANNELS: 2"

      "SAMPLERATE: 44100"

      "ACTIVE: true"

      "FRAGMENTS: 2"

      "FRAGMENTSIZE: 128"

      "CARD: '0,0'"

      "."

   In addition to above mentioned formats, warnings and empty result
   sets MAY be indexed.  In this case, they have the following formats
   respectively:

   o  "WRN[<index>]:<warning-code>:<warning-message>"

   o  "OK[<index>]"

   where <index> is command specific and is used to indicate channel
   number that the result set was related to or other integer value.

   Each line of the result set MUST end with <CRLF>.

   Examples:

      C: "ADD CHANNEL"

      S: "OK[12]"

      C: "CREATE AUDIO_OUTPUT_DEVICE ALSA SAMPLERATE=96000"


Schoenebeck            Expires September 12, 2019              [Page 11]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      S: "WRN[0]:32:Sample rate not supported, using 44100 instead."

5.2.  Subscribe/notify communication method

   This more sophisticated communication method is actually only an
   extension of the simple request/response communication method.  The
   front-end still uses a TCP connection and sends the same commands on
   the TCP connection.  Two extra commands are SUBSCRIBE and UNSUBSCRIBE
   commands that allow a client to tell the server that it is interested
   in receiving notifications about certain events as they happen on the
   server.  The SUBSCRIBE command has the following syntax:

      SUBSCRIBE <event-id>

   where <event-id> will be replaced by the respective event that client
   wants to subscribe to.  Upon receiving such request, server SHOULD
   respond with OK and start sending EVENT notifications when a given
   even has occurred to the front-end when an event has occurred.  It
   MAY be possible certain events may be sent before OK response during
   real time nature of their generation.  Event messages have the
   following format:

      NOTIFY:<event-id>:<custom-event-data>

   where <event-id> uniquely identifies the event that has occurred and
   <custom-event-data> is event specific.

   Several rules must be followed by the server when generating events:

   1.  Events MUST NOT be sent to any client who has not issued an
       appropriate SUBSCRIBE command.

   2.  Events MUST only be sent using the same connection that was used
       to subscribe to them.

   3.  When response is being sent to the client, event MUST be inserted
       in the stream before or after the response, but NOT in the
       middle.  Same is true about the response.  It should never be
       inserted in the middle of the event message as well as any other
       response.

   If the client is not interested in a particular event anymore it MAY
   issue UNSUBSCRIBE command using the following syntax:

      UNSUBSCRIBE <event-id>


Schoenebeck            Expires September 12, 2019              [Page 12]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   where <event-id> will be replace by the respective event that client
   is no longer interested in receiving.  For a list of supported events
   see Section 8.

   Example: the fill states of disk stream buffers have changed on
   sampler channel 4 and the LinuxSampler instance will react by sending
   the following message to all clients who subscribed to this event:

      NOTIFY:CHANNEL_BUFFER_FILL:4 [35]62%,[33]80%,[37]98%

   Which means there are currently three active streams on sampler
   channel 4, where the stream with ID "35" is filled by 62%, stream
   with ID 33 is filled by 80% and stream with ID 37 is filled by 98%.

   Clients may choose to open more than one connection to the server and
   use some connections to receive notifications while using other
   connections to issue commands to the back-end.  This is entirely
   legal and up to the implementation.  This does not change the
   protocol in any way and no special restrictions exist on the server
   to allow or disallow this or to track what connections belong to what
   front-ends.  Server will listen on a single port, accept multiple
   connections and support protocol described in this specification in
   it's entirety on this single port on each connection that it
   accepted.

   Due to the fact that TCP is used for this communication, dead peers
   will be detected automatically by the OS TCP stack.  While it may
   take a while to detect dead peers if no traffic is being sent from
   server to client (TCP keep-alive timer is set to 2 hours on many
   OSes) it will not be an issue here as when notifications are sent by
   the server, dead client will be detected quickly.

   When connection is closed for any reason server MUST forget all
   subscriptions that were made on this connection.  If client
   reconnects it MUST resubscribe to all events that it wants to
   receive.

6.  Description for control commands

   This chapter will describe the available control commands that can be
   sent on the TCP connection in detail.  Some certain commands (e.g.
   "GET CHANNEL INFO" (Section 6.4.10) or "GET ENGINE INFO"
   (Section 6.4.9)) lead to multiple-line responses.  In this case
   LinuxSampler signals the end of the response by a "." (single dot)
   line.


Schoenebeck            Expires September 12, 2019              [Page 13]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.1.  Ignored lines and comments

   White lines, that is lines which only contain space and tabulator
   characters, and lines that start with a "#" character are ignored,
   thus it's possible for example to group commands and to place
   comments in a LSCP script file.

6.2.  Configuring audio drivers

   Instances of drivers in LinuxSampler are called devices.  You can use
   multiple audio devices simultaneously, e.g. to output the sound of
   one sampler channel using the ALSA audio output driver, and on
   another sampler channel you might want to use the JACK audio output
   driver.  For particular audio output systems it's also possible to
   create several devices of the same audio output driver, e.g. two
   separate ALSA audio output devices for using two different sound
   cards at the same time.  This chapter describes all commands to
   configure LinuxSampler's audio output devices and their parameters.

   Instead of defining commands and parameters for each driver
   individually, all possible parameters, their meanings and possible
   values have to be obtained at runtime.  This makes the protocol a bit
   abstract, but has the advantage, that front-ends can be written
   independently of what drivers are currently implemented and what
   parameters these drivers are actually offering.  This means front-
   ends can even handle drivers which are implemented somewhere in
   future without modifying the front-end at all.

   Note: examples in this chapter showing particular parameters of
   drivers are not meant as specification of the drivers' parameters.
   Driver implementations in LinuxSampler might have complete different
   parameter names and meanings than shown in these examples or might
   change in future, so these examples are only meant for showing how to
   retrieve what parameters drivers are offering, how to retrieve their
   possible values, etc.

6.2.1.  Getting amount of available audio output drivers

   Use the following command to get the number of audio output drivers
   currently available for the LinuxSampler instance:

      GET AVAILABLE_AUDIO_OUTPUT_DRIVERS

   Possible Answers:

      LinuxSampler will answer by sending the number of audio output
      drivers.


Schoenebeck            Expires September 12, 2019              [Page 14]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Example:

      C: "GET AVAILABLE_AUDIO_OUTPUT_DRIVERS"

      S: "2"

6.2.2.  Getting all available audio output drivers

   Use the following command to list all audio output drivers currently
   available for the LinuxSampler instance:

      LIST AVAILABLE_AUDIO_OUTPUT_DRIVERS

   Possible Answers:

      LinuxSampler will answer by sending comma separated character
      strings, each symbolizing an audio output driver.

   Example:

      C: "LIST AVAILABLE_AUDIO_OUTPUT_DRIVERS"

      S: "ALSA,JACK"

6.2.3.  Getting information about a specific audio output driver

   Use the following command to get detailed information about a
   specific audio output driver:

      GET AUDIO_OUTPUT_DRIVER INFO <audio-output-driver>

   Where <audio-output-driver> is the name of the audio output driver,
   returned by the "LIST AVAILABLE_AUDIO_OUTPUT_DRIVERS" (Section 6.2.2)
   command.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that info category.  At the moment the
      following information categories are defined:


         DESCRIPTION -

            character string describing the audio output driver


Schoenebeck            Expires September 12, 2019              [Page 15]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         VERSION -

            character string reflecting the driver's version

         PARAMETERS -

            comma separated list of all parameters available for the
            given audio output driver, at least parameters 'channels',
            'samplerate' and 'active' are offered by all audio output
            drivers

      The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET AUDIO_OUTPUT_DRIVER INFO ALSA"

      S: "DESCRIPTION: Advanced Linux Sound Architecture"

      "VERSION: 1.0"

      "PARAMETERS: DRIVER,CHANNELS,SAMPLERATE,ACTIVE,FRAGMENTS,
      FRAGMENTSIZE,CARD"

      "."

6.2.4.  Getting information about specific audio output driver parameter

   Use the following command to get detailed information about a
   specific audio output driver parameter:

      GET AUDIO_OUTPUT_DRIVER_PARAMETER INFO <audio> <prm> [<deplist>]

   Where <audio> is the name of the audio output driver as returned by
   the "LIST AVAILABLE_AUDIO_OUTPUT_DRIVERS" (Section 6.2.2) command,
   <prm> a specific parameter name for which information should be
   obtained (as returned by the "GET AUDIO_OUTPUT_DRIVER INFO"
   (Section 6.2.3) command) and <deplist> is an optional list of
   parameters on which the sought parameter <prm> depends on, <deplist>
   is a list of key-value pairs in form of "key1=val1 key2=val2 ...",
   where character string values are encapsulated into apostrophes (').
   Arguments given with <deplist> which are not dependency parameters of
   <prm> will be ignored, means the front-end application can simply put
   all parameters into <deplist> with the values already selected by the
   user.

   Possible Answers:


Schoenebeck            Expires September 12, 2019              [Page 16]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that info category.  There are information
      which is always returned, independently of the given driver
      parameter and there are optional information which is only shown
      dependently to given driver parameter.  At the moment the
      following information categories are defined:

      TYPE -

         either "BOOL" for boolean value(s) or "INT" for integer
         value(s) or "FLOAT" for dotted number(s) or "STRING" for
         character string(s) (always returned, no matter which driver
         parameter)

      DESCRIPTION -

         arbitrary text describing the purpose of the parameter (always
         returned, no matter which driver parameter)

      MANDATORY -

         either true or false, defines if this parameter must be given
         when the device is to be created with the 'CREATE
         AUDIO_OUTPUT_DEVICE' (Section 6.2.5) command (always returned,
         no matter which driver parameter)

      FIX -

         either true or false, if false then this parameter can be
         changed at any time, once the device is created by the 'CREATE
         AUDIO_OUTPUT_DEVICE' (Section 6.2.5) command (always returned,
         no matter which driver parameter)

      MULTIPLICITY -

         either true or false, defines if this parameter allows only one
         value or a list of values, where true means multiple values and
         false only a single value allowed (always returned, no matter
         which driver parameter)

      DEPENDS -

         comma separated list of parameters this parameter depends on,
         means the values for fields 'DEFAULT', 'RANGE_MIN', 'RANGE_MAX'
         and 'POSSIBILITIES' might depend on these listed parameters,
         for example assuming that an audio driver (like the ALSA


Schoenebeck            Expires September 12, 2019              [Page 17]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         driver) offers parameters 'card' and 'samplerate' then
         parameter 'samplerate' would depend on 'card' because the
         possible values for 'samplerate' depends on the sound card
         which can be chosen by the 'card' parameter (optionally
         returned, dependent to driver parameter)

      DEFAULT -

         reflects the default value for this parameter which is used
         when the device is created and not explicitly given with the
         'CREATE AUDIO_OUTPUT_DEVICE' (Section 6.2.5) command, in case
         of MULTIPLCITY=true, this is a comma separated list, that's why
         character strings are encapsulated into apostrophes (')
         (optionally returned, dependent to driver parameter)

      RANGE_MIN -

         defines lower limit of the allowed value range for this
         parameter, can be an integer value as well as a dotted number,
         this parameter is often used in conjunction with RANGE_MAX, but
         may also appear without (optionally returned, dependent to
         driver parameter)

      RANGE_MAX -

         defines upper limit of the allowed value range for this
         parameter, can be an integer value as well as a dotted number,
         this parameter is often used in conjunction with RANGE_MIN, but
         may also appear without (optionally returned, dependent to
         driver parameter)

      POSSIBILITIES -

         comma separated list of possible values for this parameter,
         character strings are encapsulated into apostrophes (optionally
         returned, dependent to driver parameter)

   The mentioned fields above don't have to be in particular order.

   Examples:

      C: "GET AUDIO_OUTPUT_DRIVER_PARAMETER INFO ALSA CARD"

      S: "DESCRIPTION: sound card to be used"

      "TYPE: STRING"

      "MANDATORY: false"


Schoenebeck            Expires September 12, 2019              [Page 18]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "FIX: true"

      "MULTIPLICITY: false"

      "DEFAULT: '0,0'"

      "POSSIBILITIES: '0,0','1,0','2,0'"

      "."

      C: "GET AUDIO_OUTPUT_DRIVER_PARAMETER INFO ALSA SAMPLERATE"

      S: "DESCRIPTION: output sample rate in Hz"

      "TYPE: INT"

      "MANDATORY: false"

      "FIX: false"

      "MULTIPLICITY: false"

      "DEPENDS: card"

      "DEFAULT: 44100"

      "."

      C: "GET AUDIO_OUTPUT_DRIVER_PARAMETER INFO ALSA SAMPLERATE
      CARD='0,0'"

      S: "DESCRIPTION: output sample rate in Hz"

      "TYPE: INT"

      "MANDATORY: false"

      "FIX: false"

      "MULTIPLICITY: false"

      "DEPENDS: card"

      "DEFAULT: 44100"

      "RANGE_MIN: 22050"

      "RANGE_MAX: 96000"


Schoenebeck            Expires September 12, 2019              [Page 19]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "."

6.2.5.  Creating an audio output device

   Use the following command to create a new audio output device for the
   desired audio output system:

      CREATE AUDIO_OUTPUT_DEVICE <audio-output-driver> [<param-list>]

   Where <audio-output-driver> should be replaced by the desired audio
   output system as returned by the "LIST
   AVAILABLE_AUDIO_OUTPUT_DRIVERS" (Section 6.2.2) command and <param-
   list> by an optional list of driver specific parameters in form of
   "key1=val1 key2=val2 ...", where character string values should be
   encapsulated into apostrophes (').  Note that there might be drivers
   which require parameter(s) to be given with this command.  Use the
   previously described commands in this chapter to get this
   information.

   Possible Answers:

      "OK[<device-id>]" -

         in case the device was successfully created, where <device-id>
         is the numerical ID of the new device

      "WRN[<device-id>]:<warning-code>:<warning-message>" -

         in case the device was created successfully, where <device-id>
         is the numerical ID of the new device, but there are noteworthy
         issue(s) related (e.g. sound card doesn't support given
         hardware parameters and the driver is using fall-back values),
         providing an appropriate warning code and warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:

      C: "CREATE AUDIO_OUTPUT_DEVICE ALSA"

      S: "OK[0]"

      C: "CREATE AUDIO_OUTPUT_DEVICE ALSA CARD='2,0' SAMPLERATE=96000"

      S: "OK[1]"


Schoenebeck            Expires September 12, 2019              [Page 20]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.2.6.  Destroying an audio output device

   Use the following command to destroy a created output device:

      DESTROY AUDIO_OUTPUT_DEVICE <device-id>

   Where <device-id> should be replaced by the numerical ID of the audio
   output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command.

   Possible Answers:

      "OK" -

         in case the device was successfully destroyed

      "WRN:<warning-code>:<warning-message>" -

         in case the device was destroyed successfully, but there are
         noteworthy issue(s) related (e.g. an audio over ethernet driver
         was unloaded but the other host might not be informed about
         this situation), providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "DESTROY AUDIO_OUTPUT_DEVICE 0"

      S: "OK"

6.2.7.  Getting all created audio output device count

   Use the following command to count all created audio output devices:

      GET AUDIO_OUTPUT_DEVICES

   Possible Answers:

      LinuxSampler will answer by sending the current number of all
      audio output devices.

   Example:


Schoenebeck            Expires September 12, 2019              [Page 21]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      C: "GET AUDIO_OUTPUT_DEVICES"

      S: "4"

6.2.8.  Getting all created audio output device list

   Use the following command to list all created audio output devices:

      LIST AUDIO_OUTPUT_DEVICES

   Possible Answers:

      LinuxSampler will answer by sending a comma separated list with
      the numerical IDs of all audio output devices.

   Example:

      C: "LIST AUDIO_OUTPUT_DEVICES"

      S: "0,1,4,5"

6.2.9.  Getting current settings of an audio output device

   Use the following command to get current settings of a specific,
   created audio output device:

      GET AUDIO_OUTPUT_DEVICE INFO <device-id>

   Where <device-id> should be replaced by numerical ID of the audio
   output device as e.g. returned by the "LIST AUDIO_OUTPUT_DEVICES"
   (Section 6.2.8) command.

   Possible Answers:

   LinuxSampler will answer by sending a <CRLF> separated list.  Each
   answer line begins with the information category name followed by a
   colon and then a space character <SP> and finally the info character
   string to that info category.  As some parameters might allow
   multiple values, character strings are encapsulated into apostrophes
   (').  At the moment the following information categories are defined
   (independently of device):

      DRIVER -

         identifier of the used audio output driver, as also returned by
         the "LIST AVAILABLE_AUDIO_OUTPUT_DRIVERS" (Section 6.2.2)
         command


Schoenebeck            Expires September 12, 2019              [Page 22]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      CHANNELS -

         amount of audio output channels this device currently offers

      SAMPLERATE -

         playback sample rate the device uses

      ACTIVE -

         either true or false, if false then the audio device is
         inactive and doesn't output any sound, nor do the sampler
         channels connected to this audio device render any audio

   The mentioned fields above don't have to be in particular order.  The
   fields above are only those fields which are returned by all audio
   output devices.  Every audio output driver might have its own,
   additional driver specific parameters (see Section 6.2.3) which are
   also returned by this command.

   Example:

      C: "GET AUDIO_OUTPUT_DEVICE INFO 0"

      S: "DRIVER: ALSA"

      "CHANNELS: 2"

      "SAMPLERATE: 44100"

      "ACTIVE: true"

      "FRAGMENTS: 2"

      "FRAGMENTSIZE: 128"

      "CARD: '0,0'"

      "."

6.2.10.  Changing settings of audio output devices

   Use the following command to alter a specific setting of a created
   audio output device:

      SET AUDIO_OUTPUT_DEVICE_PARAMETER <device-id> <key>=<value>


Schoenebeck            Expires September 12, 2019              [Page 23]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Where <device-id> should be replaced by the numerical ID of the audio
   output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command, <key> by the name of the parameter to change and <value> by
   the new value for this parameter.

   Possible Answers:

      "OK" -

         in case setting was successfully changed

      "WRN:<warning-code>:<warning-message>" -

         in case setting was changed successfully, but there are
         noteworthy issue(s) related, providing an appropriate warning
         code and warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "SET AUDIO_OUTPUT_DEVICE_PARAMETER 0 FRAGMENTSIZE=128"

      S: "OK"

6.2.11.  Getting information about an audio channel

   Use the following command to get information about an audio channel:

      GET AUDIO_OUTPUT_CHANNEL INFO <device-id> <audio-chan>

   Where <device-id> is the numerical ID of the audio output device as
   given by the "CREATE AUDIO_OUTPUT_DEVICE" (Section 6.2.5) or "LIST
   AUDIO_OUTPUT_DEVICES" (Section 6.2.8) command and <audio-chan> the
   audio channel number.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that info category.  At the moment the
      following information categories are defined:


Schoenebeck            Expires September 12, 2019              [Page 24]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         NAME -

            arbitrary character string naming the channel, which doesn't
            have to be unique (always returned by all audio channels)

         IS_MIX_CHANNEL -

            either true or false, a mix-channel is not a real,
            independent audio channel, but a virtual channel which is
            mixed to another real channel, this mechanism is needed for
            sampler engines which need more audio channels than the used
            audio system might be able to offer (always returned by all
            audio channels)

         MIX_CHANNEL_DESTINATION -

            numerical ID (positive integer including 0) which reflects
            the real audio channel (of the same audio output device)
            this mix channel refers to, means where the audio signal
            actually will be routed / added to (only returned in case
            the audio channel is mix channel)

   The mentioned fields above don't have to be in particular order.  The
   fields above are only those fields which are generally returned for
   the described cases by all audio channels regardless of the audio
   driver.  Every audio channel might have its own, additional driver
   and channel specific parameters.

   Examples:

      C: "GET AUDIO_OUTPUT_CHANNEL INFO 0 0"

      S: "NAME: studio monitor left"

      "IS_MIX_CHANNEL: false"

      "."

      C: "GET AUDIO_OUTPUT_CHANNEL INFO 0 1"

      S: "NAME: studio monitor right"

      "IS_MIX_CHANNEL: false"

      "."

      C: "GET AUDIO_OUTPUT_CHANNEL INFO 0 2"


Schoenebeck            Expires September 12, 2019              [Page 25]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      S: "NAME: studio monitor left"

      "IS_MIX_CHANNEL: true"

      "MIX_CHANNEL_DESTINATION: 1"

      "."

      C: "GET AUDIO_OUTPUT_CHANNEL INFO 1 0"

      S: "NAME: 'ardour (left)'"

      "IS_MIX_CHANNEL: false"

      "JACK_BINDINGS: 'ardour:0'"

      "."

6.2.12.  Getting information about specific audio channel parameter

   Use the following command to get detailed information about specific
   audio channel parameter:

      GET AUDIO_OUTPUT_CHANNEL_PARAMETER INFO <dev-id> <chan> <param>

   Where <dev-id> is the numerical ID of the audio output device as
   returned by the "CREATE AUDIO_OUTPUT_DEVICE" (Section 6.2.5) or "LIST
   AUDIO_OUTPUT_DEVICES" (Section 6.2.8) command, <chan> the audio
   channel number and <param> a specific channel parameter name for
   which information should be obtained (as returned by the "GET
   AUDIO_OUTPUT_CHANNEL INFO" (Section 6.2.11) command).

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that info category.  There are information
      which is always returned, independently of the given channel
      parameter and there is optional information which is only shown
      dependently to the given audio channel.  At the moment the
      following information categories are defined:


         TYPE -


Schoenebeck            Expires September 12, 2019              [Page 26]

Internet-Draft        LinuxSampler Control Protocol           March 2019


            either "BOOL" for boolean value(s) or "INT" for integer
            value(s) or "FLOAT" for dotted number(s) or "STRING" for
            character string(s) (always returned)

         DESCRIPTION -

            arbitrary text describing the purpose of the parameter
            (always returned)

         FIX -

            either true or false, if true then this parameter is read
            only, thus cannot be altered (always returned)

         MULTIPLICITY -

            either true or false, defines if this parameter allows only
            one value or a list of values, where true means multiple
            values and false only a single value allowed (always
            returned)

         RANGE_MIN -

            defines lower limit of the allowed value range for this
            parameter, can be an integer value as well as a dotted
            number, usually used in conjunction with 'RANGE_MAX', but
            may also appear without (optionally returned, dependent to
            driver and channel parameter)

         RANGE_MAX -

            defines upper limit of the allowed value range for this
            parameter, can be an integer value as well as a dotted
            number, usually used in conjunction with 'RANGE_MIN', but
            may also appear without (optionally returned, dependent to
            driver and channel parameter)

         POSSIBILITIES -

            comma separated list of possible values for this parameter,
            character strings are encapsulated into apostrophes
            (optionally returned, dependent to driver and channel
            parameter)

      The mentioned fields above don't have to be in particular order.

   Example:


Schoenebeck            Expires September 12, 2019              [Page 27]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      C: "GET AUDIO_OUTPUT_CHANNEL_PARAMETER INFO 1 0 JACK_BINDINGS"

      S: "DESCRIPTION: bindings to other JACK clients"

      "TYPE: STRING"

      "FIX: false"

      "MULTIPLICITY: true"

      "POSSIBILITIES: 'PCM:0','PCM:1','ardour:0','ardour:1'"

      "."

6.2.13.  Changing settings of audio output channels

   Use the following command to alter a specific setting of an audio
   output channel:

      SET AUDIO_OUTPUT_CHANNEL_PARAMETER <dev-id> <chn> <key>=<value>

   Where <dev-id> should be replaced by the numerical ID of the audio
   output device as returned by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command, <chn> by the audio channel number, <key> by the name of the
   parameter to change and <value> by the new value for this parameter.

   Possible Answers:

      "OK" -

         in case setting was successfully changed

      "WRN:<warning-code>:<warning-message>" -

         in case setting was changed successfully, but there are
         noteworthy issue(s) related, providing an appropriate warning
         code and warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "SET AUDIO_OUTPUT_CHANNEL PARAMETER 0 0 JACK_BINDINGS='PCM:0'"


Schoenebeck            Expires September 12, 2019              [Page 28]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      S: "OK"

      C: "SET AUDIO_OUTPUT_CHANNEL PARAMETER 0 0 NAME='monitor left'"

      S: "OK"

6.3.  Configuring MIDI input drivers

   Instances of drivers in LinuxSampler are called devices.  You can use
   multiple MIDI devices simultaneously, e.g. to use MIDI over ethernet
   as MIDI input on one sampler channel and ALSA as MIDI input on
   another sampler channel.  For particular MIDI input systems it's also
   possible to create several devices of the same MIDI input type.  This
   chapter describes all commands to configure LinuxSampler's MIDI input
   devices and their parameters.

   Instead of defining commands and parameters for each driver
   individually, all possible parameters, their meanings and possible
   values have to be obtained at runtime.  This makes the protocol a bit
   abstract, but has the advantage, that front-ends can be written
   independently of what drivers are currently implemented and what
   parameters these drivers are actually offering.  This means front-
   ends can even handle drivers which are implemented somewhere in
   future without modifying the front-end at all.

   Commands for configuring MIDI input devices are pretty much the same
   as the commands for configuring audio output drivers, already
   described in the last chapter.

   Note: examples in this chapter showing particular parameters of
   drivers are not meant as specification of the drivers' parameters.
   Driver implementations in LinuxSampler might have complete different
   parameter names and meanings than shown in these examples or might
   change in future, so these examples are only meant for showing how to
   retrieve what parameters drivers are offering, how to retrieve their
   possible values, etc.

6.3.1.  Getting amount of available MIDI input drivers

   Use the following command to get the number of MIDI input drivers
   currently available for the LinuxSampler instance:

      GET AVAILABLE_MIDI_INPUT_DRIVERS

   Possible Answers:

      LinuxSampler will answer by sending the number of available MIDI
      input drivers.


Schoenebeck            Expires September 12, 2019              [Page 29]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Example:

      C: "GET AVAILABLE_MIDI_INPUT_DRIVERS"

      S: "2"

6.3.2.  Getting all available MIDI input drivers

   Use the following command to list all MIDI input drivers currently
   available for the LinuxSampler instance:

      LIST AVAILABLE_MIDI_INPUT_DRIVERS

   Possible Answers:

      LinuxSampler will answer by sending comma separated character
      strings, each symbolizing a MIDI input driver.

   Example:

      C: "LIST AVAILABLE_MIDI_INPUT_DRIVERS"

      S: "ALSA,JACK"

6.3.3.  Getting information about a specific MIDI input driver

   Use the following command to get detailed information about a
   specific MIDI input driver:

      GET MIDI_INPUT_DRIVER INFO <midi-input-driver>

   Where <midi-input-driver> is the name of the MIDI input driver as
   returned by the "LIST AVAILABLE_MIDI_INPUT_DRIVERS" (Section 6.3.2)
   command.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that info category.  At the moment the
      following information categories are defined:


         DESCRIPTION -

            arbitrary description text about the MIDI input driver


Schoenebeck            Expires September 12, 2019              [Page 30]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         VERSION -

            arbitrary character string regarding the driver's version

         PARAMETERS -

            comma separated list of all parameters available for the
            given MIDI input driver

      The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET MIDI_INPUT_DRIVER INFO ALSA"

      S: "DESCRIPTION: Advanced Linux Sound Architecture"

      "VERSION: 1.0"

      "PARAMETERS: DRIVER,ACTIVE"

      "."

6.3.4.  Getting information about specific MIDI input driver parameter

   Use the following command to get detailed information about a
   specific parameter of a specific MIDI input driver:

      GET MIDI_INPUT_DRIVER_PARAMETER INFO <midit> <param> [<deplist>]

   Where <midit> is the name of the MIDI input driver as returned by the
   "LIST AVAILABLE_MIDI_INPUT_DRIVERS" (Section 6.3.2) command, <param>
   a specific parameter name for which information should be obtained
   (as returned by the "GET MIDI_INPUT_DRIVER INFO" (Section 6.3.3)
   command) and <deplist> is an optional list of parameters on which the
   sought parameter <param> depends on, <deplist> is a key-value pair
   list in form of "key1=val1 key2=val2 ...", where character string
   values are encapsulated into apostrophes (').  Arguments given with
   <deplist> which are not dependency parameters of <param> will be
   ignored, means the front-end application can simply put all
   parameters in <deplist> with the values selected by the user.

   Possible Answers:

   LinuxSampler will answer by sending a <CRLF> separated list.  Each
   answer line begins with the information category name followed by a
   colon and then a space character <SP> and finally the info character
   string to that info category.  There is information which is always


Schoenebeck            Expires September 12, 2019              [Page 31]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   returned, independent of the given driver parameter and there is
   optional information which is only shown dependent to given driver
   parameter.  At the moment the following information categories are
   defined:

      TYPE -

         either "BOOL" for boolean value(s) or "INT" for integer
         value(s) or "FLOAT" for dotted number(s) or "STRING" for
         character string(s) (always returned, no matter which driver
         parameter)

      DESCRIPTION -

         arbitrary text describing the purpose of the parameter (always
         returned, no matter which driver parameter)

      MANDATORY -

         either true or false, defines if this parameter must be given
         when the device is to be created with the 'CREATE
         MIDI_INPUT_DEVICE' (Section 6.3.5) command (always returned, no
         matter which driver parameter)

      FIX -

         either true or false, if false then this parameter can be
         changed at any time, once the device is created by the 'CREATE
         MIDI_INPUT_DEVICE' (Section 6.3.5) command (always returned, no
         matter which driver parameter)

      MULTIPLICITY -

         either true or false, defines if this parameter allows only one
         value or a list of values, where true means multiple values and
         false only a single value allowed (always returned, no matter
         which driver parameter)

      DEPENDS -

         comma separated list of parameters this parameter depends on,
         means the values for fields 'DEFAULT', 'RANGE_MIN', 'RANGE_MAX'
         and 'POSSIBILITIES' might depend on these listed parameters,
         for example assuming that an audio driver (like the ALSA
         driver) offers parameters 'card' and 'samplerate' then
         parameter 'samplerate' would depend on 'card' because the
         possible values for 'samplerate' depends on the sound card


Schoenebeck            Expires September 12, 2019              [Page 32]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         which can be chosen by the 'card' parameter (optionally
         returned, dependent to driver parameter)

      DEFAULT -

         reflects the default value for this parameter which is used
         when the device is created and not explicitly given with the
         'CREATE MIDI_INPUT_DEVICE' (Section 6.3.5) command, in case of
         MULTIPLCITY=true, this is a comma separated list, that's why
         character strings are encapsulated into apostrophes (')
         (optionally returned, dependent to driver parameter)

      RANGE_MIN -

         defines lower limit of the allowed value range for this
         parameter, can be an integer value as well as a dotted number,
         this parameter is often used in conjunction with RANGE_MAX, but
         may also appear without (optionally returned, dependent to
         driver parameter)

      RANGE_MAX -

         defines upper limit of the allowed value range for this
         parameter, can be an integer value as well as a dotted number,
         this parameter is often used in conjunction with RANGE_MIN, but
         may also appear without (optionally returned, dependent to
         driver parameter)

      POSSIBILITIES -

         comma separated list of possible values for this parameter,
         character strings are encapsulated into apostrophes (optionally
         returned, dependent to driver parameter)

   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET MIDI_INPUT_DRIVER_PARAMETER INFO ALSA ACTIVE"

      S: "DESCRIPTION: Whether device is enabled"

      "TYPE: BOOL"

      "MANDATORY: false"

      "FIX: false"


Schoenebeck            Expires September 12, 2019              [Page 33]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "MULTIPLICITY: false"

      "DEFAULT: true"

      "."

6.3.5.  Creating a MIDI input device

   Use the following command to create a new MIDI input device for the
   desired MIDI input system:

      CREATE MIDI_INPUT_DEVICE <midi-input-driver> [<param-list>]

   Where <midi-input-driver> should be replaced by the desired MIDI
   input system as returned by the "LIST AVAILABLE_MIDI_INPUT_DRIVERS"
   (Section 6.3.2) command and <param-list> by an optional list of
   driver specific parameters in form of "key1=val1 key2=val2 ...",
   where character string values should be encapsulated into apostrophes
   (').  Note that there might be drivers which require parameter(s) to
   be given with this command.  Use the previously described commands in
   this chapter to get that information.

   Possible Answers:

      "OK[<device-id>]" -

         in case the device was successfully created, where <device-id>
         is the numerical ID of the new device

      "WRN[<device-id>]:<warning-code>:<warning-message>" -

         in case the driver was loaded successfully, where <device-id>
         is the numerical ID of the new device, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "CREATE MIDI_INPUT_DEVICE ALSA"

      S: "OK[0]"


Schoenebeck            Expires September 12, 2019              [Page 34]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.3.6.  Destroying a MIDI input device

   Use the following command to destroy a created MIDI input device:

      DESTROY MIDI_INPUT_DEVICE <device-id>

   Where <device-id> should be replaced by the device's numerical ID as
   returned by the "CREATE MIDI_INPUT_DEVICE" (Section 6.3.5) or "LIST
   MIDI_INPUT_DEVICES" (Section 6.3.8) command.

   Possible Answers:

      "OK" -

         in case the device was successfully destroyed

      "WRN:<warning-code>:<warning-message>" -

         in case the device was destroyed, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "DESTROY MIDI_INPUT_DEVICE 0"

      S: "OK"

6.3.7.  Getting all created MIDI input device count

   Use the following command to count all created MIDI input devices:

      GET MIDI_INPUT_DEVICES

   Possible Answers:

      LinuxSampler will answer by sending the current number of all MIDI
      input devices.

   Example:

      C: "GET MIDI_INPUT_DEVICES"


Schoenebeck            Expires September 12, 2019              [Page 35]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      S: "3"

6.3.8.  Getting all created MIDI input device list

   Use the following command to list all created MIDI input devices:

      LIST MIDI_INPUT_DEVICES

   Possible Answers:

      LinuxSampler will answer by sending a comma separated list with
      the numerical Ids of all created MIDI input devices.

   Examples:

      C: "LIST MIDI_INPUT_DEVICES"

      S: "0,1,2"

      C: "LIST MIDI_INPUT_DEVICES"

      S: "1,3"

6.3.9.  Getting current settings of a MIDI input device

   Use the following command to get current settings of a specific,
   created MIDI input device:

      GET MIDI_INPUT_DEVICE INFO <device-id>

   Where <device-id> is the numerical ID of the MIDI input device as
   returned by the "CREATE MIDI_INPUT_DEVICE" (Section 6.3.5) or "LIST
   MIDI_INPUT_DEVICES" (Section 6.3.8) command.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that info category.  As some parameters might
      allow multiple values, character strings are encapsulated into
      apostrophes (').  At the moment the following information
      categories are defined (independent of driver):


         DRIVER -


Schoenebeck            Expires September 12, 2019              [Page 36]

Internet-Draft        LinuxSampler Control Protocol           March 2019


            identifier of the used MIDI input driver, as e.g.  returned
            by the "LIST AVAILABLE_MIDI_INPUT_DRIVERS" (Section 6.3.2)
            command

         ACTIVE -

            either true or false, if false then the MIDI device is
            inactive and doesn't listen to any incoming MIDI events and
            thus doesn't forward them to connected sampler channels

   The mentioned fields above don't have to be in particular order.  The
   fields above are only those fields which are returned by all MIDI
   input devices.  Every MIDI input driver might have its own,
   additional driver specific parameters (see "GET MIDI_INPUT_DRIVER
   INFO" (Section 6.3.3) command) which are also returned by this
   command.

   Example:

      C: "GET MIDI_INPUT_DEVICE INFO 0"

      S: "DRIVER: ALSA"

      "ACTIVE: true"

      "."

6.3.10.  Changing settings of MIDI input devices

   Use the following command to alter a specific setting of a created
   MIDI input device:

      SET MIDI_INPUT_DEVICE_PARAMETER <device-id> <key>=<value>

   Where <device-id> should be replaced by the numerical ID of the MIDI
   input device as returned by the "CREATE MIDI_INPUT_DEVICE"
   (Section 6.3.5) or "LIST MIDI_INPUT_DEVICES" (Section 6.3.8) command,
   <key> by the name of the parameter to change and <value> by the new
   value for this parameter.

   Possible Answers:

      "OK" -

         in case setting was successfully changed

      "WRN:<warning-code>:<warning-message>" -


Schoenebeck            Expires September 12, 2019              [Page 37]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         in case setting was changed successfully, but there are
         noteworthy issue(s) related, providing an appropriate warning
         code and warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "SET MIDI_INPUT_DEVICE_PARAMETER 0 ACTIVE=false"

      S: "OK"

6.3.11.  Getting information about a MIDI port

   Use the following command to get information about a MIDI port:

      GET MIDI_INPUT_PORT INFO <device-id> <midi-port>

   Where <device-id> is the numerical ID of the MIDI input device as
   returned by the "CREATE MIDI_INPUT_DEVICE" (Section 6.3.5) or "LIST
   MIDI_INPUT_DEVICES" (Section 6.3.8) command and <midi-port> the MIDI
   input port number.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that info category.  At the moment the
      following information categories are defined:

      NAME -

         arbitrary character string naming the port

   The field above is only the one which is returned by all MIDI ports
   regardless of the MIDI driver and port.  Every MIDI port might have
   its own, additional driver and port specific parameters.

   Example:

      C: "GET MIDI_INPUT_PORT INFO 0 0"

      S: "NAME: 'Masterkeyboard'"


Schoenebeck            Expires September 12, 2019              [Page 38]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "ALSA_SEQ_BINDINGS: '64:0'"

      "."

6.3.12.  Getting information about specific MIDI port parameter

   Use the following command to get detailed information about specific
   MIDI port parameter:

      GET MIDI_INPUT_PORT_PARAMETER INFO <dev-id> <port> <param>

   Where <dev-id> is the numerical ID of the MIDI input device as
   returned by the "CREATE MIDI_INPUT_DEVICE" (Section 6.3.5) or "LIST
   MIDI_INPUT_DEVICES" (Section 6.3.8) command, <port> the MIDI port
   number and <param> a specific port parameter name for which
   information should be obtained (as returned by the "GET
   MIDI_INPUT_PORT INFO" (Section 6.3.11) command).

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that info category.  There is information
      which is always returned, independently of the given channel
      parameter and there is optional information which are only shown
      dependently to the given MIDI port.  At the moment the following
      information categories are defined:

      TYPE -

         either "BOOL" for boolean value(s) or "INT" for integer
         value(s) or "FLOAT" for dotted number(s) or "STRING" for
         character string(s) (always returned)

      DESCRIPTION -

         arbitrary text describing the purpose of the parameter (always
         returned)

      FIX -

         either true or false, if true then this parameter is read only,
         thus cannot be altered (always returned)

      MULTIPLICITY -


Schoenebeck            Expires September 12, 2019              [Page 39]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         either true or false, defines if this parameter allows only one
         value or a list of values, where true means multiple values and
         false only a single value allowed (always returned)

      RANGE_MIN -

         defines lower limit of the allowed value range for this
         parameter, can be an integer value as well as a dotted number,
         this parameter is usually used in conjunction with 'RANGE_MAX'
         but may also appear without (optionally returned, dependent to
         driver and port parameter)

      RANGE_MAX -

         defines upper limit of the allowed value range for this
         parameter, can be an integer value as well as a dotted number,
         this parameter is usually used in conjunction with 'RANGE_MIN'
         but may also appear without (optionally returned, dependent to
         driver and port parameter)

      POSSIBILITIES -

         comma separated list of possible values for this parameter,
         character strings are encapsulated into apostrophes (optionally
         returned, dependent to device and port parameter)

   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET MIDI_INPUT_PORT_PARAMETER INFO 0 0 ALSA_SEQ_BINDINGS"

      S: "DESCRIPTION: bindings to other ALSA sequencer clients"

      "TYPE: STRING"

      "FIX: false"

      "MULTIPLICITY: true"

      "POSSIBILITIES: '64:0','68:0','68:1'"

      "."


Schoenebeck            Expires September 12, 2019              [Page 40]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.3.13.  Changing settings of MIDI input ports

   Use the following command to alter a specific setting of a MIDI input
   port:

      SET MIDI_INPUT_PORT_PARAMETER <device-id> <port> <key>=<value>

   Where <device-id> should be replaced by the numerical ID of the MIDI
   device as returned by the "CREATE MIDI_INPUT_DEVICE" (Section 6.3.5)
   or "LIST MIDI_INPUT_DEVICES" (Section 6.3.8) command, <port> by the
   MIDI port number, <key> by the name of the parameter to change and
   <value> by the new value for this parameter (encapsulated into
   apostrophes) or NONE (not encapsulated into apostrophes) for
   specifying no value for parameters allowing a list of values.

   Possible Answers:

      "OK" -

         in case setting was successfully changed

      "WRN:<warning-code>:<warning-message>" -

         in case setting was changed successfully, but there are
         noteworthy issue(s) related, providing an appropriate warning
         code and warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "SET MIDI_INPUT_PORT_PARAMETER 0 0 ALSA_SEQ_BINDINGS='20:0'"

      S: "OK"

      C: "SET MIDI_INPUT_PORT_PARAMETER 0 0 ALSA_SEQ_BINDINGS=NONE"

      S: "OK"

6.4.  Configuring sampler channels

   The following commands describe how to add and remove sampler
   channels, associate a sampler channel with a sampler engine, load
   instruments and connect sampler channels to MIDI and audio devices.


Schoenebeck            Expires September 12, 2019              [Page 41]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.4.1.  Loading an instrument

   An instrument file can be loaded and assigned to a sampler channel by
   one of the following commands:

      LOAD INSTRUMENT [NON_MODAL] '<filename>' <instr-index> <sampler-
      channel>

   Where <filename> is the name of the instrument file on the
   LinuxSampler instance's host system, <instr-index> the index of the
   instrument in the instrument file and <sampler-channel> is the number
   of the sampler channel the instrument should be assigned to.  Each
   sampler channel can only have one instrument.

   Notice: since LSCP 1.2 the <filename> argument supports escape
   characters for special characters (see chapter "Character Set and
   Escape Sequences (Section 7.1)" for details) and accordingly
   backslash characters in the filename MUST now be escaped as well!

   The difference between regular and NON_MODAL versions of the command
   is that the regular command returns OK only after the instrument has
   been fully loaded and the channel is ready to be used while NON_MODAL
   version returns immediately and a background process is launched to
   load the instrument on the channel.  The GET CHANNEL INFO
   (Section 6.4.10) command can be used to obtain loading progress from
   INSTRUMENT_STATUS field.  LOAD command will perform sanity checks
   such as making sure that the file could be read and it is of a proper
   format and SHOULD return ERR and SHOULD not launch the background
   process should any errors be detected at that point.

   Possible Answers:

      "OK" -

         in case the instrument was successfully loaded

      "WRN:<warning-code>:<warning-message>" -

         in case the instrument was loaded successfully, but there are
         noteworthy issue(s) related (e.g.  Engine doesn't support one
         or more patch parameters provided by the loaded instrument
         file), providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message


Schoenebeck            Expires September 12, 2019              [Page 42]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Example (Unix):

      C: LOAD INSTRUMENT '/home/joe/gigs/cello.gig' 0 0

      S: OK

   Example (Windows):

      C: LOAD INSTRUMENT 'D:/MySounds/cello.gig' 0 0

      S: OK

6.4.2.  Loading a sampler engine

   A sampler engine type can be associated to a specific sampler channel
   by the following command:

      LOAD ENGINE <engine-name> <sampler-channel>

   Where <engine-name> is an engine name as obtained by the "LIST
   AVAILABLE_ENGINES" (Section 6.4.8) command and <sampler-channel> the
   sampler channel as returned by the "ADD CHANNEL" (Section 6.4.5) or
   "LIST CHANNELS" (Section 6.4.4) command where the engine type should
   be assigned to.  This command should be issued after adding a new
   sampler channel and before any other control commands on the new
   sampler channel.  It can also be used to change the engine type of a
   sampler channel.  This command has (currently) no way to define or
   force if a new engine instance should be created and assigned to the
   given sampler channel or if an already existing instance of that
   engine type, shared with other sampler channels, should be used.

   Possible Answers:

      "OK" -

         in case the engine was successfully deployed

      "WRN:<warning-code>:<warning-message>" -

         in case the engine was deployed successfully, but there are
         noteworthy issue(s) related, providing an appropriate warning
         code and warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message


Schoenebeck            Expires September 12, 2019              [Page 43]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Example:


6.4.3.  Getting all created sampler channel count

   The number of sampler channels can change on runtime.  To get the
   current amount of sampler channels, the front-end can send the
   following command:

      GET CHANNELS

   Possible Answers:

      LinuxSampler will answer by returning the current number of
      sampler channels.

   Example:

      C: "GET CHANNELS"

      S: "12"

6.4.4.  Getting all created sampler channel list

   The number of sampler channels can change on runtime.  To get the
   current list of sampler channels, the front-end can send the
   following command:

      LIST CHANNELS

   Possible Answers:

      LinuxSampler will answer by returning a comma separated list with
      all sampler channels numerical IDs.

   Example:

      C: "LIST CHANNELS"

      S: "0,1,2,3,4,5,6,9,10,11,15,20"

6.4.5.  Adding a new sampler channel

   A new sampler channel can be added to the end of the sampler channel
   list by sending the following command:

      ADD CHANNEL


Schoenebeck            Expires September 12, 2019              [Page 44]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   This will increment the sampler channel count by one and the new
   sampler channel will be appended to the end of the sampler channel
   list.  The front-end should send the respective, related commands
   right after to e.g. load an engine, load an instrument and setting
   input, output method and eventually other commands to initialize the
   new channel.  The front-end should use the sampler channel returned
   by the answer of this command to perform the previously recommended
   commands, to avoid race conditions e.g. with other front-ends that
   might also have sent an "ADD CHANNEL" command.

   Possible Answers:

      "OK[<sampler-channel>]" -

         in case a new sampler channel could be added, where <sampler-
         channel> reflects the channel number of the new created sampler
         channel which should be used to set up the sampler channel by
         sending subsequent initialization commands

      "WRN:<warning-code>:<warning-message>" -

         in case a new channel was added successfully, but there are
         noteworthy issue(s) related, providing an appropriate warning
         code and warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:


6.4.6.  Removing a sampler channel

   A sampler channel can be removed by sending the following command:

      REMOVE CHANNEL <sampler-channel>

   Where <sampler-channel> should be replaced by the number of the
   sampler channel as given by the "ADD CHANNEL" (Section 6.4.5) or
   "LIST CHANNELS" (Section 6.4.4) command.  The channel numbers of all
   subsequent sampler channels remain the same.

   Possible Answers:

      "OK" -


Schoenebeck            Expires September 12, 2019              [Page 45]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         in case the given sampler channel could be removed

      "WRN:<warning-code>:<warning-message>" -

         in case the given channel was removed, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:


6.4.7.  Getting amount of available engines

   The front-end can ask for the number of available engines by sending
   the following command:

      GET AVAILABLE_ENGINES

   Possible Answers:

      LinuxSampler will answer by sending the number of available
      engines.

   Example:

      C: "GET AVAILABLE_ENGINES"

      S: "4"

6.4.8.  Getting all available engines

   The front-end can ask for a list of all available engines by sending
   the following command:

      LIST AVAILABLE_ENGINES

   Possible Answers:

      LinuxSampler will answer by sending a comma separated list of the
      engines' names encapsulated into apostrophes (').  Engine names
      can consist of lower and upper cases, digits and underlines ("_"
      character).


Schoenebeck            Expires September 12, 2019              [Page 46]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Example:

      C: "LIST AVAILABLE_ENGINES"

      S: "'gig','sfz','sf2'"

6.4.9.  Getting information about an engine

   The front-end can ask for information about a specific engine by
   sending the following command:

      GET ENGINE INFO <engine-name>

   Where <engine-name> is an engine name as obtained by the "LIST
   AVAILABLE_ENGINES" (Section 6.4.8) command.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that info category.  At the moment the
      following categories are defined:


         DESCRIPTION -

            arbitrary description text about the engine (note that the
            character string may contain escape sequences (Section 7.1))

         VERSION -

            arbitrary character string regarding the engine's version

   The mentioned fields above don't have to be in particular order.

   Examples:

      C: "GET ENGINE INFO gig"

      S: "DESCRIPTION: GigaSampler Format Engine"

      "VERSION: 1.110"

      "."

      C: "GET ENGINE INFO sf2"


Schoenebeck            Expires September 12, 2019              [Page 47]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      S: "DESCRIPTION: SoundFont Format Engine"

      "VERSION: 1.4"

      "."

      C: "GET ENGINE INFO sfz"

      S: "DESCRIPTION: SFZ Format Engine"

      "VERSION: 1.11"

      "."

6.4.10.  Getting sampler channel information

   The front-end can ask for the current settings of a sampler channel
   by sending the following command:

      GET CHANNEL INFO <sampler-channel>

   Where <sampler-channel> is the sampler channel number the front-end
   is interested in as returned by the "ADD CHANNEL" (Section 6.4.5) or
   "LIST CHANNELS" (Section 6.4.4) command.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the settings category name followed by a
      colon and then a space character <SP> and finally the info
      character string to that setting category.  At the moment the
      following categories are defined:


         ENGINE_NAME -

            name of the engine that is associated with the sampler
            channel, "NONE" if there's no engine associated yet for this
            sampler channel

         AUDIO_OUTPUT_DEVICE -

            numerical ID of the audio output device which is currently
            connected to this sampler channel to output the audio
            signal, "-1" if there's no device connected to this sampler
            channel


Schoenebeck            Expires September 12, 2019              [Page 48]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         AUDIO_OUTPUT_CHANNELS -

            number of output channels the sampler channel offers
            (dependent to used sampler engine and loaded instrument)

         AUDIO_OUTPUT_ROUTING -

            comma separated list which reflects to which audio channel
            of the selected audio output device each sampler output
            channel is routed to, e.g. "0,3" would mean the engine's
            output channel 0 is routed to channel 0 of the audio output
            device and the engine's output channel 1 is routed to the
            channel 3 of the audio output device

         INSTRUMENT_FILE -

            the file name of the loaded instrument, "NONE" if there's no
            instrument yet loaded for this sampler channel (note: since
            LSCP 1.2 this path may contain escape sequences
            (Section 7.1))

         INSTRUMENT_NR -

            the instrument index number of the loaded instrument, "-1"
            if there's no instrument loaded for this sampler channel

         INSTRUMENT_NAME -

            the instrument name of the loaded instrument (note: since
            LSCP 1.2 this character string may contain escape sequences
            (Section 7.1))

         INSTRUMENT_STATUS -

            Integer values 0 to 100 indicating loading progress
            percentage for the instrument.  Negative value indicates a
            loading exception (also returns "-1" in case no instrument
            was yet to be loaded on the sampler channel).  Value of 100
            indicates that the instrument is fully loaded.

         MIDI_INPUT_DEVICE -

            DEPRECATED: THIS FIELD WILL DISAPPEAR!

            numerical ID of the MIDI input device which is currently
            connected to this sampler channel to deliver MIDI input
            commands, "-1" if there's no device connected to this
            sampler channel


Schoenebeck            Expires September 12, 2019              [Page 49]

Internet-Draft        LinuxSampler Control Protocol           March 2019


            Should not be used anymore as of LSCP v1.6 and younger.
            This field is currently only preserved for backward
            compatibility.

            This field a relict from times where only one MIDI input per
            sampler channel was allowed.  Use "GET CHANNEL MIDI_INPUTS"
            (Section 6.4.19) instead.

         MIDI_INPUT_PORT -

            DEPRECATED: THIS FIELD WILL DISAPPEAR!

            port number of the MIDI input device (in case a MIDI device
            was already assigned to the sampler channel)

            Should not be used anymore as of LSCP v1.6 and younger.
            This field is currently only preserved for backward
            compatibility.

            This field a relict from times where only one MIDI input per
            sampler channel was allowed.  Use "GET CHANNEL MIDI_INPUTS"
            (Section 6.4.19) instead.

         MIDI_INPUT_CHANNEL -

            the MIDI input channel number this sampler channel should
            listen to or "ALL" to listen on all MIDI channels

         VOLUME -

            optionally dotted number for the channel volume factor
            (where a value < 1.0 means attenuation and a value > 1.0
            means amplification)

         MUTE -

            Determines whether the channel is muted, "true" if the
            channel is muted, "false" if the channel is not muted, and
            "MUTED_BY_SOLO" if the channel is muted because of the
            presence of a solo channel and will be unmuted when there
            are no solo channels left

         SOLO -

            Determines whether this is a solo channel, "true" if the
            channel is a solo channel; "false" otherwise

         MIDI_INSTRUMENT_MAP -


Schoenebeck            Expires September 12, 2019              [Page 50]

Internet-Draft        LinuxSampler Control Protocol           March 2019


            Determines to which MIDI instrument map this sampler channel
            is assigned to.  Read chapter "SET CHANNEL
            MIDI_INSTRUMENT_MAP" (Section 6.4.27) for a list of possible
            values.

   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET CHANNEL INFO 34"

      S: "ENGINE_NAME: gig"

      "VOLUME: 1.0"

      "AUDIO_OUTPUT_DEVICE: 0"

      "AUDIO_OUTPUT_CHANNELS: 2"

      "AUDIO_OUTPUT_ROUTING: 0,1"

      "INSTRUMENT_FILE: /home/joe/FazioliPiano.gig"

      "INSTRUMENT_NR: 0"

      "INSTRUMENT_NAME: Fazioli Piano"

      "INSTRUMENT_STATUS: 100"

      "MIDI_INPUT_DEVICE: 0"

      "MIDI_INPUT_PORT: 0"

      "MIDI_INPUT_CHANNEL: 5"

      "VOLUME: 1.0"

      "MUTE: false"

      "SOLO: false"

      "MIDI_INSTRUMENT_MAP: NONE"

      "."


Schoenebeck            Expires September 12, 2019              [Page 51]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.4.11.  Current number of active voices

   The front-end can ask for the current number of active voices on a
   sampler channel by sending the following command:

      GET CHANNEL VOICE_COUNT <sampler-channel>

   Where <sampler-channel> is the sampler channel number the front-end
   is interested in as returned by the "ADD CHANNEL" (Section 6.4.5) or
   "LIST CHANNELS" (Section 6.4.4) command.

   Possible Answers:

      LinuxSampler will answer by returning the number of active voices
      on that channel.

   Example:


6.4.12.  Current number of active disk streams

   The front-end can ask for the current number of active disk streams
   on a sampler channel by sending the following command:

      GET CHANNEL STREAM_COUNT <sampler-channel>

   Where <sampler-channel> is the sampler channel number the front-end
   is interested in as returned by the "ADD CHANNEL" (Section 6.4.5) or
   "LIST CHANNELS" (Section 6.4.4) command.

   Possible Answers:

      LinuxSampler will answer by returning the number of active disk
      streams on that channel in case the engine supports disk
      streaming, if the engine doesn't support disk streaming it will
      return "NA" for not available.

   Example:


6.4.13.  Current fill state of disk stream buffers

   The front-end can ask for the current fill state of all disk streams
   on a sampler channel by sending the following command:

      GET CHANNEL BUFFER_FILL BYTES <sampler-channel>


Schoenebeck            Expires September 12, 2019              [Page 52]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   to get the fill state in bytes or

      GET CHANNEL BUFFER_FILL PERCENTAGE <sampler-channel>

   to get the fill state in percent, where <sampler-channel> is the
   sampler channel number the front-end is interested in as returned by
   the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command.

   Possible Answers:

      LinuxSampler will either answer by returning a comma separated
      string with the fill state of all disk stream buffers on that
      channel or an empty line if there are no active disk streams or
      "NA" for *not available* in case the engine which is deployed
      doesn't support disk streaming.  Each entry in the answer list
      will begin with the stream's ID in brackets followed by the
      numerical representation of the fill size (either in bytes or
      percentage).  Note: due to efficiency reasons the fill states in
      the response are not in particular order, thus the front-end has
      to sort them by itself if necessary.

   Examples:

      C: "GET CHANNEL BUFFER_FILL BYTES 4"

      S: "[115]420500,[116]510300,[75]110000,[120]230700"

      C: "GET CHANNEL BUFFER_FILL PERCENTAGE 4"

      S: "[115]90%,[116]98%,[75]40%,[120]62%"

      C: "GET CHANNEL BUFFER_FILL PERCENTAGE 4"

      S: ""

6.4.14.  Setting audio output device

   The front-end can set the audio output device on a specific sampler
   channel by sending the following command:

      SET CHANNEL AUDIO_OUTPUT_DEVICE <sampler-channel> <audio-device-
      id>

   Where <sampler-channel> is the respective sampler channel number as
   returned by the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS"
   (Section 6.4.4) command and <audio-device-id> is the numerical ID of
   the audio output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"


Schoenebeck            Expires September 12, 2019              [Page 53]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if audio output device was set, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:


6.4.15.  Setting audio output type

   DEPRECATED: THIS COMMAND WILL DISAPPEAR!

   The front-end can alter the audio output type on a specific sampler
   channel by sending the following command:

      SET CHANNEL AUDIO_OUTPUT_TYPE <sampler-channel> <audio-output-
      type>

   Where <audio-output-type> is currently either "ALSA" or "JACK" and
   <sampler-channel> is the respective sampler channel number.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if audio output type was set, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message


Schoenebeck            Expires September 12, 2019              [Page 54]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:


   Deprecated:

      Should not be used anymore.  This command is currently only
      preserved for backward compatibility.

      This command is a relict from times where there was no
      sophisticated driver management yet.  Use "CREATE
      AUDIO_OUTPUT_DEVICE" (Section 6.2.5) and "SET CHANNEL
      AUDIO_OUTPUT_DEVICE" (Section 6.4.14) instead.

6.4.16.  Setting audio output channel

   The front-end can alter the audio output channel on a specific
   sampler channel by sending the following command:

      SET CHANNEL AUDIO_OUTPUT_CHANNEL <sampler-chan> <audio-out>
      <audio-in>

   Where <sampler-chan> is the sampler channel number as returned by the
   "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command, <audio-out> is the numerical ID of the sampler channel's
   audio output channel which should be rerouted and <audio-in> is the
   numerical ID of the audio channel of the selected audio output device
   where <audio-out> should be routed to.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if audio output channel was set, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -


Schoenebeck            Expires September 12, 2019              [Page 55]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         in case it failed, providing an appropriate error code and
         error message

   Examples:


6.4.17.  Add MIDI input to sampler channel

   The front-end can add a MIDI input on a specific sampler channel by
   sending the following command:

      ADD CHANNEL MIDI_INPUT <sampler-channel> <midi-device-id> [<midi-
      input-port>]

   Where <sampler-channel> is the sampler channel number as returned by
   the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command and <midi-device-id> is the numerical ID of the MIDI input
   device as returned by the "CREATE MIDI_INPUT_DEVICE" (Section 6.3.5)
   or "LIST MIDI_INPUT_DEVICES" (Section 6.3.8) command, and <midi-
   input-port> is an optional MIDI input port number of that MIDI input
   device.  If <midi-input-port> is omitted, then the MIDI input
   device's first port (port number 0) is used.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if MIDI input port was connected, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:

      C: "ADD CHANNEL MIDI_INPUT 0 0"

      S: "OK"

      C: "ADD CHANNEL MIDI_INPUT 1 0"


Schoenebeck            Expires September 12, 2019              [Page 56]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      S: "OK"

      C: "ADD CHANNEL MIDI_INPUT 1 1 1"

      S: "OK"

      C: "ADD CHANNEL MIDI_INPUT 1 2 0"

      S: "OK"

   Since:

      Introduced with LSCP v1.6

6.4.18.  Remove MIDI input(s) from sampler channel

   The front-end can remove one ore more MIDI input(s) on a specific
   sampler channel by sending the following command:

      REMOVE CHANNEL MIDI_INPUT <sampler-channel> [<midi-device-id>
      [<midi-input-port>]]

   Where <sampler-channel> is the sampler channel number as returned by
   the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command and <midi-device-id> and <midi-input-port> are optional
   numerical IDs defining the MIDI input device and one of its MIDI
   ports as returned by the "LIST CHANNEL MIDI_INPUTS" (Section 6.4.19)
   command.

   If <midi-input-port> is omitted, then all MIDI input ports of <midi-
   device-id> are disconnected from this sampler channel.

   If both, <midi-device-id> and <midi-input-port> are omitted, then all
   MIDI input ports currently connected to this sampler channel are
   disconnected from this sampler channel.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if MIDI input porst were disconnected, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message


Schoenebeck            Expires September 12, 2019              [Page 57]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:

      C: "REMOVE CHANNEL MIDI_INPUT 0"

      S: "OK"

      C: "REMOVE CHANNEL MIDI_INPUT 1"

      S: "OK"

      C: "REMOVE CHANNEL MIDI_INPUT 1 2 0"

      S: "OK"

   Since:

      Introduced with LSCP v1.6

6.4.19.  Getting all MIDI inputs of a sampler channel

   The front-end can query a list of all currently connected MIDI inputs
   of a certain sampler channel by sending the following command:

      LIST CHANNEL MIDI_INPUTS <sampler-channel>

   Where <sampler-channel> is the sampler channel number as returned by
   the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command.

   Possible Answers:

      The sampler will answer by sending a comma separated list of MIDI
      input device ID - MIDI input port number pairs, where each pair is
      encapsulated into curly braces.  The list is returned in one
      single line.  The MIDI input device ID corresponds to the number
      returned by "LIST MIDI_INPUT_DEVICES" (Section 6.3.8) and the port
      number is the index of the respective MIDI port of that MIDI input
      device.

   Example:

      C: "LIST CHANNEL MIDI_INPUTS 0"


Schoenebeck            Expires September 12, 2019              [Page 58]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      S: "{0,0},{1,3},{2,0}"

   Since:

      Introduced with LSCP v1.6

6.4.20.  Setting MIDI input device

   DEPRECATED: THIS COMMAND WILL DISAPPEAR!

   The front-end can set the MIDI input device on a specific sampler
   channel by sending the following command:

      SET CHANNEL MIDI_INPUT_DEVICE <sampler-channel> <midi-device-id>

   Where <sampler-channel> is the sampler channel number as returned by
   the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command and <midi-device-id> is the numerical ID of the MIDI input
   device as returned by the "CREATE MIDI_INPUT_DEVICE" (Section 6.3.5)
   or "LIST MIDI_INPUT_DEVICES" (Section 6.3.8) command.

   If more than 1 MIDI inputs are currently connected to this sampler
   channel: Sending this command will disconnect ALL currently connected
   MIDI input ports connected to this sampler channel before
   establishing the new MIDI input connection.  So this command does NOT
   add the connection, it replaces all existing ones instead.  This
   behavior is due to preserving full behavior backward compatibility.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if MIDI input device was set, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:


Schoenebeck            Expires September 12, 2019              [Page 59]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Deprecated:

      Should not be used anymore as of LSCP v1.6 and younger.  This
      command is currently only preserved for backward compatibility.

      This command is a relict from times where only one MIDI input per
      sampler channel was allowed.  Use "ADD CHANNEL MIDI_INPUT"
      (Section 6.4.17) and "REMOVE CHANNEL MIDI_INPUT" (Section 6.4.18)
      instead.

6.4.21.  Setting MIDI input type

   DEPRECATED: THIS COMMAND WILL DISAPPEAR!

   The front-end can alter the MIDI input type on a specific sampler
   channel by sending the following command:

      SET CHANNEL MIDI_INPUT_TYPE <sampler-channel> <midi-input-type>

   Where <midi-input-type> is currently only "ALSA" and <sampler-
   channel> is the respective sampler channel number.

   If more than 1 MIDI inputs are currently connected to this sampler
   channel: Sending this command will disconnect ALL currently connected
   MIDI input ports connected to this sampler channel before
   establishing the new MIDI input connection.  So this command does NOT
   add the connection, it replaces all existing ones instead.  This
   behavior is due to preserving full behavior backward compatibility.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if MIDI input type was set, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:


Schoenebeck            Expires September 12, 2019              [Page 60]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Deprecated:

      Should not be used anymore.  This command is currently only
      preserved for backward compatibility.

      This command is a relict from times where only 1 MIDI input per
      sampler channels was allowed and where no sophisticated driver
      management existed yet.  Use "ADD CHANNEL MIDI_INPUT"
      (Section 6.4.17) and "REMOVE CHANNEL MIDI_INPUT" (Section 6.4.18)
      instead.

6.4.22.  Setting MIDI input port

   DEPRECATED: THIS COMMAND WILL DISAPPEAR!

   The front-end can alter the MIDI input port on a specific sampler
   channel by sending the following command:

      SET CHANNEL MIDI_INPUT_PORT <sampler-channel> <midi-input-port>

   Where <midi-input-port> is a MIDI input port number of the MIDI input
   device connected to the sampler channel given by <sampler-channel>.

   If more than 1 MIDI inputs are currently connected to this sampler
   channel: Sending this command will switch the connection of the first
   (and only the first) MIDI input port currently being connected to
   this sampler channel, to another port of the same MIDI input device.
   Or in other words: the first MIDI input port currently connected to
   this sampler channel will be disconnected, and the requested other
   port of its MIDI input device will be connected to this sampler
   channel instead.  This behavior is due to preserving full behavior
   backward compatibility.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if MIDI input port was set, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -


Schoenebeck            Expires September 12, 2019              [Page 61]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         in case it failed, providing an appropriate error code and
         error message

   Examples:


   Deprecated:

      Should not be used anymore.  This command is currently only
      preserved for backward compatibility.

      This command is a relict from times where only one MIDI input per
      sampler channel was allowed.  Use "ADD CHANNEL MIDI_INPUT"
      (Section 6.4.17) and "REMOVE CHANNEL MIDI_INPUT" (Section 6.4.18)
      instead.

6.4.23.  Setting MIDI input channel

   The front-end can alter the MIDI channel a sampler channel should
   listen to by sending the following command:

      SET CHANNEL MIDI_INPUT_CHANNEL <sampler-channel> <midi-input-chan>

   Where <midi-input-chan> is the number of the new MIDI input channel
   (zero indexed!) where <sampler-channel> should listen to, or "ALL" to
   listen on all 16 MIDI channels.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if MIDI input channel was set, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:

      C: "SET CHANNEL MIDI_INPUT_CHANNEL 0 0"


Schoenebeck            Expires September 12, 2019              [Page 62]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      S: "OK"

      C: "SET CHANNEL MIDI_INPUT_CHANNEL 1 ALL"

      S: "OK"

6.4.24.  Setting channel volume

   The front-end can alter the volume of a sampler channel by sending
   the following command:

      SET CHANNEL VOLUME <sampler-channel> <volume>

   Where <volume> is an optionally dotted positive number (a value
   smaller than 1.0 means attenuation, whereas a value greater than 1.0
   means amplification) and <sampler-channel> defines the sampler
   channel where this volume factor should be set.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if channel volume was set, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:


6.4.25.  Muting a sampler channel

   The front-end can mute/unmute a specific sampler channel by sending
   the following command:

      SET CHANNEL MUTE <sampler-channel> <mute>

   Where <sampler-channel> is the respective sampler channel number as
   returned by the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS"


Schoenebeck            Expires September 12, 2019              [Page 63]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   (Section 6.4.4) command and <mute> should be replaced either by "1"
   to mute the channel or "0" to unmute the channel.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if the channel was muted/unmuted, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:


6.4.26.  Soloing a sampler channel

   The front-end can solo/unsolo a specific sampler channel by sending
   the following command:

      SET CHANNEL SOLO <sampler-channel> <solo>

   Where <sampler-channel> is the respective sampler channel number as
   returned by the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS"
   (Section 6.4.4) command and <solo> should be replaced either by "1"
   to solo the channel or "0" to unsolo the channel.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if the channel was soloed/unsoloed, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message


Schoenebeck            Expires September 12, 2019              [Page 64]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:


6.4.27.  Assigning a MIDI instrument map to a sampler channel

   The front-end can assign a MIDI instrument map to a specific sampler
   channel by sending the following command:

      SET CHANNEL MIDI_INSTRUMENT_MAP <sampler-channel> <map>

   Where <sampler-channel> is the respective sampler channel number as
   returned by the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS"
   (Section 6.4.4) command and <map> can have the following
   possibilites:

      "NONE" -

         This is the default setting.  In this case the sampler channel
         is not assigned any MIDI instrument map and thus will ignore
         all MIDI program change messages.

      "DEFAULT" -

         The sampler channel will always use the default MIDI instrument
         map to handle MIDI program change messages.

      numeric ID -

         You can assign a specific MIDI instrument map by replacing
         <map> with the respective numeric ID of the MIDI instrument map
         as returned by the "LIST MIDI_INSTRUMENT_MAPS" (Section 6.7.4)
         command.  Once that map will be deleted, the sampler channel
         would fall back to "NONE".

   Read chapter "MIDI Instrument Mapping" (Section 6.7) for details
   regarding MIDI instrument mapping.

   Possible Answers:

      "OK" -

         on success


Schoenebeck            Expires September 12, 2019              [Page 65]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:


6.4.28.  Adding an effect send to a sampler channel

   The front-end can create an additional effect send on a specific
   sampler channel by sending the following command:

      CREATE FX_SEND <sampler-channel> <midi-ctrl> [<name>]

   Where <sampler-channel> is the respective sampler channel number as
   returned by the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS"
   (Section 6.4.4) command, that is the sampler channel on which the
   effect send should be created on, <midi-ctrl> is a number between
   0..127 defining the MIDI controller which can alter the effect send
   level and <name> is an optional argument defining a name for the
   effect send entity.  The name does not have to be unique, but MUST be
   encapsulated into apostrophes and supports escape sequences as
   described in chapter "Character Set and Escape Sequences
   (Section 7.1)".

   Note: there are two possible approaches to apply audio effects with
   FX sends: you can either use a) internal effects or b) external
   effects.  By default, that is as initial routing, effect sends are
   automatically routed directly to the sampler channel's audio output
   device and the effect send's audio channels are by default
   automatically routed to the last audio channels of that audio output
   device (for the purpose of applying effects externally that is, e.g.
   by using another application), that way you can i.e. first increase
   the amount of audio channels on the audio output device for having
   dedicated effect send output channels and when "CREATE FX_SEND" is
   called, those channels will automatically be picked.  You can alter
   the destination channels however with "SET FX_SEND
   AUDIO_OUTPUT_CHANNEL" (Section 6.4.34).  If your intention is rather
   to use internal effects instead of external effects, then you first
   need to load those internal effects (Section 6.11) and then assign
   the FX sends to the desired internal effect by sending "SET FX_SEND
   EFFECT" (Section 6.4.35).

   Note: Create effect sends on a sampler channel only when needed,
   because having effect sends on a sampler channel will decrease
   runtime performance, because for implementing channel effect sends,


Schoenebeck            Expires September 12, 2019              [Page 66]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   separate (sampler channel local) audio buffers are needed to render
   and mix the voices and route the audio signal afterwards to the
   master outputs and effect send outputs (along with their respective
   effect send levels).  A sampler channel without effect sends however
   can mix its voices directly into the audio output devices's audio
   buffers and is thus faster.

   Possible Answers:

      "OK[<fx-send-id>]" -

         in case a new effect send could be added to the sampler
         channel, where <fx-send-id> reflects the unique ID of the newly
         created effect send entity

      "ERR:<error-code>:<error-message>" -

         when a new effect send could not be added, i.e.  due to invalid
         parameters

   Examples:

      C: "CREATE FX_SEND 0 91 'Reverb Send'"

      S: "OK[0]"

      C: "CREATE FX_SEND 0 93"

      S: "OK[1]"

6.4.29.  Removing an effect send from a sampler channel

   The front-end can remove an existing effect send on a specific
   sampler channel by sending the following command:

      DESTROY FX_SEND <sampler-channel> <fx-send-id>

   Where <sampler-channel> is the respective sampler channel number as
   returned by the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS"
   (Section 6.4.4) command, that is the sampler channel from which the
   effect send should be removed from and <fx-send-id> is the respective
   effect send number as returned by the "CREATE FX_SEND"
   (Section 6.4.28) or "LIST FX_SENDS" (Section 6.4.31) command.

   Possible Answers:

      "OK" -


Schoenebeck            Expires September 12, 2019              [Page 67]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         on success

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "DESTROY FX_SEND 0 0"

      S: "OK"

6.4.30.  Getting amount of effect sends on a sampler channel

   The front-end can ask for the amount of effect sends on a specific
   sampler channel by sending the following command:

      GET FX_SENDS <sampler-channel>

   Where <sampler-channel> is the respective sampler channel number as
   returned by the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS"
   (Section 6.4.4) command.

   Possible Answers:

      The sampler will answer by returning the number of effect sends on
      the given sampler channel.

   Example:

      C: "GET FX_SENDS 0"

      S: "2"

6.4.31.  Listing all effect sends on a sampler channel

   The front-end can ask for a list of effect sends on a specific
   sampler channel by sending the following command:

      LIST FX_SENDS <sampler-channel>

   Where <sampler-channel> is the respective sampler channel number as
   returned by the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS"
   (Section 6.4.4) command.

   Possible Answers:


Schoenebeck            Expires September 12, 2019              [Page 68]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      The sampler will answer by returning a comma separated list with
      all effect sends' numerical IDs on the given sampler channel.

   Examples:

      C: "LIST FX_SENDS 0"

      S: "0,1"

      C: "LIST FX_SENDS 1"

      S: ""

6.4.32.  Getting effect send information

   The front-end can ask for the current settings of an effect send
   entity by sending the following command:

      GET FX_SEND INFO <sampler-channel> <fx-send-id>

   Where <sampler-channel> is the sampler channel number as returned by
   the "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command and <fx-send-id> reflects the numerical ID of the effect send
   entity as returned by the "CREATE FX_SEND" (Section 6.4.28) or "LIST
   FX_SENDS" (Section 6.4.31) command.

   Possible Answers:

      The sampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the settings category name followed by a
      colon and then a space character <SP> and finally the info
      character string to that setting category.  At the moment the
      following categories are defined:


         NAME -

            name of the effect send entity (note that this character
            string may contain escape sequences (Section 7.1))

         MIDI_CONTROLLER -

            a value between 0 and 127 reflecting the MIDI controller
            which is able to modify the effect send's send level

         LEVEL -


Schoenebeck            Expires September 12, 2019              [Page 69]

Internet-Draft        LinuxSampler Control Protocol           March 2019


            optionally dotted number reflecting the effect send's
            current send level (where a value < 1.0 means attenuation
            and a value > 1.0 means amplification)

         AUDIO_OUTPUT_ROUTING -

            comma separated list which reflects to which audio channel
            of the selected audio output device each effect send output
            channel is routed to, e.g. "0,3" would mean the effect
            send's output channel 0 is routed to channel 0 of the audio
            output device and the effect send's output channel 1 is
            routed to the channel 3 of the audio output device (see "SET
            FX_SEND AUDIO_OUTPUT_CHANNEL" (Section 6.4.34) for details),
            if an internal send effect is assigned to the effect send,
            then this setting defines the audio channel routing to that
            effect instance respectively

         EFFECT -

            destination send effect chain ID and destination effect
            chain position, separated by comma in the form "<effect-
            chain>,<chain-pos>" or "NONE" if there is no send effect
            assigned to the effect send

   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET FX_SEND INFO 0 0"

      S: "NAME: Reverb Send"

      "MIDI_CONTROLLER: 91"

      "LEVEL: 0.3"

      "AUDIO_OUTPUT_ROUTING: 2,3"

      "EFFECT: NONE"

      "."

      C: "GET FX_SEND INFO 0 1"

      S: "NAME: Delay Send (Internal)"

      "MIDI_CONTROLLER: 93"


Schoenebeck            Expires September 12, 2019              [Page 70]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "LEVEL: 0.51"

      "AUDIO_OUTPUT_ROUTING: 1,2"

      "EFFECT: 2,0"

      "."

6.4.33.  Changing effect send's name

   The front-end can alter the current name of an effect send entity by
   sending the following command:

      SET FX_SEND NAME <sampler-chan> <fx-send-id> <name>

   Where <sampler-chan> is the sampler channel number as returned by the
   "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command, <fx-send-id> reflects the numerical ID of the effect send
   entity as returned by the "CREATE FX_SEND" (Section 6.4.28) or "LIST
   FX_SENDS" (Section 6.4.31) command and <name> is the new name of the
   effect send entity, which does not have to be unique (name MUST be
   encapsulated into apostrophes and supports escape sequences as
   described in chapter "Character Set and Escape Sequences
   (Section 7.1)").

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "SET FX_SEND NAME 0 0 'Fx Send 1'"

      S: "OK"

6.4.34.  Altering effect send's audio routing

   The front-end can alter the destination of an effect send's audio
   channel on a specific sampler channel by sending the following
   command:


Schoenebeck            Expires September 12, 2019              [Page 71]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      SET FX_SEND AUDIO_OUTPUT_CHANNEL <sampler-chan> <fx-send-id>
      <audio-src> <audio-dst>

   Where <sampler-chan> is the sampler channel number as returned by the
   "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command, <fx-send-id> reflects the numerical ID of the effect send
   entity as returned by the "CREATE FX_SEND" (Section 6.4.28) or "LIST
   FX_SENDS" (Section 6.4.31) command, <audio-src> is the numerical ID
   of the effect send's audio channel which should be rerouted and
   <audio-dst> is the numerical ID of either a) the audio output channel
   of the sampler channel's audio output device (i.e. if external effect
   shall be applied) or b) of the audio input channel of an internal
   effect assigned to the FX send where <audio-src> should be routed to.

   Note that effect sends can only route audio to the same audio output
   device as assigned to the effect send's sampler channel.  Also note
   that an effect send entity does always have exactly as much audio
   channels as its sampler channel.  So if the sampler channel is
   stereo, the effect send does have two audio channels as well.  Also
   keep in mind that the amount of audio channels on a sampler channel
   might be dependant not only to the deployed sampler engine on the
   sampler channel, but also dependant to the instrument currently
   loaded.  However you can (effectively) turn an i.e. stereo effect
   send into a mono one by simply altering its audio routing
   appropriately.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if audio output channel was set, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "SET FX_SEND AUDIO_OUTPUT_CHANNEL 0 0 0 2"

      S: "OK"


Schoenebeck            Expires September 12, 2019              [Page 72]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.4.35.  Assigning destination effect to an effect send

   The front-end can (re-)assign an internal destination effect to an
   effect send by sending the following command:

      SET FX_SEND EFFECT <sampler-chan> <fx-send-id> <effect-chain>
      <chain-pos>

   Where <sampler-chan> is the sampler channel number as returned by the
   "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command, <fx-send-id> reflects the numerical ID of the effect send
   entity as returned by the "CREATE FX_SEND" (Section 6.4.28) or "LIST
   FX_SENDS" (Section 6.4.31) command, <effect-chain> by the numerical
   ID of the destination effect chain as returned by the "ADD
   SEND_EFFECT_CHAIN" (Section 6.11.14) or "LIST SEND_EFFECT_CHAINS"
   (Section 6.11.13) command and <chain-pos> reflects the exact effect
   chain position in the effect chain which hosts the actual destination
   effect.

   Note: This command MUST NOT be used if you want to apply audio
   effects externally!  By default FX sends are routed directly to the
   audio output device for that purpose.  You can also revert this
   command later on by sending "REMOVE FX_SEND EFFECT" (Section 6.4.36),
   which will cause the FX send to be routed directly to the sampler
   channel's audio output device instead (i.e. for using external
   effects instead of internal effects).

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "SET FX_SEND EFFECT 0 0 2 5"

      S: "OK"


Schoenebeck            Expires September 12, 2019              [Page 73]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.4.36.  Removing destination effect from an effect send

   The front-end can (re-)assign a destination effect to an effect send
   by sending the following command:

      REMOVE FX_SEND EFFECT <sampler-chan> <fx-send-id>

   Where <sampler-chan> is the sampler channel number as returned by the
   "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command, <fx-send-id> reflects the numerical ID of the effect send
   entity as returned by the "CREATE FX_SEND" (Section 6.4.28) or "LIST
   FX_SENDS" (Section 6.4.31) command.

   After the destination effect has been removed from the effect send,
   the audio signal of the effect send will be routed directly to the
   audio output device, according to the audio channel routing setting
   of the effect send.

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "REMOVE FX_SEND EFFECT 0 0"

      S: "OK"

6.4.37.  Altering effect send's MIDI controller

   The front-end can alter the MIDI controller of an effect send entity
   by sending the following command:

      SET FX_SEND MIDI_CONTROLLER <sampler-chan> <fx-send-id> <midi-
      ctrl>

   Where <sampler-chan> is the sampler channel number as returned by the
   "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command, <fx-send-id> reflects the numerical ID of the effect send
   entity as returned by the "CREATE FX_SEND" (Section 6.4.28) or "LIST
   FX_SENDS" (Section 6.4.31) command and <midi-ctrl> reflects the MIDI


Schoenebeck            Expires September 12, 2019              [Page 74]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   controller which shall be able to modify the effect send's send
   level.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if MIDI controller was set, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "SET FX_SEND MIDI_CONTROLLER 0 0 91"

      S: "OK"

6.4.38.  Altering effect send's send level

   The front-end can alter the current send level of an effect send
   entity by sending the following command:

      SET FX_SEND LEVEL <sampler-chan> <fx-send-id> <volume>

   Where <sampler-chan> is the sampler channel number as returned by the
   "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command, <fx-send-id> reflects the numerical ID of the effect send
   entity as returned by the "CREATE FX_SEND" (Section 6.4.28) or "LIST
   FX_SENDS" (Section 6.4.31) command and <volume> is an optionally
   dotted positive number (a value smaller than 1.0 means attenuation,
   whereas a value greater than 1.0 means amplification) reflecting the
   new send level.

   Possible Answers:

      "OK" -

         on success


Schoenebeck            Expires September 12, 2019              [Page 75]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "WRN:<warning-code>:<warning-message>" -

         if new send level was set, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "SET FX_SEND LEVEL 0 0 0.15"

      S: "OK"

6.4.39.  Sending MIDI messages to sampler channel

   The front-end can send MIDI events to a specific sampler channel by
   sending the following command:

      SEND CHANNEL MIDI_DATA <midi-msg> <sampler-chan> <arg1> <arg2>

   Where <sampler-chan> is the sampler channel number as returned by the
   "ADD CHANNEL" (Section 6.4.5) or "LIST CHANNELS" (Section 6.4.4)
   command, <arg1> and <arg2> arguments depend on the <midi-msg>
   argument, which specifies the MIDI message type.  Currently, the
   following MIDI messages are supported:

      "NOTE_ON" -

         For turning on MIDI notes, where <arg1> specifies the key
         number and <arg2> the velocity as described in the MIDI
         specification.

      "NOTE_OFF" -

         For turning a currently playing MIDI note off, where <arg1>
         specifies the key number and <arg2> the velocity as described
         in the MIDI specification.

      "CC" -

         For changing a MIDI controller, where <arg1> specifies the
         controller number and <arg2> the new value of the controller as
         described in the Control Change section of the MIDI
         specification.


Schoenebeck            Expires September 12, 2019              [Page 76]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   CAUTION: This command is provided for implementations of virtual MIDI
   keyboards and no realtime guarantee whatsoever will be made!

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Example:

      C: "SEND CHANNEL MIDI_DATA NOTE_ON 0 56 112"

      S: "OK"

6.4.40.  Resetting a sampler channel

   The front-end can reset a particular sampler channel by sending the
   following command:

      RESET CHANNEL <sampler-channel>

   Where <sampler-channel> defines the sampler channel to be reset.
   This will cause the engine on that sampler channel, its voices and
   eventually disk streams and all control and status variables to be
   reset.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if channel was reset, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message


Schoenebeck            Expires September 12, 2019              [Page 77]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Examples:


6.5.  Controlling connection

   The following commands are used to control the connection to
   LinuxSampler.

6.5.1.  Register front-end for receiving event messages

   The front-end can register itself to the LinuxSampler application to
   be informed about noteworthy events by sending this command:

      SUBSCRIBE <event-id>

   where <event-id> will be replaced by the respective event that client
   wants to subscribe to.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if registration succeeded, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:


6.5.2.  Unregister front-end for not receiving event messages

   The front-end can unregister itself if it doesn't want to receive
   event messages anymore by sending the following command:

      UNSUBSCRIBE <event-id>


Schoenebeck            Expires September 12, 2019              [Page 78]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Where <event-id> will be replaced by the respective event that client
   doesn't want to receive anymore.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if unregistration succeeded, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:


6.5.3.  Enable or disable echo of commands

   To enable or disable back sending of commands to the client the
   following command can be used:

      SET ECHO <value>

   Where <value> should be replaced either by "1" to enable echo mode or
   "0" to disable echo mode.  When echo mode is enabled, all commands
   send to LinuxSampler will be immediately send back and after this
   echo the actual response to the command will be returned.  Echo mode
   will only be altered for the client connection that issued the "SET
   ECHO" command, not globally for all client connections.

   Possible Answers:

      "OK" -

         usually

      "ERR:<error-code>:<error-message>" -

         on syntax error, e.g. non boolean value


Schoenebeck            Expires September 12, 2019              [Page 79]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Examples:


6.5.4.  Close client connection

   The client can close its network connection to LinuxSampler by
   sending the following command:

      QUIT

   This is probably more interesting for manual telnet connections to
   LinuxSampler than really useful for a front-end implementation.

6.6.  Global commands

   The following commands have global impact on the sampler.

6.6.1.  Current number of active voices

   The front-end can ask for the current number of active voices on the
   sampler by sending the following command:

      GET TOTAL_VOICE_COUNT

   Possible Answers:

      LinuxSampler will answer by returning the number of all active
      voices on the sampler.

6.6.2.  Maximum amount of active voices

   The front-end can ask for the maximum number of active voices by
   sending the following command:

      GET TOTAL_VOICE_COUNT_MAX

   Possible Answers:

      LinuxSampler will answer by returning the maximum number of active
      voices.

6.6.3.  Current number of active disk streams

   The front-end can ask for the current number of active disk streams
   on the sampler by sending the following command:

      GET TOTAL_STREAM_COUNT


Schoenebeck            Expires September 12, 2019              [Page 80]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Possible Answers:

      LinuxSampler will answer by returning the number of all active
      disk streams on the sampler.

6.6.4.  Reset sampler

   The front-end can reset the whole sampler by sending the following
   command:

      RESET

   Possible Answers:

      "OK" -

         always

   Examples:


6.6.5.  General sampler information

   The client can ask for general information about the LinuxSampler
   instance by sending the following command:

      GET SERVER INFO

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that information category.  At the moment the
      following categories are defined:


         DESCRIPTION -

            arbitrary textual description about the sampler (note that
            the character string may contain escape sequences
            (Section 7.1))

         VERSION -

            version of the sampler


Schoenebeck            Expires September 12, 2019              [Page 81]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         PROTOCOL_VERSION -

            version of the LSCP specification the sampler complies with
            (see Section 2 for details)

         INSTRUMENTS_DB_SUPPORT -

            either yes or no, specifies whether the sampler is build
            with instruments database support.

   The mentioned fields above don't have to be in particular order.
   Other fields might be added in future.

   Example:

      C: "GET SERVER INFO"

      S: "DESCRIPTION: LinuxSampler - modular, streaming capable
      sampler"

      "VERSION: 1.0.0.svn23"

      "PROTOCOL_VERSION: 1.5"

      "INSTRUMENTS_DB_SUPPORT: no"

      "."

6.6.6.  Getting global volume attenuation

   The client can ask for the current global sampler-wide volume
   attenuation by sending the following command:

      GET VOLUME

   Possible Answers:

      The sampler will always answer by returning the optional dotted
      floating point coefficient, reflecting the current global volume
      attenuation.

   Note: it is up to the respective sampler engine whether to obey that
   global volume parameter or not, but in general all engines SHOULD use
   this parameter.


Schoenebeck            Expires September 12, 2019              [Page 82]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.6.7.  Setting global volume attenuation

   The client can alter the current global sampler-wide volume
   attenuation by sending the following command:

      SET VOLUME <volume>

   Where <volume> should be replaced by the optional dotted floating
   point value, reflecting the new global volume parameter.  This value
   might usually be in the range between 0.0 and 1.0, that is for
   attenuating the overall volume.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if the global volume was set, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

6.6.8.  Getting global voice limit

   The client can ask for the current global sampler-wide limit for
   maximum voices by sending the following command:

      GET VOICES

   Possible Answers:

      LinuxSampler will answer by returning the number for the current
      limit of maximum voices.

   The voice limit setting defines how many voices should maximum be
   processed by the sampler at the same time.  If the user triggers new
   notes which would exceed that voice limit, the sampler engine will
   react by stealing old voices for those newly triggered notes.  Note
   that the amount of voices triggered by a new note can be larger than
   one and is dependent to the respective instrument and probably
   further criterias.


Schoenebeck            Expires September 12, 2019              [Page 83]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.6.9.  Setting global voice limit

   The client can alter the current global sampler-wide limit for
   maximum voices by sending the following command:

      SET VOICES <max-voices>

   Where <max-voices> should be replaced by the integer value,
   reflecting the new global amount limit of maximum voices.  This value
   has to be larger than 0.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if the voice limit was set, but there are noteworthy issue(s)
         related, providing an appropriate warning code and warning
         message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Note: the given value will be passed to all sampler engine instances.
   The total amount of maximum voices on the running system might thus
   be as big as the given value multiplied by the current amount of
   engine instances.

   Caution: when adjusting the voice limit, you SHOULD also adjust the
   disk stream limit respectively and vice versa.

6.6.10.  Getting global disk stream limit

   The client can ask for the current global sampler-wide limit for
   maximum disk streams by sending the following command:

      GET STREAMS

   Possible Answers:

      LinuxSampler will answer by returning the number for the current
      limit of maximum disk streams.


Schoenebeck            Expires September 12, 2019              [Page 84]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   The disk stream limit setting defines how many disk streams should
   maximum be processed by a sampler engine at the same time.  The
   higher this value, the more memory (RAM) will be occupied, since
   every disk streams allocates a certain buffer size for being able to
   perform its streaming operations.

6.6.11.  Setting global disk stream limit

   The client can alter the current global sampler-wide limit for
   maximum disk streams by sending the following command:

      SET STREAMS <max-streams>

   Where <max-streams> should be replaced by the integer value,
   reflecting the new global amount limit of maximum disk streams.  This
   value has to be positive.

   Possible Answers:

      "OK" -

         on success

      "WRN:<warning-code>:<warning-message>" -

         if the disk stream limit was set, but there are noteworthy
         issue(s) related, providing an appropriate warning code and
         warning message

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Note: the given value will be passed to all sampler engine instances.
   The total amount of maximum disk streams on the running system might
   thus be as big as the given value multiplied by the current amount of
   engine instances.

   Caution: when adjusting the disk stream limit, you SHOULD also adjust
   the voice limit respectively and vice versa.

6.7.  MIDI Instrument Mapping

   The MIDI protocol provides a way to switch between instruments by
   sending so called MIDI bank select and MIDI program change messages
   which are essentially just numbers.  The following commands allow to


Schoenebeck            Expires September 12, 2019              [Page 85]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   actually map arbitrary MIDI bank select / program change numbers with
   real instruments.

   The sampler allows to manage an arbitrary amount of MIDI instrument
   maps which define which instrument to load on which MIDI program
   change message.

   By default, that is when the sampler is launched, there is no map,
   thus the sampler will simply ignore all program change messages.  The
   front-end has to explicitly create at least one map, add entries to
   the map and tell the respective sampler channel(s) which MIDI
   instrument map to use, so the sampler knows how to react on a given
   program change message on the respective sampler channel, that is by
   switching to the respectively defined engine type and loading the
   respective instrument.  See command "SET CHANNEL MIDI_INSTRUMENT_MAP"
   (Section 6.4.27) for how to assign a MIDI instrument map to a sampler
   channel.

   Also note per MIDI specification a bank select message does not cause
   to switch to another instrument.  Instead when receiving a bank
   select message the bank value will be stored and a subsequent program
   change message (which may occur at any time) will finally cause the
   sampler to switch to the respective instrument as reflected by the
   current MIDI instrument map.

6.7.1.  Create a new MIDI instrument map

   The front-end can add a new MIDI instrument map by sending the
   following command:

      ADD MIDI_INSTRUMENT_MAP [<name>]

   Where <name> is an optional argument allowing to assign a custom name
   to the new map.  MIDI instrument Map names do not have to be unique,
   but MUST be encapsulated into apostrophes and support escape
   sequences as described in chapter "Character Set and Escape Sequences
   (Section 7.1)".

   Possible Answers:

      "OK[<map>]" -

         in case a new MIDI instrument map could be added, where <map>
         reflects the unique ID of the newly created MIDI instrument map

      "ERR:<error-code>:<error-message>" -


Schoenebeck            Expires September 12, 2019              [Page 86]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         when a new map could not be created, which might never occur in
         practice

   Examples:

      C: "ADD MIDI_INSTRUMENT_MAP 'Standard Map'"

      S: "OK[0]"

      C: "ADD MIDI_INSTRUMENT_MAP 'Standard Drumkit'"

      S: "OK[1]"

      C: "ADD MIDI_INSTRUMENT_MAP"

      S: "OK[5]"

6.7.2.  Delete one particular or all MIDI instrument maps

   The front-end can delete a particular MIDI instrument map by sending
   the following command:

      REMOVE MIDI_INSTRUMENT_MAP <map>

   Where <map> reflects the unique ID of the map to delete as returned
   by the "LIST MIDI_INSTRUMENT_MAPS" (Section 6.7.4) command.

   The front-end can delete all MIDI instrument maps by sending the
   following command:

      REMOVE MIDI_INSTRUMENT_MAP ALL

   Possible Answers:

      "OK" -

         in case the map(s) could be deleted

      "ERR:<error-code>:<error-message>" -

         when the given map does not exist

   Examples:

      C: "REMOVE MIDI_INSTRUMENT_MAP 0"

      S: "OK"


Schoenebeck            Expires September 12, 2019              [Page 87]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      C: "REMOVE MIDI_INSTRUMENT_MAP ALL"

      S: "OK"

6.7.3.  Get amount of existing MIDI instrument maps

   The front-end can retrieve the current amount of MIDI instrument maps
   by sending the following command:

      GET MIDI_INSTRUMENT_MAPS

   Possible Answers:

      The sampler will answer by returning the current number of MIDI
      instrument maps.

   Example:

      C: "GET MIDI_INSTRUMENT_MAPS"

      S: "2"

6.7.4.  Getting all created MIDI instrument maps

   The number of MIDI instrument maps can change on runtime.  To get the
   current list of MIDI instrument maps, the front-end can send the
   following command:

      LIST MIDI_INSTRUMENT_MAPS

   Possible Answers:

      The sampler will answer by returning a comma separated list with
      all MIDI instrument maps' numerical IDs.

   Example:

      C: "LIST MIDI_INSTRUMENT_MAPS"

      S: "0,1,5,12"

6.7.5.  Getting MIDI instrument map information

   The front-end can ask for the current settings of a MIDI instrument
   map by sending the following command:

      GET MIDI_INSTRUMENT_MAP INFO <map>


Schoenebeck            Expires September 12, 2019              [Page 88]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Where <map> is the numerical ID of the map the front-end is
   interested in as returned by the "LIST MIDI_INSTRUMENT_MAPS"
   (Section 6.7.4) command.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the settings category name followed by a
      colon and then a space character <SP> and finally the info
      character string to that setting category.  At the moment the
      following categories are defined:


         NAME -

            custom name of the given map, which does not have to be
            unique (note that this character string may contain escape
            sequences (Section 7.1))

         DEFAULT -

            either true or false, defines whether this map is the
            default map

   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET MIDI_INSTRUMENT_MAP INFO 0"

      S: "NAME: Standard Map"

      "DEFAULT: true"

      "."

6.7.6.  Renaming a MIDI instrument map

   The front-end can alter the custom name of a MIDI instrument map by
   sending the following command:

      SET MIDI_INSTRUMENT_MAP NAME <map> <name>

   Where <map> is the numerical ID of the map and <name> the new custom
   name of the map, which does not have to be unique (name MUST be
   encapsulated into apostrophes and supports escape sequences as


Schoenebeck            Expires September 12, 2019              [Page 89]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   described in chapter "Character Set and Escape Sequences
   (Section 7.1)").

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case the given map does not exist

   Example:

      C: "SET MIDI_INSTRUMENT_MAP NAME 0 'Foo instruments'"

      S: "OK"

6.7.7.  Create or replace a MIDI instrument map entry

   The front-end can create a new or replace an existing entry in a
   sampler's MIDI instrument map by sending the following command:

      MAP MIDI_INSTRUMENT [NON_MODAL] <map> <midi_bank> <midi_prog>
      <engine_name> <filename> <instrument_index> <volume_value>
      [<instr_load_mode>] [<name>]

   Where <map> is the numeric ID of the map to alter, <midi_bank> is an
   integer value between 0..16383 reflecting the MIDI bank select index,
   <midi_prog> an integer value between 0..127 reflecting the MIDI
   program change index, <engine_name> a sampler engine name as returned
   by the "LIST AVAILABLE_ENGINES" (Section 6.4.8) command (not
   encapsulated into apostrophes), <filename> the name of the
   instrument's file to be deployed (encapsulated into apostrophes,
   supporting escape sequences as described in chapter "Character Set
   and Escape Sequences (Section 7.1)"), <instrument_index> the index
   (integer value) of the instrument within the given file,
   <volume_value> reflects the master volume of the instrument as
   optionally dotted number (where a value < 1.0 means attenuation and a
   value > 1.0 means amplification).  This parameter easily allows to
   adjust the volume of all intruments within a custom instrument map
   without having to adjust their instrument files.  The OPTIONAL
   <instr_load_mode> argument defines the life time of the instrument,
   that is when the instrument should be loaded, when freed and has
   exactly the following possibilities:

      "ON_DEMAND" -


Schoenebeck            Expires September 12, 2019              [Page 90]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         The instrument will be loaded when needed, that is when
         demanded by at least one sampler channel.  It will immediately
         be freed from memory when not needed by any sampler channel
         anymore.

      "ON_DEMAND_HOLD" -

         The instrument will be loaded when needed, that is when
         demanded by at least one sampler channel.  It will be kept in
         memory even when not needed by any sampler channel anymore.
         Instruments with this mode are only freed when the sampler is
         reset or all mapping entries with this mode (and respective
         instrument) are explicitly changed to "ON_DEMAND" and no
         sampler channel is using the instrument anymore.

      "PERSISTENT" -

         The instrument will immediately be loaded into memory when this
         mapping command is sent and the instrument is kept all the
         time.  Instruments with this mode are only freed when the
         sampler is reset or all mapping entries with this mode (and
         respective instrument) are explicitly changed to "ON_DEMAND"
         and no sampler channel is using the instrument anymore.

      not supplied -

         In case there is no <instr_load_mode> argument given, it will
         be up to the InstrumentManager to decide which mode to use.
         Usually it will use "ON_DEMAND" if an entry for the given
         instrument does not exist in the InstrumentManager's list yet,
         otherwise if an entry already exists, it will simply stick with
         the mode currently reflected by the already existing entry,
         that is it will not change the mode.

   The <instr_load_mode> argument thus allows to define an appropriate
   strategy (low memory consumption vs. fast instrument switching) for
   each instrument individually.  Note, the following restrictions apply
   to this argument: "ON_DEMAND_HOLD" and "PERSISTENT" have to be
   supported by the respective sampler engine (which is technically the
   case when the engine provides an InstrumentManager for its format).
   If this is not the case the argument will automatically fall back to
   the default value "ON_DEMAND".  Also the load mode of one instrument
   may automatically change the laod mode of other instrument(s), i.e.
   because the instruments are part of the same file and the engine does
   not allow a way to manage load modes for them individually.  Due to
   this, in case the frontend shows the load modes of entries, the
   frontend should retrieve the actual mode by i.e. sending "GET
   MIDI_INSTRUMENT INFO" (Section 6.7.11) command(s).  Finally the


Schoenebeck            Expires September 12, 2019              [Page 91]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   OPTIONAL <name> argument allows to set a custom name (encapsulated
   into apostrophes, supporting escape sequences as described in chapter
   "Character Set and Escape Sequences (Section 7.1)") for the mapping
   entry, useful for frontends for displaying an appropriate name for
   mapped instruments (using "GET MIDI_INSTRUMENT INFO"
   (Section 6.7.11)).

   By default, "MAP MIDI_INSTRUMENT" commands block until the mapping is
   completely established in the sampler.  The OPTIONAL "NON_MODAL"
   argument however causes the respective "MAP MIDI_INSTRUMENT" command
   to return immediately, that is to let the sampler establish the
   mapping in the background.  So this argument might be especially
   useful for mappings with a "PERSISTENT" type, because these have to
   load the respective instruments immediately and might thus block for
   a very long time.  It is recommended however to use the OPTIONAL
   "NON_MODAL" argument only if really necessary, because it has the
   following drawbacks: as "NON_MODAL" instructions return immediately,
   they may not necessarily return an error i.e. when the given
   instrument file turns out to be corrupt, beside that subsequent
   commands in a LSCP instruction sequence might fail, because mandatory
   mappings are not yet completed.

   Possible Answers:

      "OK" -

         usually

      "ERR:<error-code>:<error-message>" -

         when the given map or engine does not exist or a value is out
         of range

   Examples:

      C: "MAP MIDI_INSTRUMENT 0 3 0 gig '/usr/share/Steinway D.gig' 0
      0.8 PERSISTENT"

      S: "OK"

      C: "MAP MIDI_INSTRUMENT 0 4 50 gig '/home/john/foostrings.gig' 7
      1.0"

      S: "OK"

      C: "MAP MIDI_INSTRUMENT 0 0 0 gig '/usr/share/piano.gig' 0 1.0
      'Normal Piano'"


Schoenebeck            Expires September 12, 2019              [Page 92]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      S: "OK"

      C: "MAP MIDI_INSTRUMENT 0 1 0 gig '/usr/share/piano.gig' 0 0.25
      'Silent Piano'"

      S: "OK"

      C: "MAP MIDI_INSTRUMENT NON_MODAL 1 8 120 gig '/home/joe/
      foodrums.gig' 0 1.0 PERSISTENT 'Foo Drumkit'"

      S: "OK"

6.7.8.  Getting amount of MIDI instrument map entries

   The front-end can query the amount of currently existing entries in a
   MIDI instrument map by sending the following command:

      GET MIDI_INSTRUMENTS <map>

   The front-end can query the amount of currently existing entries in
   all MIDI instrument maps by sending the following command:

      GET MIDI_INSTRUMENTS ALL

   Possible Answers:

      The sampler will answer by sending the current number of entries
      in the MIDI instrument map(s).

   Example:

      C: "GET MIDI_INSTRUMENTS 0"

      S: "234"

      C: "GET MIDI_INSTRUMENTS ALL"

      S: "954"

6.7.9.  Getting indeces of all entries of a MIDI instrument map

   The front-end can query a list of all currently existing entries in a
   certain MIDI instrument map by sending the following command:

      LIST MIDI_INSTRUMENTS <map>

   Where <map> is the numeric ID of the MIDI instrument map.


Schoenebeck            Expires September 12, 2019              [Page 93]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   The front-end can query a list of all currently existing entries of
   all MIDI instrument maps by sending the following command:

      LIST MIDI_INSTRUMENTS ALL

   Possible Answers:

      The sampler will answer by sending a comma separated list of map
      ID - MIDI bank - MIDI program triples, where each triple is
      encapsulated into curly braces.  The list is returned in one
      single line.  Each triple just reflects the key of the respective
      map entry, thus subsequent "GET MIDI_INSTRUMENT INFO"
      (Section 6.7.11) command(s) are necessary to retrieve detailed
      information about each entry.

   Example:

      C: "LIST MIDI_INSTRUMENTS 0"

      S: "{0,0,0},{0,0,1},{0,0,3},{0,1,4},{1,127,127}"

6.7.10.  Remove an entry from the MIDI instrument map

   The front-end can delete an entry from a MIDI instrument map by
   sending the following command:

      UNMAP MIDI_INSTRUMENT <map> <midi_bank> <midi_prog>

   Where <map> is the numeric ID of the MIDI instrument map, <midi_bank>
   is an integer value between 0..16383 reflecting the MIDI bank value
   and <midi_prog> an integer value between 0..127 reflecting the MIDI
   program value of the map's entrie's key index triple.

   Possible Answers:

      "OK" -

         usually

      "ERR:<error-code>:<error-message>" -

         when index out of bounds

   Example:

      C: "UNMAP MIDI_INSTRUMENT 0 2 127"

      S: "OK"


Schoenebeck            Expires September 12, 2019              [Page 94]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.7.11.  Get current settings of MIDI instrument map entry

   The front-end can retrieve the current settings of a certain
   instrument map entry by sending the following command:

      GET MIDI_INSTRUMENT INFO <map> <midi_bank> <midi_prog>

   Where <map> is the numeric ID of the MIDI instrument map, <midi_bank>
   is an integer value between 0..16383 reflecting the MIDI bank value,
   <midi_bank> and <midi_prog> an integer value between 0..127
   reflecting the MIDI program value of the map's entrie's key index
   triple.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name followed by
      a colon and then a space character <SP> and finally the info
      character string to that info category.  At the moment the
      following categories are defined:

      "NAME" -

         Name for this MIDI instrument map entry (if defined).  This
         name shall be used by frontends for displaying a name for this
         mapped instrument.  It can be set and changed with the "MAP
         MIDI_INSTRUMENT" (Section 6.7.7) command and does not have to
         be unique.  (note that this character string may contain escape
         sequences (Section 7.1))

      "ENGINE_NAME" -

         Name of the engine to be deployed for this instrument.

      "INSTRUMENT_FILE" -

         File name of the instrument (note that this path may contain
         escape sequences (Section 7.1)).

      "INSTRUMENT_NR" -

         Index of the instrument within the file.

      "INSTRUMENT_NAME" -

         Name of the loaded instrument as reflected by its file.  In
         contrast to the "NAME" field, the "INSTRUMENT_NAME" field


Schoenebeck            Expires September 12, 2019              [Page 95]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         cannot be changed (note that this character string may contain
         escape sequences (Section 7.1)).

      "LOAD_MODE" -

         Life time of instrument (see "MAP MIDI_INSTRUMENT"
         (Section 6.7.7) for details about this setting).

      "VOLUME" -

         master volume of the instrument as optionally dotted number
         (where a value < 1.0 means attenuation and a value > 1.0 means
         amplification)

      The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET MIDI_INSTRUMENT INFO 1 45 120"

      S: "NAME: Drums for Foo Song"

      "ENGINE_NAME: GigEngine"

      "INSTRUMENT_FILE: /usr/share/joesdrumkit.gig"

      "INSTRUMENT_NR: 0"

      "INSTRUMENT_NAME: Joe's Drumkit"

      "LOAD_MODE: PERSISTENT"

      "VOLUME: 1.0"

      "."

6.7.12.  Clear MIDI instrument map

   The front-end can clear a whole MIDI instrument map, that is delete
   all its entries by sending the following command:

      CLEAR MIDI_INSTRUMENTS <map>

   Where <map> is the numeric ID of the map to clear.

   The front-end can clear all MIDI instrument maps, that is delete all
   entries of all maps by sending the following command:


Schoenebeck            Expires September 12, 2019              [Page 96]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      CLEAR MIDI_INSTRUMENTS ALL

   The command "CLEAR MIDI_INSTRUMENTS ALL" does not delete the maps,
   only their entries, thus the map's settings like custom name will be
   preservevd.

   Possible Answers:

      "OK" -

         always

   Examples:

      C: "CLEAR MIDI_INSTRUMENTS 0"

      S: "OK"

      C: "CLEAR MIDI_INSTRUMENTS ALL"

      S: "OK"

6.8.  Managing Instruments Database

   The following commands describe how to use and manage the instruments
   database.

   Notice:

      All command arguments representing a path or instrument/directory
      name support escape sequences as described in chapter "Character
      Set and Escape Sequences (Section 7.1)".

      All occurrences of a forward slash in instrument and directory
      names are escaped with its hex (\x2f) or octal (\057) escape
      sequence.

6.8.1.  Creating a new instrument directory

   The front-end can add a new instrument directory to the instruments
   database by sending the following command:

      ADD DB_INSTRUMENT_DIRECTORY <dir>

   Where <dir> is the absolute path name of the directory to be created
   (encapsulated into apostrophes).

   Possible Answers:


Schoenebeck            Expires September 12, 2019              [Page 97]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         when the directory could not be created, which can happen if
         the directory already exists or the name contains not allowed
         symbols

   Examples:

      C: "ADD DB_INSTRUMENT_DIRECTORY '/Piano Collection'"

      S: "OK"

6.8.2.  Deleting an instrument directory

   The front-end can delete a particular instrument directory from the
   instruments database by sending the following command:

      REMOVE DB_INSTRUMENT_DIRECTORY [FORCE] <dir>

   Where <dir> is the absolute path name of the directory to delete.
   The optional FORCE argument can be used to force the deletion of a
   non-empty directory and all its content.

   Possible Answers:

      "OK" -

         if the directory is deleted successfully

      "ERR:<error-code>:<error-message>" -

         if the given directory does not exist, or if trying to delete a
         non-empty directory, without using the FORCE argument.

   Examples:

      C: "REMOVE DB_INSTRUMENT_DIRECTORY FORCE '/Piano Collection'"

      S: "OK"


Schoenebeck            Expires September 12, 2019              [Page 98]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.8.3.  Getting amount of instrument directories

   The front-end can retrieve the current amount of directories in a
   specific directory by sending the following command:

      GET DB_INSTRUMENT_DIRECTORIES [RECURSIVE] <dir>

   Where <dir> should be replaced by the absolute path name of the
   directory.  If RECURSIVE is specified, the number of all directories,
   including those located in subdirectories of the specified directory,
   will be returned.

   Possible Answers:

      The current number of instrument directories in the specified
      directory.

      "ERR:<error-code>:<error-message>" -

         if the given directory does not exist.

   Example:

      C: "GET DB_INSTRUMENT_DIRECTORIES '/'"

      S: "2"

6.8.4.  Listing all directories in specific directory

   The front-end can retrieve the current list of directories in
   specific directory by sending the following command:

      LIST DB_INSTRUMENT_DIRECTORIES [RECURSIVE] <dir>

   Where <dir> should be replaced by the absolute path name of the
   directory.  If RECURSIVE is specified, the absolute path names of all
   directories, including those located in subdirectories of the
   specified directory, will be returned.

   Possible Answers:

      A comma separated list of all instrument directories (encapsulated
      into apostrophes) in the specified directory.

      "ERR:<error-code>:<error-message>" -

         if the given directory does not exist.


Schoenebeck            Expires September 12, 2019              [Page 99]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Example:

      C: "LIST DB_INSTRUMENT_DIRECTORIES '/'"

      S: "'Piano Collection','Percussion Collection'"

      C: "LIST DB_INSTRUMENT_DIRECTORIES RECURSIVE '/'"

      S: "'/Piano Collection','/Piano Collection/Acoustic','/Piano
      Collection/Acoustic/New','/Percussion Collection'"

6.8.5.  Getting instrument directory information

   The front-end can ask for the current settings of an instrument
   directory by sending the following command:

      GET DB_INSTRUMENT_DIRECTORY INFO <dir>

   Where <dir> should be replaced by the absolute path name of the
   directory the front-end is interested in.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the settings category name followed by a
      colon and then a space character <SP> and finally the info
      character string to that setting category.  At the moment the
      following categories are defined:


         DESCRIPTION -

            A brief description of the directory content.  Note that the
            character string may contain escape sequences (Section 7.1).

         CREATED -

            The creation date and time of the directory, represented in
            "YYYY-MM-DD HH:MM:SS" format

         MODIFIED -

            The date and time of the last modification of the directory,
            represented in "YYYY-MM-DD HH:MM:SS" format

   The mentioned fields above don't have to be in particular order.


Schoenebeck            Expires September 12, 2019             [Page 100]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Example:

      C: "GET DB_INSTRUMENT_DIRECTORY INFO '/Piano Collection'"

      S: "DESCRIPTION: Piano collection of instruments in GigaSampler
      format."

      "CREATED: 2007-02-05 10:23:12"

      "MODIFIED: 2007-04-07 12:50:21"

      "."

6.8.6.  Renaming an instrument directory

   The front-end can alter the name of a specific instrument directory
   by sending the following command:

      SET DB_INSTRUMENT_DIRECTORY NAME <dir> <name>

   Where <dir> is the absolute path name of the directory and <name> is
   the new name for that directory.

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case the given directory does not exists, or if a directory
         with name equal to the new name already exists.

   Example:

      C: "SET DB_INSTRUMENT_DIRECTORY NAME '/Piano Collection/Acustic'
      'Acoustic'"

      S: "OK"

6.8.7.  Moving an instrument directory

   The front-end can move a specific instrument directory by sending the
   following command:

      MOVE DB_INSTRUMENT_DIRECTORY <dir> <dst>


Schoenebeck            Expires September 12, 2019             [Page 101]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Where <dir> is the absolute path name of the directory to move and
   <dst> is the location where the directory will be moved to.

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case a given directory does not exists, or if a directory
         with name equal to the name of the specified directory already
         exists in the destination directory.  Error is also thrown when
         trying to move a directory to a subdirectory of itself.

   Example:

      C: "MOVE DB_INSTRUMENT_DIRECTORY '/Acoustic' '/Piano Collection/
      Acoustic'"

      S: "OK"

6.8.8.  Copying instrument directories

   The front-end can copy a specific instrument directory by sending the
   following command:

      COPY DB_INSTRUMENT_DIRECTORY <dir> <dst>

   Where <dir> is the absolute path name of the directory to copy and
   <dst> is the location where the directory will be copied to.

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case a given directory does not exists, or if a directory
         with name equal to the name of the specified directory already
         exists in the destination directory.  Error is also thrown when
         trying to copy a directory to a subdirectory of itself.

   Example:


Schoenebeck            Expires September 12, 2019             [Page 102]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      C: "COPY DB_INSTRUMENT_DIRECTORY '/Piano Collection/Acoustic'
      '/Acoustic/Pianos'"

      S: "OK"

6.8.9.  Changing the description of directory

   The front-end can alter the description of a specific instrument
   directory by sending the following command:

      SET DB_INSTRUMENT_DIRECTORY DESCRIPTION <dir> <desc>

   Where <dir> is the absolute path name of the directory and <desc> is
   the new description for the directory (encapsulated into apostrophes,
   supporting escape sequences as described in chapter "Character Set
   and Escape Sequences (Section 7.1)").

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case the given directory does not exists.

   Example:

      C: "SET DB_INSTRUMENT_DIRECTORY DESCRIPTION '/Piano Collection' 'A
      collection of piano instruments in various format.'"

      S: "OK"

6.8.10.  Finding directories

   The front-end can search for directories in specific directory by
   sending the following command:

      FIND DB_INSTRUMENT_DIRECTORIES [NON_RECURSIVE] <dir> <criteria-
      list>

   Where <dir> should be replaced by the absolute path name of the
   directory to search in.  If NON_RECURSIVE is specified, the
   directories located in subdirectories of the specified directory will
   not be searched. <criteria-list> is a list of search criterias in
   form of "key1=val1 key2=val2 ...".  The following criterias are
   allowed:


Schoenebeck            Expires September 12, 2019             [Page 103]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Where <search-string> is either a regular expression, or a word list
   separated with spaces for OR search and with '+' for AND search.

   Possible Answers:

      A comma separated list with the absolute path names (encapsulated
      into apostrophes) of all directories in the specified directory
      that satisfy the supplied search criterias.

      "ERR:<error-code>:<error-message>" -

         if the given directory does not exist.

   Example:

      C: "FIND DB_INSTRUMENT_DIRECTORIES '/' NAME='Piano'"

      S: "'/Piano Collection'"

      C: "FIND DB_INSTRUMENT_DIRECTORIES '/' CREATED='..2007-04-01
      09:30:13'"

      S: "'/Piano Collection','/Percussions'"

6.8.11.  Adding instruments to the instruments database

   The front-end can add one or more instruments to the instruments
   database by sending the following command:

      ADD DB_INSTRUMENTS [NON_MODAL] [<mode>[ FILE_AS_DIR]] <db_dir>
      <file_path> [<instr_index>]

   Where <db_dir> is the absolute path name of a directory (encapsulated
   into apostrophes) in the instruments database in which only the new
   instruments (that are not already in the database) will be added,
   <file_path> is the absolute path name of a file or directory in the
   file system (encapsulated into apostrophes).  In case an instrument
   file is supplied, only the instruments in the specified file will be
   added to the instruments database.  If the optional <instr_index>
   (the index of the instrument within the given file) is supplied too,
   then only the specified instrument will be added.  In case a
   directory is supplied, the instruments in that directory will be
   added.  The OPTIONAL <mode> argument is only applied when a directory
   is provided as <file_path> and specifies how the scanning will be
   done and has exactly the following possibilities:

      "RECURSIVE" -


Schoenebeck            Expires September 12, 2019             [Page 104]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         All instruments will be processed, including those in the
         subdirectories, and the respective subdirectory tree structure
         will be recreated in the instruments database

      "NON_RECURSIVE" -

         Only the instruments in the specified directory will be added,
         the instruments in the subdirectories will not be processed.

      "FLAT" -

         All instruments will be processed, including those in the
         subdirectories, but the respective subdirectory structure will
         not be recreated in the instruments database.  All instruments
         will be added directly in the specified database directory.

   If FILE_AS_DIR argument is supplied, all instruments in an instrument
   file will be added to a separate directory in the instruments
   database, which name will be the name of the instrument file with the
   file extension stripped off.

   The difference between regular and NON_MODAL versions of the command
   is that the regular command returns when the scanning is finished
   while NON_MODAL version returns immediately and a background process
   is launched.  The GET DB_INSTRUMENTS_JOB INFO (Section 6.8.21)
   command can be used to monitor the scanning progress.

   Possible Answers:

      "OK" -

         on success when NON_MODAL is not supplied

      "OK[<job-id>]" -

         on success when NON_MODAL is supplied, where <job-id> is a
         numerical ID used to obtain status information about the job
         progress.  See GET DB_INSTRUMENTS_JOB INFO (Section 6.8.21)

      "ERR:<error-code>:<error-message>" -

         if an invalid path is specified.

   Examples:

      C: "ADD DB_INSTRUMENTS '/Piano Collection' '/home/me/gigs/PMI
      Bosendorfer 290.gig' 0"


Schoenebeck            Expires September 12, 2019             [Page 105]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      S: "OK"

6.8.12.  Removing an instrument

   The front-end can remove a particular instrument from the instruments
   database by sending the following command:

      REMOVE DB_INSTRUMENT <instr_path>

   Where <instr_path> is the absolute path name (in the instruments
   database) of the instrument to remove.

   Possible Answers:

      "OK" -

         if the instrument is removed successfully

      "ERR:<error-code>:<error-message>" -

         if the given path does not exist or is a directory.

   Examples:

      C: "REMOVE DB_INSTRUMENT '/Piano Collection/Bosendorfer 290'"

      S: "OK"

6.8.13.  Getting amount of instruments

   The front-end can retrieve the current amount of instruments in a
   specific directory by sending the following command:

      GET DB_INSTRUMENTS [RECURSIVE] <dir>

   Where <dir> should be replaced by the absolute path name of the
   directory.  If RECURSIVE is specified, the number of all instruments,
   including those located in subdirectories of the specified directory,
   will be returned.

   Possible Answers:

      The current number of instruments in the specified directory.

      "ERR:<error-code>:<error-message>" -

         if the given directory does not exist.


Schoenebeck            Expires September 12, 2019             [Page 106]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Example:

      C: "GET DB_INSTRUMENTS '/Piano Collection'"

      S: "2"

6.8.14.  Listing all instruments in specific directory

   The front-end can retrieve the current list of instruments in
   specific directory by sending the following command:

      LIST DB_INSTRUMENTS [RECURSIVE] <dir>

   Where <dir> should be replaced by the absolute path name of the
   directory.  If RECURSIVE is specified, the absolute path names of all
   instruments, including those located in subdirectories of the
   specified directory, will be returned.

   Possible Answers:

      A comma separated list of all instruments (encapsulated into
      apostrophes) in the specified directory.

      "ERR:<error-code>:<error-message>" -

         if the given directory does not exist.

   Example:

      C: "LIST DB_INSTRUMENTS '/Piano Collection'"

      S: "'Bosendorfer 290','Steinway D'"

      C: "LIST DB_INSTRUMENTS RECURSIVE '/Piano Collection'"

      S: "'/Piano Collection/Bosendorfer 290','/Piano Collection/
      Steinway D','/Piano Collection/Lite/Free Piano'"

6.8.15.  Getting instrument information

   The front-end can ask for the current settings of an instrument by
   sending the following command:

      GET DB_INSTRUMENT INFO <instr_path>

   Where <instr_path> should be replaced by the absolute path name of
   the instrument the front-end is interested in.


Schoenebeck            Expires September 12, 2019             [Page 107]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the settings category name followed by a
      colon and then a space character <SP> and finally the info
      character string to that setting category.  At the moment the
      following categories are defined:


         INSTRUMENT_FILE -

            File name of the instrument.  Note that the character string
            may contain escape sequences (Section 7.1).

         INSTRUMENT_NR -

            Index of the instrument within the file.

         FORMAT_FAMILY -

            The format family of the instrument.

         FORMAT_VERSION -

            The format version of the instrument.

         SIZE -

            The size of the instrument in bytes.

         CREATED -

            The date and time when the instrument is added in the
            instruments database, represented in "YYYY-MM-DD HH:MM:SS"
            format

         MODIFIED -

            The date and time of the last modification of the
            instrument's database settings, represented in "YYYY-MM-DD
            HH:MM:SS" format

         DESCRIPTION -

            A brief description of the instrument.  Note that the
            character string may contain escape sequences (Section 7.1).


Schoenebeck            Expires September 12, 2019             [Page 108]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         IS_DRUM -

            either true or false, determines whether the instrument is a
            drumkit or a chromatic instrument

         PRODUCT -

            The product title of the instrument.  Note that the
            character string may contain escape sequences (Section 7.1).

         ARTISTS -

            Lists the artist names.  Note that the character string may
            contain escape sequences (Section 7.1).

         KEYWORDS -

            Provides a list of keywords that refer to the instrument.
            Keywords are separated with semicolon and blank.  Note that
            the character string may contain escape sequences
            (Section 7.1).

   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET DB_INSTRUMENT INFO '/Piano Collection/Bosendorfer 290'"

      S: "INSTRUMENT_FILE: /home/me/gigs/Bosendorfer 290.gig"

      "INSTRUMENT_NR: 0"

      "FORMAT_FAMILY: GIG"

      "FORMAT_VERSION: 2"

      "SIZE: 2050871870"

      "CREATED: 2007-02-05 10:23:12"

      "MODIFIED: 2007-04-07 12:50:21"

      "DESCRIPTION: "

      "IS_DRUM: false"

      "PRODUCT: GRANDIOSO Bosendorfer 290"


Schoenebeck            Expires September 12, 2019             [Page 109]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "ARTISTS: Post Musical Instruments"

      "KEYWORDS: Bosendorfer"

      "."

6.8.16.  Renaming an instrument

   The front-end can alter the name of a specific instrument by sending
   the following command:

      SET DB_INSTRUMENT NAME <instr> <name>

   Where <instr> is the absolute path name of the instrument and <name>
   is the new name for that instrument.

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case the given instrument does not exists, or if an
         instrument with name equal to the new name already exists.

   Example:

      C: "SET DB_INSTRUMENT NAME '/Piano Collection/Bosendorfer'
      'Bosendorfer 290'"

      S: "OK"

6.8.17.  Moving an instrument

   The front-end can move a specific instrument to another directory by
   sending the following command:

      MOVE DB_INSTRUMENT <instr> <dst>

   Where <instr> is the absolute path name of the instrument to move and
   <dst> is the directory where the instrument will be moved to.

   Possible Answers:

      "OK" -


Schoenebeck            Expires September 12, 2019             [Page 110]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         on success

      "ERR:<error-code>:<error-message>" -

         in case the given instrument does not exists, or if an
         instrument with name equal to the name of the specified
         instrument already exists in the destination directory.

   Example:

      C: "MOVE DB_INSTRUMENT '/Piano Collection/Bosendorfer 290' '/Piano
      Collection/Acoustic'"

      S: "OK"

6.8.18.  Copying instruments

   The front-end can copy a specific instrument to another directory by
   sending the following command:

      COPY DB_INSTRUMENT <instr> <dst>

   Where <instr> is the absolute path name of the instrument to copy and
   <dst> is the directory where the instrument will be copied to.

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case the given instrument does not exists, or if an
         instrument with name equal to the name of the specified
         instrument already exists in the destination directory.

   Example:

      C: "COPY DB_INSTRUMENT '/Piano Collection/Bosendorfer 290'
      '/Acoustic/Pianos/'"

      S: "OK"


Schoenebeck            Expires September 12, 2019             [Page 111]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.8.19.  Changing the description of instrument

   The front-end can alter the description of a specific instrument by
   sending the following command:

      SET DB_INSTRUMENT DESCRIPTION <instr> <desc>

   Where <instr> is the absolute path name of the instrument and <desc>
   is the new description for the instrument (encapsulated into
   apostrophes, supporting escape sequences as described in chapter
   "Character Set and Escape Sequences (Section 7.1)").

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case the given instrument does not exists.

   Example:

      C: "SET DB_INSTRUMENT DESCRIPTION '/Piano Collection/Acoustic/
      Bosendorfer 290' 'No comment :)'"

      S: "OK"

6.8.20.  Finding instruments

   The front-end can search for instruments in specific directory by
   sending the following command:

      FIND DB_INSTRUMENTS [NON_RECURSIVE] <dir> <criteria-list>

   Where <dir> should be replaced by the absolute path name of the
   directory to search in.  If NON_RECURSIVE is specified, the
   directories located in subdirectories of the specified directory will
   not be searched. <criteria-list> is a list of search criterias in
   form of "key1=val1 key2=val2 ...".  The following criterias are
   allowed:

   Where <search-string> is either a regular expression, or a word list
   separated with spaces for OR search and with '+' for AND search.

   Possible Answers:


Schoenebeck            Expires September 12, 2019             [Page 112]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      A comma separated list with the absolute path names (encapsulated
      into apostrophes) of all instruments in the specified directory
      that satisfy the supplied search criterias.

      "ERR:<error-code>:<error-message>" -

         if the given directory does not exist.

   Example:

      C: "FIND DB_INSTRUMENTS '/Piano Collection'
      NAME='bosendorfer+290'"

      S: "'/Piano Collection/Bosendorfer 290'"

      C: "FIND DB_INSTRUMENTS '/Piano Collection' CREATED='2007-04-01
      09:30:13..'"

      S: "'/Piano Collection/Bosendorfer 290','/Piano Collection/
      Steinway D'"

6.8.21.  Getting job status information

   The front-end can ask for the current status of a particular database
   instruments job by sending the following command:

      GET DB_INSTRUMENTS_JOB INFO <job-id>

   Where <job-id> should be replaced by the numerical ID of the job the
   front-end is interested in.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the settings category name followed by a
      colon and then a space character <SP> and finally the info
      character string to that setting category.  At the moment the
      following categories are defined:


         FILES_TOTAL -

            The total number of files scheduled for scanning

         FILES_SCANNED -

            The current number of scanned files


Schoenebeck            Expires September 12, 2019             [Page 113]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         SCANNING -

            The absolute path name of the file which is currently being
            scanned

         STATUS -

            An integer value between 0 and 100 indicating the scanning
            progress percentage of the file which is currently being
            scanned

   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET DB_INSTRUMENTS_JOB INFO 2"

      S: "FILES_TOTAL: 12"

      "FILES_SCANNED: 7"

      "SCANNING: /home/me/gigs/Bosendorfer 290.gig"

      "STATUS: 42"

      "."

6.8.22.  Formatting the instruments database

   The front-end can remove all instruments and directories and re-
   create the instruments database structure (e.g., in case of a
   database corruption) by sending the following command:

      FORMAT INSTRUMENTS_DB

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         If the formatting of the instruments database failed.


Schoenebeck            Expires September 12, 2019             [Page 114]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.8.23.  Checking for lost instrument files

   The front-end can retrieve the list of all instrument files in the
   instruments database that don't exist in the filesystem by sending
   the following command:

      FIND LOST DB_INSTRUMENT_FILES

   Possible Answers:

      A comma separated list with the absolute path names (encapsulated
      into apostrophes) of all lost instrument files.

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message.

   Example:

      C: "FIND LOST DB_INSTRUMENT_FILES"

      S: "'/gigs/Bosendorfer 290.gig','/gigs/Steinway D.gig','/gigs/Free
      Piano.gig'"

6.8.24.  Replacing an instrument file

   The front-end can substitute all occurrences of an instrument file in
   the instruments database with a new one by sending the following
   command:

      SET DB_INSTRUMENT FILE_PATH <old_path> <new_path>

   Where <old_path> is the absolute path name of the instrument file to
   substitute with <new_path>.

   Possible Answers:

      "OK" -

         on success

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message.

   Example:


Schoenebeck            Expires September 12, 2019             [Page 115]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      C: "SET DB_INSTRUMENT FILE_PATH '/gigs/Bosendorfer 290.gig'
      '/gigs/pianos/Bosendorfer 290.gig'"

      S: "OK"

6.9.  Editing Instruments

   The sampler allows to edit instruments while playing with the sampler
   by spawning an external (3rd party) instrument editor application for
   a given instrument.  The 3rd party instrument editor applications
   have to place a respective plugin DLL file into the sampler's plugins
   directory.  The sampler will automatically try to load all plugin
   DLLs in that directory on startup and only on startup!

   At the moment there is only one command for this feature set, but
   this will most probably change in future.

6.9.1.  Opening an appropriate instrument editor application

   The front-end can request to open an appropriate instrument editor
   application by sending the following command:

      EDIT CHANNEL INSTRUMENT <sampler-channel>

   Where <sampler-channel> should be replaced by the number of the
   sampler channel as given by the "ADD CHANNEL" (Section 6.4.5) or
   "LIST CHANNELS" (Section 6.4.4) command.

   The sampler will try to ask all registered instrument editors (or to
   be more specific: their sampler plugins) whether they are capable to
   handle the instrument on the given sampler channel.  The sampler will
   simply use the first instrument editor application which replied with
   a positive answer and spawn that instrument editor application within
   the sampler's process and provide that application access to the
   instrument's data structures, so both applications can share and
   access the same instruments data at the same time, thus allowing to
   immediately hear changes with the sampler made by the instrument
   editor.

   Note: consequently instrument editors are always spawned locally on
   the same machine where the sampler is running on!

   Possible Answers:

      "OK" -

         when an appropriate instrument editor was launched


Schoenebeck            Expires September 12, 2019             [Page 116]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "WRN:<warning-code>:<warning-message>" -

         when an appropriate instrument editor was launched, but there
         are noteworthy issues

      "ERR:<error-code>:<error-message>" -

         when an appropriate instrument editor could not be launched

   Examples:

      C: "EDIT CHANNEL INSTRUMENT 0"

      S: "OK"

6.10.  Managing Files

   You can query detailed information about files located at the same
   system where the sampler instance is running on.  Using this command
   set allows to retrieve file information even remotely from another
   machine.

6.10.1.  Retrieving amount of instruments of a file

   The front-end can retrieve the amount of instruments within a given
   instrument file by sending the following command:

      GET FILE INSTRUMENTS <filename>

   Where <filename> is the name of the instrument file (encapsulated
   into apostrophes, supporting escape sequences as described in chapter
   "Character Set and Escape Sequences (Section 7.1)").

   The sampler will try to ask all sampler engines, whether they support
   the given file and ask the first engine with a positive answer for
   the amount of instruments.

   Possible Answers:

      On success, the sampler will answer by returning the amount of
      instruments.

      "ERR:<error-code>:<error-message>" -

         if the file could not be handled

   Examples:


Schoenebeck            Expires September 12, 2019             [Page 117]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      C: "GET FILE INSTRUMENTS 'D:/Sounds/Foo.gig'"

      S: "10"

6.10.2.  Retrieving all instruments of a file

   The front-end can retrieve a list of all instruments within a given
   instrument file by sending the following command:

      LIST FILE INSTRUMENTS <filename>

   Where <filename> is the name of the instrument file (encapsulated
   into apostrophes, supporting escape sequences as described in chapter
   "Character Set and Escape Sequences (Section 7.1)").

   The sampler will try to ask all sampler engines, whether they support
   the given file and ask the first engine with a positive answer for a
   list of IDs for the instruments in the given file.

   Possible Answers:

      On success, the sampler will answer by returning a comma separated
      list of instrument IDs.

      "ERR:<error-code>:<error-message>" -

         if the file could not be handled

   Examples:

      C: "LIST FILE INSTRUMENTS 'D:/Sounds/Foo.gig'"

      S: "0,1,2,3,4,5,6,7,8,9"

6.10.3.  Retrieving information about one instrument in a file

   The front-end can retrieve detailed information about a specific
   instrument within a given instrument file by sending the following
   command:

      GET FILE INSTRUMENT INFO <filename> <instr-id>

   Where <filename> is the name of the instrument file (encapsulated
   into apostrophes, supporting escape sequences as described in chapter
   "Character Set and Escape Sequences (Section 7.1)") and <instr-id> is
   the numeric instrument ID as returned by the "LIST FILE INSTRUMENTS"
   (Section 6.10.2) command.


Schoenebeck            Expires September 12, 2019             [Page 118]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   The sampler will try to ask all sampler engines, whether they support
   the given file and ask the first engine with a positive answer for
   information about the specific instrument in the given file.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the settings category name followed by a
      colon and then a space character <SP> and finally the info
      character string to that setting category.  At the moment the
      following categories are defined:


         NAME -

            name of the instrument as stored in the instrument file

         FORMAT_FAMILY -

            name of the sampler format of the given instrument

         FORMAT_VERSION -

            version of the sampler format the instrumen is stored as

         PRODUCT -

            official product name of the instrument as stored in the
            file

         ARTISTS -

            artists / sample library vendor of the instrument

         KEY_BINDINGS -

            comma separated list of integer values representing the
            instrument's key mapping in the range between 0 .. 127,
            reflecting the analog meaning of the MIDI specification.

         KEYSWITCH_BINDINGS -

            comma separated list of integer values representing the
            instrument's keyswitch mapping in the range between 0 ..
            127, reflecting the analog meaning of the MIDI
            specification.


Schoenebeck            Expires September 12, 2019             [Page 119]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET FILE INSTRUMENT INFO 'D:/Sounds/Foo.gig' 0"

      S: "NAME: Lunatic Loops"

      "FORMAT_FAMILY: GIG"

      "FORMAT_VERSION: 3"

      "PRODUCT: The Backbone Bongo Beats"

      "ARTISTS: Jimmy the Fish"

      "."

6.11.  Managing Effects

   There are two possible approaches to apply audio effects (e.g.
   reverb, delay, compression).  You can either a) load and apply
   internal effects or you can b) route effect sends directly to
   dedicated output channels of your audio device and apply effects
   externally (e.g. by routing those dedicated output channels to
   another application).

   This chapter describes how to load and manage internal effects.  If
   your intention is rather to apply effects externally, then you can
   omit this chapter.  For applying effects externally, you just need to
   create FX sends (Section 6.4.28) on the respective sampler channel(s)
   and adjust their destination audio channels (Section 6.4.34)
   appropriately, because by default FX sends are automatically routed
   directly to the audio output device.

   The sampler usually provides a set of internal audio effects.  The
   exact set of effects depends on the availability of third party
   effect plugins installed on the system where the sampler runs on
   (e.g.  LADSPA plugins).

   At the moment only "send effects" are supported.  Support for "insert
   effects" and "master effects" is planned to be added at a later
   point.

   The following commands allow to retrieve the set of internal effects
   available to the sampler, detailed information about those effects
   and to create and destroy instances of such effects.  After an


Schoenebeck            Expires September 12, 2019             [Page 120]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   instance of an effect is created, the effect instance can be inserted
   into the audio signal path of the sampler, e.g. as send effect.

   The sampler allows to create an arbitrary amount of so called send
   effect chains.  Each effect chain can host an arbitrary amount of
   effect instances.  The output of the first effect instance in an
   effect chain is fed to the input of the second effect instance of the
   chain and so on.  So effects in one chain are processed sequentially.
   Send effect chains however are processed in parallel to other send
   effect chains.  Audio signals of sampler channels are fed to send
   effects by creating FX sends to the respective sampler channel and
   assigning a destination send effect to that FX by using the "SET
   FX_SEND EFFECT" (Section 6.4.35) command.  The latter allows to route
   the FX send to the beginning of a send effect chain, as well as
   directly to any other position of the send effect chain.

6.11.1.  Retrieve amount of available effects

   The front-end can retrieve the amount of internal effects, available
   to the sampler by sending the following command:

      GET AVAILABLE_EFFECTS

   Possible Answers:

      The sampler will answer by returning the current number of effects
      available to the sampler.

   Examples:

      C: "GET AVAILABLE_EFFECTS"

      S: "129"

6.11.2.  Get list of available effects

   The set of available internal effects can change at runtime.  The
   front-end can retrieve the list of internal effects, available to the
   sampler by sending the following command:

      LIST AVAILABLE_EFFECTS

   Possible Answers:

      The sampler will answer by returning a comma separated list with
      numerical IDs of effects.  Note: the numercial ID of an effect is
      generated by the sampler for the current moment.  The numerical ID


Schoenebeck            Expires September 12, 2019             [Page 121]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      of the same effect can change at runtime, e.g. when the user
      requests a rescan of available effect plugins.

   Example:

      C: "LIST AVAILABLE_EFFECTS"

      S: "5,6,7,120,121,122,123,124"

6.11.3.  Retrieving general information about an effect

   The front-end can ask for general information about an effect by
   sending the following command:

      GET EFFECT INFO <effect-index>

   Where <effect-index> is the numerical ID of an effect as returned by
   the "LIST AVAILABLE_EFFECTS" (Section 6.11.2) command.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the effect information category name,
      followed by a colon and then a space character <SP> and finally
      the info character string to that effect information category.  At
      the moment the following categories are defined:


         SYSTEM -

            name of the effect plugin system the effect is based on
            (e.g.  "LADSPA")

         MODULE -

            module of the effect plugin system that contains this
            effect, the module is usually the dynamic-linked library
            (DLL) filename of the effect plugin, including full path
            (note that this filename may contain escape sequences
            (Section 7.1))

         NAME -

            character string defining the unique name of the effect
            within its module (note that the character string may
            contain escape sequences (Section 7.1))


Schoenebeck            Expires September 12, 2019             [Page 122]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         DESCRIPTION -

            human readable name of the effect, intended to be displayed
            in user interfaces (note that the character string may
            contain escape sequences (Section 7.1))

   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET EFFECT INFO 121"

      S: "SYSTEM: LADSPA"

      "MODULE: /usr/lib/ladspa/lowpass_iir_1891.so"

      "NAME: lowpass_iir"

      "DESCRIPTION: Glame Lowpass Filter"

      "."

6.11.4.  Creating an instance of an effect by its portable ID

   The front-end can spawn an instance of the desired effect by sending
   the following command:

      CREATE EFFECT_INSTANCE <effect-system> <module> <effect-name>

   Where <effect-system> is the "SYSTEM" field, <module> the "MODULE"
   field and <effect-name> the "NAME" field as returned by the "GET
   EFFECT INFO" (Section 6.11.3) command.  The filename of argument
   <module> and the character string of argument <effect-name> may
   contain escape sequences (Section 7.1).

   The sampler will try to load the requested effect and to create an
   instance of it.  To allow loading the same effect on a different
   machine, probably even running a completely different operating
   system (e.g.  Linux vs. Windows), the sampler tries to match <module>
   "softly".  That means it first tries to find an effect that exactly
   matches the given <module> argument.  If there is no exact match, the
   sampler will try to lower the restrictions on matching the <module>
   argument more and more, e.g. by ignoring upper / lower case
   differences and by ignoring the path of the DLL filename and file
   extension.  If there is still no match at the end, the sampler will
   try to ignore the <module> argument completely and as a last resort
   search for an effect that only matches the given <effect-system> and
   <effect-name> arguments.


Schoenebeck            Expires September 12, 2019             [Page 123]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Possible Answers:

      "OK[<effect-instance>]" -

         in case the effect instance was successfully created, where
         <effect-instance> is the numerical ID of the new effect
         instance

      "WRN:<warning-code>:<warning-message>" -

         in case the effect instance was spawned successfully, but there
         are noteworthy issue(s) related, providing an appropriate
         warning code and warning message

      "ERR:<error-code>:<error-message>" -

         if the effect could not be instantiated

   Examples:

      C: "CREATE EFFECT_INSTANCE LADSPA '/usr/lib/ladspa/
      mod_delay_1419.so' 'modDelay'"

      S: "OK[0]"

6.11.5.  Creating an instance of an effect by its numerical ID

   The front-end can spawn an instance of the desired effect by sending
   the following command:

      CREATE EFFECT_INSTANCE <effect-index>

   Where <effect-index> is the numerical ID of the effect as returned by
   the "LIST AVAILABLE_EFFECTS" (Section 6.11.2) command.

   The sampler will try to load the requested effect and to create an
   instance of it.

   Note: Since the numerical ID of a certain effect can change at any
   time, you should not use this command in LSCP files to restore a
   certain effect at a later time!  To store a sampler session including
   all its effects, use the portable text-based version of "CREATE
   EFFECT_INSTANCE" (Section 6.11.4) instead!  This allows to restore a
   sampler session with all its effects also on other machines, possibly
   even running a completely different operating system (e.g.  Linux vs.
   Windows), with different plugin directories or plugin DLL names.

   Possible Answers:


Schoenebeck            Expires September 12, 2019             [Page 124]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "OK[<effect-instance>]" -

         in case the effect instance was successfully created, where
         <effect-instance> is the numerical ID of the new effect
         instance

      "WRN:<warning-code>:<warning-message>" -

         in case the effect instance was spawned successfully, but there
         are noteworthy issue(s) related, providing an appropriate
         warning code and warning message

      "ERR:<error-code>:<error-message>" -

         if the effect could not be instantiated

   Examples:

      C: "CREATE EFFECT_INSTANCE 72"

      S: "OK[5]"

6.11.6.  Destroy an effect instance

   The front-end can destroy an unusued effect instance and thus freeing
   it from memory by sending the following command:

      DESTROY EFFECT_INSTANCE <effect-instance>

   Where <effect-instance> is the numerical ID of the effect instance as
   returned by the "CREATE EFFECT_INSTANCE" (Section 6.11.4) or "LIST
   EFFECT_INSTANCES" (Section 6.11.8) command.

   The effect instance can only be destroyed if it's not used in any
   part of the sampler's audio signal path anymore.  If the effect
   instance is still in use somewhere, trying to destroy the effect
   instance will result in an error message.

   Possible Answers:

      "OK" -

         in case the effect instance was successfully destroyed

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message


Schoenebeck            Expires September 12, 2019             [Page 125]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Examples:

      C: "DESTROY EFFECT_INSTANCE 5"

      S: "OK"

6.11.7.  Retrieve amount of effect instances

   The front-end can retrieve the current amount of effect instances by
   sending the following command:

      GET EFFECT_INSTANCES

   Possible Answers:

      The sampler will answer by returning the current number of effect
      instances created and not yet destroyed in the current sampler
      session.

   Examples:

      C: "GET EFFECT_INSTANCES"

      S: "14"

6.11.8.  Get list of effect instances

   The front-end can retrieve the current list of effect instances by
   sending the following command:

      LIST EFFECT_INSTANCES

   Possible Answers:

      The sampler will answer by returning a comma separated list with
      numerical IDs of effects instances.

   Example:

      C: "LIST EFFECT_INSTANCES"

      S: "9,11,14,15,16,17,25"

6.11.9.  Retrieving current information about an effect instance

   The front-end can ask for the current information about a particular
   effect instance by sending the following command:


Schoenebeck            Expires September 12, 2019             [Page 126]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      GET EFFECT_INSTANCE INFO <effect-instance>

   Where <effect-instance> is the numerical ID of an effect instance as
   returned by the "CREATE EFFECT_INSTANCE" (Section 6.11.4) or "LIST
   EFFECT_INSTANCES" (Section 6.11.8) command.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name, followed by
      a colon and then a space character <SP> and finally the info
      character string to that information category.  At the moment the
      following categories are defined:


         SYSTEM -

            name of the effect plugin system the effect is based on
            (e.g.  "LADSPA")

         MODULE -

            module of the effect plugin system that contains this
            effect, the module is usually the dynamic-linked library
            (DLL) filename of the effect plugin, including full path
            (note that this filename may contain escape sequences
            (Section 7.1))

         NAME -

            character string defining the unique name of the effect
            within its module (note that the character string may
            contain escape sequences (Section 7.1))

         DESCRIPTION -

            human readable name of the effect, intended to be displayed
            in user interfaces (note that the character string may
            contain escape sequences (Section 7.1))

         INPUT_CONTROLS -

            amount of input controls the effect instance provides, to
            allow controlling the effect parameters in realtime

   The mentioned fields above don't have to be in particular order.


Schoenebeck            Expires September 12, 2019             [Page 127]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Example:

      C: "GET EFFECT_INSTANCE INFO 3"

      S: "SYSTEM: LADSPA"

      "MODULE: /usr/lib/ladspa/mod_delay_1419.so"

      "NAME: modDelay"

      "DESCRIPTION: Modulatable delay"

      "INPUT_CONTROLS: 1"

      "."

6.11.10.  Retrieving information about an effect parameter

   Effects typically provide a certain set of effect parameters which
   can be altered by the user in realtime (e.g. depth of a reverb
   effect, duration of a delay effect, dry / wet signal ratio).  Those
   controllable effect parameters are called "input controls".  The
   front-end can ask for the current information of an effect instance's
   input control by sending the following command:

      GET EFFECT_INSTANCE_INPUT_CONTROL INFO <effect-instance> <input-
      control>

   Where <effect-instance> is the numerical ID of an effect instance as
   returned by the "CREATE EFFECT_INSTANCE" (Section 6.11.4) or "LIST
   EFFECT_INSTANCES" (Section 6.11.8) command and <input-control> is the
   index of the input control within the numerical bounds as returned by
   the "INPUT_CONTROLS" field of the "GET EFFECT_INSTANCE INFO"
   (Section 6.11.9) command.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name, followed by
      a colon and then a space character <SP> and finally the info
      character string to that information category.  There are
      information categories which are always returned, independent of
      the respective effect parameter and there are optional information
      categories which are only shown for certain effect parameters.  At
      the moment the following categories are defined:


Schoenebeck            Expires September 12, 2019             [Page 128]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         DESCRIPTION -

            (always returned) human readable name of the effect
            parameter, intended to be displayed in user interfaces (note
            that the character string may contain escape sequences
            (Section 7.1))

         VALUE -

            (always returned) current (optional dotted) floating point
            value of this effect parameter

         RANGE_MIN -

            (optionally returned) minimum allowed value for this effect
            parameter

         RANGE_MAX -

            (optionally returned) maximum allowed value for this effect
            parameter

         POSSIBILITIES -

            (optionally returned) comma separated list of (optional
            dotted) floating point numbers, reflecting the exact set of
            possible values for this effect parameter

         DEFAULT -

            (optionally returned) default value of this effect parameter

   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET EFFECT_INSTANCE_INPUT_CONTROL INFO 1 0"

      S: "DESCRIPTION: Base delay (s)"

      "VALUE: 0.500"

      "RANGE_MIN: 0.000"

      "."


Schoenebeck            Expires September 12, 2019             [Page 129]

Internet-Draft        LinuxSampler Control Protocol           March 2019


6.11.11.  Altering an effect parameter

   The front-end can alter the current value of an effect parameter by
   sending the following command:

      SET EFFECT_INSTANCE_INPUT_CONTROL VALUE <effect-instance> <input-
      control> <value>

   Where <effect-instance> is the numerical ID of the effect instance as
   returned by the "CREATE EFFECT_INSTANCE" (Section 6.11.4) or "LIST
   EFFECT_INSTANCES" (Section 6.11.8) command, <input-control> is the
   index of the input control within the numerical bounds as returned by
   the "INPUT_CONTROLS" field of the "GET EFFECT_INSTANCE INFO"
   (Section 6.11.9) command and <value> is the new (optional dotted)
   floating point value for this effect parameter.

   Possible Answers:

      "OK" -

         in case the effect was altered successfully

      "ERR:<error-code>:<error-message>" -

         in case it failed, providing an appropriate error code and
         error message

   Examples:

      C: "SET EFFECT_INSTANCE_INPUT_CONTROL VALUE 0 1 0.5"

      S: "OK"

6.11.12.  Retrieve amount of send effect chains

   The front-end can retrieve the current amount of send effect chains
   of an audio output device by sending the following command:

      GET SEND_EFFECT_CHAINS <audio-device>

   Where <audio-device> should be replaced by the numerical ID of the
   audio output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command.

   Possible Answers:


Schoenebeck            Expires September 12, 2019             [Page 130]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      The sampler will answer by returning the current number of send
      effect chains of the supplied audio output device.

   Examples:

      C: "GET SEND_EFFECT_CHAINS 0"

      S: "4"

6.11.13.  Retrieve list of send effect chains

   The front-end can retrieve the current list of send effect chains of
   an audio output device by sending the following command:

      LIST SEND_EFFECT_CHAINS <audio-device>

   Where <audio-device> should be replaced by the numerical ID of the
   audio output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command.

   Possible Answers:

      The sampler will answer by returning a comma separated list with
      numerical IDs of send effect chains of the supplied audio output
      device.

   Examples:

      C: "LIST SEND_EFFECT_CHAINS 0"

      S: "3,4,7"

6.11.14.  Add send effect chain

   The front-end can add a send effect chain by sending the following
   command:

      ADD SEND_EFFECT_CHAIN <audio-device>

   Where <audio-device> should be replaced by the numerical ID of the
   audio output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command.

   Possible Answers:

      "OK[<effect-chain>]" -


Schoenebeck            Expires September 12, 2019             [Page 131]

Internet-Draft        LinuxSampler Control Protocol           March 2019


         in case the send effect chain was added successfully, where
         <effect-chain> is the numerical ID of the new send effect chain

      "ERR:<error-code>:<error-message>" -

         if the send effect chain could not be added

   Examples:

      C: "ADD SEND_EFFECT_CHAIN 0"

      S: "OK[2]"

6.11.15.  Remove send effect chain

   The front-end can remove a send effect chain by sending the following
   command:

      REMOVE SEND_EFFECT_CHAIN <audio-device> <effect-chain>

   Where <audio-device> should be replaced by the numerical ID of the
   audio output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command and <effect-chain> by the numerical ID as returned by the
   "ADD SEND_EFFECT_CHAIN" (Section 6.11.14) or "LIST
   SEND_EFFECT_CHAINS" (Section 6.11.13) command.

   Possible Answers:

      "OK" -

         in case the send effect chain was removed successfully

      "ERR:<error-code>:<error-message>" -

         if the send effect chain could not be removed

   Examples:

      C: "REMOVE SEND_EFFECT_CHAIN 0 2"

      S: "OK"

6.11.16.  Retrieving information about a send effect chain

   The front-end can ask for information of a send effect chain by
   sending the following command:


Schoenebeck            Expires September 12, 2019             [Page 132]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      GET SEND_EFFECT_CHAIN INFO <audio-device> <effect-chain>

   Where <audio-device> should be replaced by the numerical ID of the
   audio output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command and <effect-chain> by the numerical ID as returned by the
   "ADD SEND_EFFECT_CHAIN" (Section 6.11.14) or "LIST
   SEND_EFFECT_CHAINS" (Section 6.11.13) command.

   Possible Answers:

      LinuxSampler will answer by sending a <CRLF> separated list.  Each
      answer line begins with the information category name, followed by
      a colon and then a space character <SP> and finally the info
      character string to that information category.  At the moment the
      following categories are defined:


         EFFECT_COUNT -

            amount of effects in this send effect chain

         EFFECT_SEQUENCE -

            comma separated list of the numerical IDs of the effect
            instances in this send effect chain, in the order as they
            are procssed in the effect chain

   The mentioned fields above don't have to be in particular order.

   Example:

      C: "GET SEND_EFFECT_CHAIN INFO 0 2"

      S: "EFFECT_COUNT: 3"

      "EFFECT_SEQUENCE: 31,4,7"

      "."

6.11.17.  Append effect instance to a send effect chain

   The front-end can add an unused effect instance to the end of a send
   effect chain by sending the following command:

      APPEND SEND_EFFECT_CHAIN EFFECT <audio-device> <effect-chain>
      <effect-instance>


Schoenebeck            Expires September 12, 2019             [Page 133]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Where <audio-device> should be replaced by the numerical ID of the
   audio output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command and <effect-chain> by the numerical ID as returned by the
   "ADD SEND_EFFECT_CHAIN" (Section 6.11.14) or "LIST
   SEND_EFFECT_CHAINS" (Section 6.11.13) command and <effect-instance>
   as returned by the "CREATE EFFECT_INSTANCE" (Section 6.11.4) or "LIST
   EFFECT_INSTANCES" (Section 6.11.8) command.

   Only unused effect instances can be added to the effect chain.
   Trying to add an effect instance which is already in use somewhere in
   the audio signal path of the sampler will result in an error.

   Possible Answers:

      "OK" -

         in case the effect instance was added successfully to the chain

      "ERR:<error-code>:<error-message>" -

         if the effect instance could not be added

   Examples:

      C: "APPEND SEND_EFFECT_CHAIN EFFECT 0 2 38"

      S: "OK"

6.11.18.  Insert effect instance to a send effect chain

   The front-end can add an unused effect instance to a certain position
   of a send effect chain by sending the following command:

      INSERT SEND_EFFECT_CHAIN EFFECT <audio-device> <effect-chain>
      <chain-pos> <effect-instance>

   Where <audio-device> should be replaced by the numerical ID of the
   audio output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command, <effect-chain> by the numerical ID as returned by the "ADD
   SEND_EFFECT_CHAIN" (Section 6.11.14) or "LIST SEND_EFFECT_CHAINS"
   (Section 6.11.13) command, <effect-instance> as returned by the
   "CREATE EFFECT_INSTANCE" (Section 6.11.4) or "LIST EFFECT_INSTANCES"
   (Section 6.11.8) command and <chain-pos> the exact position of the
   effect chain where the supplied effect shall be inserted to.


Schoenebeck            Expires September 12, 2019             [Page 134]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Only unused effect instances can be added to the effect chain.
   Trying to add an effect instance which is already in use somewhere in
   the audio signal path of the sampler will result in an error.

   Possible Answers:

      "OK" -

         in case the effect instance was added successfully to the chain

      "ERR:<error-code>:<error-message>" -

         if the effect instance could not be added

   Examples:

      C: "INSERT SEND_EFFECT_CHAIN EFFECT 0 2 4 38"

      S: "OK"

6.11.19.  Remove effect instance from send effect chain

   The front-end can remove an effect instance from a certain position
   of a send effect chain by sending the following command:

      REMOVE SEND_EFFECT_CHAIN EFFECT <audio-device> <effect-chain>
      <chain-pos>

   Where <audio-device> should be replaced by the numerical ID of the
   audio output device as given by the "CREATE AUDIO_OUTPUT_DEVICE"
   (Section 6.2.5) or "LIST AUDIO_OUTPUT_DEVICES" (Section 6.2.8)
   command, <effect-chain> by the numerical ID as returned by the "ADD
   SEND_EFFECT_CHAIN" (Section 6.11.14) or "LIST SEND_EFFECT_CHAINS"
   (Section 6.11.13) command and <chain-pos> the exact position of the
   effect instance to be removed from the effect chain.

   Possible Answers:

      "OK" -

         in case the effect instance was removed successfully

      "ERR:<error-code>:<error-message>" -

         if the effect instance could not be removed

   Examples:


Schoenebeck            Expires September 12, 2019             [Page 135]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      C: "REMOVE SEND_EFFECT_CHAIN EFFECT 0 2 4"

      S: "OK"

7.  Command Syntax

   The grammar of the control protocol as descibed in Section 6 is
   defined below using Backus-Naur Form (BNF as described in [RFC2234])
   where applicable.

   input =

      line

      / error

   line =

      statement LF

      / statement CR LF

   statement =

      /* epsilon (empty statement/line ignored) */

      / comment

      / command

   comment =

      '#'

      / comment '#'

      / comment SP

      / comment number

      / comment string

   command =

      ADD SP add_instruction

      / MAP SP map_instruction


Schoenebeck            Expires September 12, 2019             [Page 136]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / UNMAP SP unmap_instruction

      / GET SP get_instruction

      / CREATE SP create_instruction

      / DESTROY SP destroy_instruction

      / LIST SP list_instruction

      / LOAD SP load_instruction

      / REMOVE SP remove_instruction

      / SET SP set_instruction

      / SUBSCRIBE SP subscribe_event

      / UNSUBSCRIBE SP unsubscribe_event

      / RESET SP reset_instruction

      / CLEAR SP clear_instruction

      / FIND SP find_instruction

      / MOVE SP move_instruction

      / COPY SP copy_instruction

      / EDIT SP edit_instruction

      / FORMAT SP format_instruction

      / SEND SP send_instruction

      / APPEND SP append_instruction

      / INSERT SP insert_instruction

      / RESET

      / QUIT

   add_instruction =

      CHANNEL


Schoenebeck            Expires September 12, 2019             [Page 137]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / CHANNEL SP MIDI_INPUT SP sampler_channel SP device_index

      / CHANNEL SP MIDI_INPUT SP sampler_channel SP device_index SP
      midi_input_port_index

      / DB_INSTRUMENT_DIRECTORY SP db_path

      / DB_INSTRUMENTS SP NON_MODAL SP scan_mode SP db_path SP filename

      / DB_INSTRUMENTS SP NON_MODAL SP scan_mode SP FILE_AS_DIR SP
      db_path SP filename

      / DB_INSTRUMENTS SP scan_mode SP db_path SP filename

      / DB_INSTRUMENTS SP scan_mode SP FILE_AS_DIR SP db_path SP
      filename

      / DB_INSTRUMENTS SP NON_MODAL SP db_path SP filename

      / DB_INSTRUMENTS SP NON_MODAL SP db_path SP filename SP
      instrument_index

      / DB_INSTRUMENTS SP db_path SP filename

      / DB_INSTRUMENTS SP db_path SP filename SP instrument_index

      / MIDI_INSTRUMENT_MAP

      / MIDI_INSTRUMENT_MAP SP map_name

      / SEND_EFFECT_CHAIN SP device_index

   subscribe_event =

      AUDIO_OUTPUT_DEVICE_COUNT

      / AUDIO_OUTPUT_DEVICE_INFO

      / MIDI_INPUT_DEVICE_COUNT

      / MIDI_INPUT_DEVICE_INFO

      / CHANNEL_COUNT

      / CHANNEL_MIDI

      / DEVICE_MIDI


Schoenebeck            Expires September 12, 2019             [Page 138]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / VOICE_COUNT

      / STREAM_COUNT

      / BUFFER_FILL

      / CHANNEL_INFO

      / FX_SEND_COUNT

      / FX_SEND_INFO

      / MIDI_INSTRUMENT_MAP_COUNT

      / MIDI_INSTRUMENT_MAP_INFO

      / MIDI_INSTRUMENT_COUNT

      / MIDI_INSTRUMENT_INFO

      / DB_INSTRUMENT_DIRECTORY_COUNT

      / DB_INSTRUMENT_DIRECTORY_INFO

      / DB_INSTRUMENT_COUNT

      / DB_INSTRUMENT_INFO

      / DB_INSTRUMENTS_JOB_INFO

      / MISCELLANEOUS

      / TOTAL_STREAM_COUNT

      / TOTAL_VOICE_COUNT

      / GLOBAL_INFO

      / EFFECT_INSTANCE_COUNT

      / EFFECT_INSTANCE_INFO

      / SEND_EFFECT_CHAIN_COUNT

      / SEND_EFFECT_CHAIN_INFO

   unsubscribe_event =


Schoenebeck            Expires September 12, 2019             [Page 139]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      AUDIO_OUTPUT_DEVICE_COUNT

      / AUDIO_OUTPUT_DEVICE_INFO

      / MIDI_INPUT_DEVICE_COUNT

      / MIDI_INPUT_DEVICE_INFO

      / CHANNEL_COUNT

      / CHANNEL_MIDI

      / DEVICE_MIDI

      / VOICE_COUNT

      / STREAM_COUNT

      / BUFFER_FILL

      / CHANNEL_INFO

      / FX_SEND_COUNT

      / FX_SEND_INFO

      / MIDI_INSTRUMENT_MAP_COUNT

      / MIDI_INSTRUMENT_MAP_INFO

      / MIDI_INSTRUMENT_COUNT

      / MIDI_INSTRUMENT_INFO

      / DB_INSTRUMENT_DIRECTORY_COUNT

      / DB_INSTRUMENT_DIRECTORY_INFO

      / DB_INSTRUMENT_COUNT

      / DB_INSTRUMENT_INFO

      / DB_INSTRUMENTS_JOB_INFO

      / MISCELLANEOUS

      / TOTAL_STREAM_COUNT


Schoenebeck            Expires September 12, 2019             [Page 140]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / TOTAL_VOICE_COUNT

      / GLOBAL_INFO

      / EFFECT_INSTANCE_COUNT

      / EFFECT_INSTANCE_INFO

      / SEND_EFFECT_CHAIN_COUNT

      / SEND_EFFECT_CHAIN_INFO

   map_instruction =

      MIDI_INSTRUMENT SP modal_arg midi_map SP midi_bank SP midi_prog SP
      engine_name SP filename SP instrument_index SP volume_value

      / MIDI_INSTRUMENT SP modal_arg midi_map SP midi_bank SP midi_prog
      SP engine_name SP filename SP instrument_index SP volume_value SP
      instr_load_mode

      / MIDI_INSTRUMENT SP modal_arg midi_map SP midi_bank SP midi_prog
      SP engine_name SP filename SP instrument_index SP volume_value SP
      entry_name

      / MIDI_INSTRUMENT SP modal_arg midi_map SP midi_bank SP midi_prog
      SP engine_name SP filename SP instrument_index SP volume_value SP
      instr_load_mode SP entry_name

   unmap_instruction =

      MIDI_INSTRUMENT SP midi_map SP midi_bank SP midi_prog

   remove_instruction =

      CHANNEL SP sampler_channel

      / CHANNEL SP MIDI_INPUT SP sampler_channel

      / CHANNEL SP MIDI_INPUT SP sampler_channel SP device_index

      / CHANNEL SP MIDI_INPUT SP sampler_channel SP device_index SP
      midi_input_port_index

      / MIDI_INSTRUMENT_MAP SP midi_map

      / MIDI_INSTRUMENT_MAP SP ALL


Schoenebeck            Expires September 12, 2019             [Page 141]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / SEND_EFFECT_CHAIN SP device_index SP effect_chain

      / SEND_EFFECT_CHAIN SP EFFECT SP device_index SP effect_chain SP
      chain_pos

      / FX_SEND SP EFFECT SP sampler_channel SP fx_send_id

      / DB_INSTRUMENT_DIRECTORY SP FORCE SP db_path

      / DB_INSTRUMENT_DIRECTORY SP db_path

      / DB_INSTRUMENT SP db_path

   get_instruction =

      AVAILABLE_ENGINES

      / AVAILABLE_EFFECTS

      / EFFECT_INSTANCES

      / EFFECT SP INFO SP effect_index

      / EFFECT_INSTANCE SP INFO SP effect_instance

      / EFFECT_INSTANCE_INPUT_CONTROL SP INFO SP effect_instance SP
      input_control

      / SEND_EFFECT_CHAINS SP device_index

      / SEND_EFFECT_CHAIN SP INFO SP device_index SP effect_chain

      / AVAILABLE_MIDI_INPUT_DRIVERS

      / MIDI_INPUT_DRIVER SP INFO SP string

      / MIDI_INPUT_DRIVER_PARAMETER SP INFO SP string SP string

      / MIDI_INPUT_DRIVER_PARAMETER SP INFO SP string SP string SP
      key_val_list

      / AVAILABLE_AUDIO_OUTPUT_DRIVERS

      / AUDIO_OUTPUT_DRIVER SP INFO SP string

      / AUDIO_OUTPUT_DRIVER_PARAMETER SP INFO SP string SP string


Schoenebeck            Expires September 12, 2019             [Page 142]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / AUDIO_OUTPUT_DRIVER_PARAMETER SP INFO SP string SP string SP
      key_val_list

      / AUDIO_OUTPUT_DEVICES

      / MIDI_INPUT_DEVICES

      / AUDIO_OUTPUT_DEVICE SP INFO SP number

      / MIDI_INPUT_DEVICE SP INFO SP number

      / MIDI_INPUT_PORT SP INFO SP number SP number

      / MIDI_INPUT_PORT_PARAMETER SP INFO SP number SP number SP string

      / AUDIO_OUTPUT_CHANNEL SP INFO SP number SP number

      / AUDIO_OUTPUT_CHANNEL_PARAMETER SP INFO SP number SP number SP
      string

      / CHANNELS

      / CHANNEL SP INFO SP sampler_channel

      / CHANNEL SP BUFFER_FILL SP buffer_size_type SP sampler_channel

      / CHANNEL SP STREAM_COUNT SP sampler_channel

      / CHANNEL SP VOICE_COUNT SP sampler_channel

      / ENGINE SP INFO SP engine_name

      / SERVER SP INFO

      / TOTAL_STREAM_COUNT

      / TOTAL_VOICE_COUNT

      / TOTAL_VOICE_COUNT_MAX

      / MIDI_INSTRUMENTS SP midi_map

      / MIDI_INSTRUMENTS SP ALL

      / MIDI_INSTRUMENT SP INFO SP midi_map SP midi_bank SP midi_prog

      / MIDI_INSTRUMENT_MAPS


Schoenebeck            Expires September 12, 2019             [Page 143]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / MIDI_INSTRUMENT_MAP SP INFO SP midi_map

      / FX_SENDS SP sampler_channel

      / FX_SEND SP INFO SP sampler_channel SP fx_send_id

      / DB_INSTRUMENT_DIRECTORIES SP RECURSIVE SP db_path

      / DB_INSTRUMENT_DIRECTORIES SP db_path

      / DB_INSTRUMENT_DIRECTORY SP INFO SP db_path

      / DB_INSTRUMENTS SP RECURSIVE SP db_path

      / DB_INSTRUMENTS SP db_path

      / DB_INSTRUMENT SP INFO SP db_path

      / DB_INSTRUMENTS_JOB SP INFO SP number

      / VOLUME

      / VOICES

      / STREAMS

      / FILE SP INSTRUMENTS SP filename

      / FILE SP INSTRUMENT SP INFO SP filename SP instrument_index

   set_instruction =

      AUDIO_OUTPUT_DEVICE_PARAMETER SP number SP string '='
      param_val_list

      / AUDIO_OUTPUT_CHANNEL_PARAMETER SP number SP number SP string '='
      param_val_list

      / MIDI_INPUT_DEVICE_PARAMETER SP number SP string '='
      param_val_list

      / MIDI_INPUT_PORT_PARAMETER SP number SP number SP string '=' NONE

      / MIDI_INPUT_PORT_PARAMETER SP number SP number SP string '='
      param_val_list

      / EFFECT_INSTANCE_INPUT_CONTROL SP VALUE SP effect_instance SP
      input_control SP control_value


Schoenebeck            Expires September 12, 2019             [Page 144]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / CHANNEL SP set_chan_instruction

      / MIDI_INSTRUMENT_MAP SP NAME SP midi_map SP map_name

      / FX_SEND SP NAME SP sampler_channel SP fx_send_id SP fx_send_name

      / FX_SEND SP AUDIO_OUTPUT_CHANNEL SP sampler_channel SP fx_send_id
      SP audio_channel_index SP audio_channel_index

      / FX_SEND SP MIDI_CONTROLLER SP sampler_channel SP fx_send_id SP
      midi_ctrl

      / FX_SEND SP LEVEL SP sampler_channel SP fx_send_id SP
      volume_value

      / FX_SEND SP EFFECT SP sampler_channel SP fx_send_id SP
      effect_chain SP chain_pos

      / DB_INSTRUMENT_DIRECTORY SP NAME SP db_path SP stringval_escaped

      / DB_INSTRUMENT_DIRECTORY SP DESCRIPTION SP db_path SP
      stringval_escaped

      / DB_INSTRUMENT SP NAME SP db_path SP stringval_escaped

      / DB_INSTRUMENT SP DESCRIPTION SP db_path SP stringval_escaped

      / DB_INSTRUMENT SP FILE_PATH SP filename SP filename

      / ECHO SP boolean

      / SHELL SP INTERACT SP boolean

      / SHELL SP AUTO_CORRECT SP boolean

      / SHELL SP DOC SP boolean

      / VOLUME SP volume_value

      / VOICES SP number

      / STREAMS SP number

   create_instruction =

      AUDIO_OUTPUT_DEVICE SP string SP key_val_list

      / AUDIO_OUTPUT_DEVICE SP string


Schoenebeck            Expires September 12, 2019             [Page 145]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / MIDI_INPUT_DEVICE SP string SP key_val_list

      / MIDI_INPUT_DEVICE SP string

      / FX_SEND SP sampler_channel SP midi_ctrl

      / FX_SEND SP sampler_channel SP midi_ctrl SP fx_send_name

      / EFFECT_INSTANCE SP effect_index

      / EFFECT_INSTANCE SP effect_system SP module SP effect_name

   reset_instruction =

      CHANNEL SP sampler_channel

   clear_instruction =

      MIDI_INSTRUMENTS SP midi_map

      / MIDI_INSTRUMENTS SP ALL

   find_instruction =

      DB_INSTRUMENTS SP NON_RECURSIVE SP db_path SP query_val_list

      / DB_INSTRUMENTS SP db_path SP query_val_list

      / DB_INSTRUMENT_DIRECTORIES SP NON_RECURSIVE SP db_path SP
      query_val_list

      / DB_INSTRUMENT_DIRECTORIES SP db_path SP query_val_list

      / LOST SP DB_INSTRUMENT_FILES

   move_instruction =

      DB_INSTRUMENT_DIRECTORY SP db_path SP db_path

      / DB_INSTRUMENT SP db_path SP db_path

   copy_instruction =

      DB_INSTRUMENT_DIRECTORY SP db_path SP db_path

      / DB_INSTRUMENT SP db_path SP db_path

   destroy_instruction =


Schoenebeck            Expires September 12, 2019             [Page 146]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      AUDIO_OUTPUT_DEVICE SP number

      / MIDI_INPUT_DEVICE SP number

      / FX_SEND SP sampler_channel SP fx_send_id

      / EFFECT_INSTANCE SP number

   load_instruction =

      INSTRUMENT SP load_instr_args

      / ENGINE SP load_engine_args

   append_instruction =

      SEND_EFFECT_CHAIN SP EFFECT SP device_index SP effect_chain SP
      effect_instance

   insert_instruction =

      SEND_EFFECT_CHAIN SP EFFECT SP device_index SP effect_chain SP
      chain_pos SP effect_instance

   set_chan_instruction =

      AUDIO_OUTPUT_DEVICE SP sampler_channel SP device_index

      / AUDIO_OUTPUT_CHANNEL SP sampler_channel SP audio_channel_index
      SP audio_channel_index

      / AUDIO_OUTPUT_TYPE SP sampler_channel SP audio_output_type_name

      / MIDI_INPUT SP sampler_channel SP device_index SP
      midi_input_port_index SP midi_input_channel_index

      / MIDI_INPUT_DEVICE SP sampler_channel SP device_index

      / MIDI_INPUT_PORT SP sampler_channel SP midi_input_port_index

      / MIDI_INPUT_CHANNEL SP sampler_channel SP
      midi_input_channel_index

      / MIDI_INPUT_TYPE SP sampler_channel SP midi_input_type_name

      / VOLUME SP sampler_channel SP volume_value

      / MUTE SP sampler_channel SP boolean


Schoenebeck            Expires September 12, 2019             [Page 147]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / SOLO SP sampler_channel SP boolean

      / MIDI_INSTRUMENT_MAP SP sampler_channel SP midi_map

      / MIDI_INSTRUMENT_MAP SP sampler_channel SP NONE

      / MIDI_INSTRUMENT_MAP SP sampler_channel SP DEFAULT

   edit_instruction =

      CHANNEL SP INSTRUMENT SP sampler_channel

   format_instruction =

      INSTRUMENTS_DB

   modal_arg =

      /* epsilon (empty argument) */

      / NON_MODAL SP

   key_val_list =

      string '=' param_val_list

      / key_val_list SP string '=' param_val_list

   buffer_size_type =

      BYTES

      / PERCENTAGE

   list_instruction =

      AUDIO_OUTPUT_DEVICES

      / MIDI_INPUT_DEVICES

      / CHANNELS

      / CHANNEL SP MIDI_INPUTS SP sampler_channel

      / AVAILABLE_ENGINES

      / AVAILABLE_EFFECTS


Schoenebeck            Expires September 12, 2019             [Page 148]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / EFFECT_INSTANCES

      / SEND_EFFECT_CHAINS SP number

      / AVAILABLE_MIDI_INPUT_DRIVERS

      / AVAILABLE_AUDIO_OUTPUT_DRIVERS

      / MIDI_INSTRUMENTS SP midi_map

      / MIDI_INSTRUMENTS SP ALL

      / MIDI_INSTRUMENT_MAPS

      / FX_SENDS SP sampler_channel

      / DB_INSTRUMENT_DIRECTORIES SP RECURSIVE SP db_path

      / DB_INSTRUMENT_DIRECTORIES SP db_path

      / DB_INSTRUMENTS SP RECURSIVE SP db_path

      / DB_INSTRUMENTS SP db_path

      / FILE SP INSTRUMENTS SP filename

   send_instruction =

      CHANNEL SP MIDI_DATA SP string SP sampler_channel SP number SP
      number

   load_instr_args =

      filename SP instrument_index SP sampler_channel

      / NON_MODAL SP filename SP instrument_index SP sampler_channel

   load_engine_args =

      engine_name SP sampler_channel

   instr_load_mode =

      ON_DEMAND

      / ON_DEMAND_HOLD

      / PERSISTENT


Schoenebeck            Expires September 12, 2019             [Page 149]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   effect_instance =

      number

   device_index =

      number

   audio_channel_index =

      number

   audio_output_type_name =

      string

   midi_input_port_index =

      number

   midi_input_channel_index =

      number

      / ALL

   midi_input_type_name =

      string

   midi_map =

      number

   midi_bank =

      number

   midi_prog =

      number

   midi_ctrl =

      number

   volume_value =


Schoenebeck            Expires September 12, 2019             [Page 150]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      dotnum

      / number

   control_value =

      real

   sampler_channel =

      number

   instrument_index =

      number

   fx_send_id =

      number

   engine_name =

      string

   filename =

      path

   db_path =

      path

   map_name =

      stringval_escaped

   entry_name =

      stringval_escaped

   fx_send_name =

      stringval_escaped

   effect_name =

      stringval_escaped


Schoenebeck            Expires September 12, 2019             [Page 151]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   effect_index =

      number

   effect_chain =

      number

   chain_pos =

      number

   input_control =

      number

   param_val_list =

      param_val

      / param_val_list','param_val

   param_val =

      string

      / stringval

      / number

      / dotnum

   query_val_list =

      string '=' query_val

      / query_val_list SP string '=' query_val

   query_val =

      text_escaped

      / stringval_escaped

   scan_mode =

      RECURSIVE


Schoenebeck            Expires September 12, 2019             [Page 152]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      / NON_RECURSIVE

      / FLAT

   effect_system =

      string

   module =

      filename

7.1.  Character Set and Escape Sequences

   Older versions of this protocol up to and including v1.1 only
   supported the standard ASCII character set (ASCII code 0 - 127)
   [RFC20], all younger versions of this protocol however support the
   Extended ASCII character set (ASCII code 0 - 255).  The same group of
   younger protocols also support escape sequences, but only for
   certain, explicitly declared parts of the protocol.  The supported
   escape sequences are defined as follows:

   +------------------------+------------------------------------------+
   | ASCII Character        | Translated into (Name)                   |
   | Sequence               |                                          |
   +------------------------+------------------------------------------+
   | \n                     | new line                                 |
   |                        |                                          |
   | \r                     | carriage return                          |
   |                        |                                          |
   | \f                     | form feed                                |
   |                        |                                          |
   | \t                     | horizontal tab                           |
   |                        |                                          |
   | \v                     | vertical tab                             |
   |                        |                                          |
   | \'                     | apostrophe                               |
   |                        |                                          |
   | \"                     | quotation mark                           |
   |                        |                                          |
   | \\                     | backslash                                |
   |                        |                                          |
   | \OOO                   | three digit octal ASCII code of the      |
   |                        | character                                |
   |                        |                                          |
   | \xHH                   | two digit hex ASCII code of the          |
   |                        | character                                |
   +------------------------+------------------------------------------+


Schoenebeck            Expires September 12, 2019             [Page 153]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Notice: due to the transition of certain parts of the protocol which
   now support escape sequences, a slight backward incompatibility to
   protocols version v1.1 and younger has been introduced.  The only
   difference is that in parts of the protocol where escape characters
   are now supported, a backslash characters MUST be escaped as well
   (that is as double backslash), whereas in the old versions a single
   backslash was sufficient.

   The following LSCP commands support escape sequences as part of their
   filename / path based arguments and / or may contain a filename /
   path with escape sequences in their response:

      "LOAD INSTRUMENT" (Section 6.4.1)

      "GET CHANNEL INFO" (Section 6.4.10)

      "MAP MIDI_INSTRUMENT" (Section 6.7.7)

      "GET MIDI_INSTRUMENT INFO" (Section 6.7.11)

      "ADD DB_INSTRUMENT_DIRECTORY" (Section 6.8.1)

      "ADD DB_INSTRUMENTS" (Section 6.8.11)

      "REMOVE DB_INSTRUMENT_DIRECTORY" (Section 6.8.2)

      "REMOVE DB_INSTRUMENT" (Section 6.8.12)

      "GET DB_INSTRUMENT_DIRECTORIES" (Section 6.8.3)

      "LIST DB_INSTRUMENT_DIRECTORIES" (Section 6.8.4)

      "GET DB_INSTRUMENT_DIRECTORY INFO" (Section 6.8.5)

      "GET DB_INSTRUMENTS" (Section 6.8.13)

      "LIST DB_INSTRUMENTS" (Section 6.8.14)

      "GET DB_INSTRUMENT INFO" (Section 6.8.15)

      "SET DB_INSTRUMENT_DIRECTORY NAME" (Section 6.8.6)

      "SET DB_INSTRUMENT_DIRECTORY DESCRIPTION" (Section 6.8.9)

      "SET DB_INSTRUMENT NAME" (Section 6.8.16)

      "SET DB_INSTRUMENT DESCRIPTION" (Section 6.8.19)


Schoenebeck            Expires September 12, 2019             [Page 154]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "FIND DB_INSTRUMENTS" (Section 6.8.20)

      "FIND DB_INSTRUMENT_DIRECTORIES" (Section 6.8.10)

      "MOVE DB_INSTRUMENT" (Section 6.8.17)

      "MOVE DB_INSTRUMENT_DIRECTORY" (Section 6.8.7)

      "COPY DB_INSTRUMENT" (Section 6.8.18)

      "COPY DB_INSTRUMENT_DIRECTORY" (Section 6.8.8)

      "FIND LOST DB_INSTRUMENT_FILES" (Section 6.8.23)

      "SET DB_INSTRUMENT FILE_PATH" (Section 6.8.24)

      "GET FILE INSTRUMENTS" (Section 6.10.1)

      "LIST FILE INSTRUMENTS" (Section 6.10.2)

      "GET FILE INSTRUMENT INFO" (Section 6.10.3)

      "GET EFFECT INFO" (Section 6.11.3)

      "GET EFFECT_INSTANCE INFO" (Section 6.11.9)

      "CREATE EFFECT_INSTANCE" (Section 6.11.4)

   Note that the forward slash character ('/') has a special meaning in
   filename / path based arguments: it acts as separator of the nodes in
   the path, thus if a directory- or filename includes a forward slash
   (not intended as path node separator), you MUST escape that slash
   either with the respective hex escape sequence ("\x2f") or with the
   respective octal escape sequence ("\057").

   Note for Windows: file path arguments in LSCP are expected to use
   forward slashes as directory node separator similar to Unix based
   operating systems.  In contrast to Unix however a Windows typical
   drive character is expected to be prefixed to the path.  That is an
   original Windows file path like "D:\Sounds\My.gig" would become in
   LSCP: "D:/Sounds/My.gig".

   The following LSCP commands even support escape sequences as part of
   at least one of their text-based arguments (i.e. entity name,
   description) and / or may contain escape sequences in at least one of
   their text-based fields in their response:

      "GET SERVER INFO" (Section 6.6.5)


Schoenebeck            Expires September 12, 2019             [Page 155]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "GET ENGINE INFO" (Section 6.4.9)

      "GET CHANNEL INFO" (Section 6.4.10)

      "CREATE FX_SEND" (Section 6.4.28)

      "GET FX_SEND INFO" (Section 6.4.32)

      "SET FX_SEND NAME" (Section 6.4.33)

      "GET MIDI_INSTRUMENT INFO" (Section 6.7.11)

      "GET MIDI_INSTRUMENT_MAP INFO" (Section 6.7.5)

      "ADD MIDI_INSTRUMENT_MAP" (Section 6.7.1)

      "MAP MIDI_INSTRUMENT" (Section 6.7.7)

      "SET MIDI_INSTRUMENT_MAP NAME" (Section 6.7.6)

      "GET DB_INSTRUMENT_DIRECTORY INFO" (Section 6.8.5)

      "SET DB_INSTRUMENT_DIRECTORY NAME" (Section 6.8.6)

      "SET DB_INSTRUMENT_DIRECTORY DESCRIPTION" (Section 6.8.9)

      "FIND DB_INSTRUMENT_DIRECTORIES" (Section 6.8.10)

      "GET DB_INSTRUMENT INFO" (Section 6.8.15)

      "SET DB_INSTRUMENT NAME" (Section 6.8.16)

      "SET DB_INSTRUMENT DESCRIPTION" (Section 6.8.19)

      "FIND DB_INSTRUMENTS" (Section 6.8.20)

      "GET EFFECT INFO" (Section 6.11.3)

      "GET EFFECT_INSTANCE INFO" (Section 6.11.9)

      "CREATE EFFECT_INSTANCE" (Section 6.11.4)

   Please note that these lists are manually maintained.  If you find a
   command that also supports escape sequences we forgot to mention
   here, please report it!


Schoenebeck            Expires September 12, 2019             [Page 156]

Internet-Draft        LinuxSampler Control Protocol           March 2019


8.  Events

   This chapter will describe all currently defined events supported by
   LinuxSampler.

8.1.  Number of audio output devices changed

   Client may want to be notified when the total number of audio output
   devices on the back-end changes by issuing the following command:

      SUBSCRIBE AUDIO_OUTPUT_DEVICE_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:AUDIO_OUTPUT_DEVICE_COUNT:<devices>"

   where <devices> will be replaced by the new number of audio output
   devices.

8.2.  Audio output device's settings changed

   Client may want to be notified when changes were made to audio output
   devices on the back-end by issuing the following command:

      SUBSCRIBE AUDIO_OUTPUT_DEVICE_INFO

   Server will start sending the following notification messages:

      "NOTIFY:AUDIO_OUTPUT_DEVICE_INFO:<device-id>"

   where <device-id> will be replaced by the numerical ID of the audio
   output device, which settings has been changed.  The front-end will
   have to send the respective command to actually get the audio output
   device info.  Because these messages will be triggered by LSCP
   commands issued by other clients rather than real time events
   happening on the server, it is believed that an empty notification
   message is sufficient here.

8.3.  Number of MIDI input devices changed

   Client may want to be notified when the total number of MIDI input
   devices on the back-end changes by issuing the following command:

      SUBSCRIBE MIDI_INPUT_DEVICE_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:MIDI_INPUT_DEVICE_COUNT:<devices>"


Schoenebeck            Expires September 12, 2019             [Page 157]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   where <devices> will be replaced by the new number of MIDI input
   devices.

8.4.  MIDI input device's settings changed

   Client may want to be notified when changes were made to MIDI input
   devices on the back-end by issuing the following command:

      SUBSCRIBE MIDI_INPUT_DEVICE_INFO

   Server will start sending the following notification messages:

      "NOTIFY:MIDI_INPUT_DEVICE_INFO:<device-id>"

   where <device-id> will be replaced by the numerical ID of the MIDI
   input device, which settings has been changed.  The front-end will
   have to send the respective command to actually get the MIDI input
   device info.  Because these messages will be triggered by LSCP
   commands issued by other clients rather than real time events
   happening on the server, it is believed that an empty notification
   message is sufficient here.

8.5.  Number of sampler channels changed

   Client may want to be notified when the total number of channels on
   the back-end changes by issuing the following command:

      SUBSCRIBE CHANNEL_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:CHANNEL_COUNT:<channels>"

   where <channels> will be replaced by the new number of sampler
   channels.

8.6.  MIDI data on a sampler channel arrived

   Client may want to be notified when MIDI data arrive on sampler
   channels on back-end side, by issuing the following command:

      SUBSCRIBE CHANNEL_MIDI

   Server will start sending one of the the following notification
   messages:

      "NOTIFY:CHANNEL_MIDI:<channel-id> NOTE_ON <note> <velocity>"


Schoenebeck            Expires September 12, 2019             [Page 158]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      "NOTIFY:CHANNEL_MIDI:<channel-id> NOTE_OFF <note> <velocity>"

   where <channel-id> will be replaced by the ID of the sampler channel
   where the MIDI data arrived. <note> and <velocity> are integer values
   in the range between 0 .. 127, reflecting the analog meaning of the
   MIDI specification.

   CAUTION: no guarantee whatsoever will be made that MIDI events are
   actually all delivered by this mechanism!  With other words: events
   could be lost at any time!  This restriction was made to keep the RT-
   safeness of the backend's MIDI and audio thread unaffected by this
   feature.

8.7.  MIDI data on a MIDI input device arrived

   Client may want to be notified when MIDI data arrive on MIDI input
   devices by issuing the following command:

      SUBSCRIBE DEVICE_MIDI

   Server will start sending one of the the following notification
   messages:

      "NOTIFY:DEVICE_MIDI:<device-id> <port-id> NOTE_ON <note>
      <velocity>"

      "NOTIFY:DEVICE_MIDI:<device-id> <port-id> NOTE_OFF <note>
      <velocity>"

   where <device-id> <port-id> will be replaced by the IDs of the
   respective MIDI input device and the device's MIDI port where the
   MIDI data arrived. <note> and <velocity> are integer values in the
   range between 0 .. 127, reflecting the analog meaning of the MIDI
   specification.

   CAUTION: no guarantee whatsoever will be made that MIDI events are
   actually all delivered by this mechanism!  With other words: events
   could be lost at any time!  This restriction was made to keep the RT-
   safeness of the backend's MIDI and audio thread unaffected by this
   feature.

8.8.  Number of active voices changed

   Client may want to be notified when the number of voices on the back-
   end changes by issuing the following command:

      SUBSCRIBE VOICE_COUNT


Schoenebeck            Expires September 12, 2019             [Page 159]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Server will start sending the following notification messages:

      "NOTIFY:VOICE_COUNT:<sampler-channel> <voices>"

   where <sampler-channel> will be replaced by the sampler channel the
   voice count change occurred and <voices> by the new number of active
   voices on that channel.

8.9.  Number of active disk streams changed

   Client may want to be notified when the number of streams on the
   back-end changes by issuing the following command: SUBSCRIBE
   STREAM_COUNT

      SUBSCRIBE STREAM_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:STREAM_COUNT:<sampler-channel> <streams>"

   where <sampler-channel> will be replaced by the sampler channel the
   stream count change occurred and <streams> by the new number of
   active disk streams on that channel.

8.10.  Disk stream buffer fill state changed

   Client may want to be notified when the buffer fill state of a disk
   stream on the back-end changes by issuing the following command:

      SUBSCRIBE BUFFER_FILL

   Server will start sending the following notification messages:

      "NOTIFY:BUFFER_FILL:<sampler-channel> <fill-data>"

   where <sampler-channel> will be replaced by the sampler channel the
   buffer fill state change occurred on and <fill-data> will be replaced
   by the buffer fill data for this channel as described in
   Section 6.4.13 as if the "GET CHANNEL BUFFER_FILL PERCENTAGE"
   (Section 6.4.13) command was issued on this channel.

8.11.  Channel information changed

   Client may want to be notified when changes were made to sampler
   channels on the back-end by issuing the following command:

      SUBSCRIBE CHANNEL_INFO


Schoenebeck            Expires September 12, 2019             [Page 160]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Server will start sending the following notification messages:

      "NOTIFY:CHANNEL_INFO:<sampler-channel>"

   where <sampler-channel> will be replaced by the sampler channel the
   channel info change occurred.  The front-end will have to send the
   respective command to actually get the channel info.  Because these
   messages will be triggered by LSCP commands issued by other clients
   rather than real time events happening on the server, it is believed
   that an empty notification message is sufficient here.

8.12.  Number of effect sends changed

   Client may want to be notified when the number of effect sends on a
   particular sampler channel is changed by issuing the following
   command:

      SUBSCRIBE FX_SEND_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:FX_SEND_COUNT:<channel-id> <fx-sends>"

   where <channel-id> will be replaced by the numerical ID of the
   sampler channel, on which the effect sends number is changed and <fx-
   sends> will be replaced by the new number of effect sends on that
   channel.

8.13.  Effect send information changed

   Client may want to be notified when changes were made to effect sends
   on a a particular sampler channel by issuing the following command:

      SUBSCRIBE FX_SEND_INFO

   Server will start sending the following notification messages:

      "NOTIFY:FX_SEND_INFO:<channel-id> <fx-send-id>"

   where <channel-id> will be replaced by the numerical ID of the
   sampler channel, on which an effect send entity is changed and <fx-
   send-id> will be replaced by the numerical ID of the changed effect
   send.


Schoenebeck            Expires September 12, 2019             [Page 161]

Internet-Draft        LinuxSampler Control Protocol           March 2019


8.14.  Total number of active voices changed

   Client may want to be notified when the total number of voices on the
   back-end changes by issuing the following command:

      SUBSCRIBE TOTAL_VOICE_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:TOTAL_VOICE_COUNT:<voices>"

   where <voices> will be replaced by the new number of all currently
   active voices.

8.15.  Total number of active disk streams changed

   Client may want to be notified when the total number of disk streams
   on the back-end changes by issuing the following command:

      SUBSCRIBE TOTAL_STREAM_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:TOTAL_STREAM_COUNT:<streams>"

   where <streams> will be replaced by the new number of all currently
   active disk streams.

8.16.  Number of MIDI instrument maps changed

   Client may want to be notified when the number of MIDI instrument
   maps on the back-end changes by issuing the following command:

      SUBSCRIBE MIDI_INSTRUMENT_MAP_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:MIDI_INSTRUMENT_MAP_COUNT:<maps>"

   where <maps> will be replaced by the new number of MIDI instrument
   maps.

8.17.  MIDI instrument map information changed

   Client may want to be notified when changes were made to MIDI
   instrument maps on the back-end by issuing the following command:

      SUBSCRIBE MIDI_INSTRUMENT_MAP_INFO


Schoenebeck            Expires September 12, 2019             [Page 162]

Internet-Draft        LinuxSampler Control Protocol           March 2019


   Server will start sending the following notification messages:

      "NOTIFY:MIDI_INSTRUMENT_MAP_INFO:<map-id>"

   where <map-id> will be replaced by the numerical ID of the MIDI
   instrument map, for which information changes occurred.  The front-
   end will have to send the respective command to actually get the MIDI
   instrument map info.  Because these messages will be triggered by
   LSCP commands issued by other clients rather than real time events
   happening on the server, it is believed that an empty notification
   message is sufficient here.

8.18.  Number of MIDI instruments changed

   Client may want to be notified when the number of MIDI instrument
   maps on the back-end changes by issuing the following command:

      SUBSCRIBE MIDI_INSTRUMENT_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:MIDI_INSTRUMENT_COUNT:<map-id> <instruments>"

   where <map-id> is the numerical ID of the MIDI instrument map, in
   which the nuber of instruments has changed and <instruments> will be
   replaced by the new number of MIDI instruments in the specified map.

8.19.  MIDI instrument information changed

   Client may want to be notified when changes were made to MIDI
   instruments on the back-end by issuing the following command:

      SUBSCRIBE MIDI_INSTRUMENT_INFO

   Server will start sending the following notification messages:

      "NOTIFY:MIDI_INSTRUMENT_INFO:<map-id> <bank> <program>"

   where <map-id> will be replaced by the numerical ID of the MIDI
   instrument map, in which a MIDI instrument is changed. <bank> and
   <program> specifies the location of the changed MIDI instrument in
   the map.  The front-end will have to send the respective command to
   actually get the MIDI instrument info.  Because these messages will
   be triggered by LSCP commands issued by other clients rather than
   real time events happening on the server, it is believed that an
   empty notification message is sufficient here.


Schoenebeck            Expires September 12, 2019             [Page 163]

Internet-Draft        LinuxSampler Control Protocol           March 2019


8.20.  Global settings changed

   Client may want to be notified when changes to the global settings of
   the sampler were made by issuing the following command:

      SUBSCRIBE GLOBAL_INFO

   Server will start sending the following types of notification
   messages:

      "NOTIFY:GLOBAL_INFO:VOLUME <volume>" - Notifies that the golbal
      volume of the sampler is changed, where <volume> will be replaced
      by the optional dotted floating point value, reflecting the new
      global volume parameter.

      "NOTIFY:GLOBAL_INFO:VOICES <max-voices>" - Notifies that the
      golbal limit of the sampler for maximum voices is changed, where
      <max-voices> will be an integer value, reflecting the new global
      voice limit parameter.

      "NOTIFY:GLOBAL_INFO:STREAMS <max-streams>" - Notifies that the
      golbal limit of the sampler for maximum disk streams is changed,
      where <max-streams> will be an integer value, reflecting the new
      global disk streams limit parameter.

8.21.  Number of database instrument directories changed

   Client may want to be notified when the number of instrument
   directories in a particular directory in the instruments database is
   changed by issuing the following command:

      SUBSCRIBE DB_INSTRUMENT_DIRECTORY_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:DB_INSTRUMENT_DIRECTORY_COUNT:<dir-path>"

   where <dir-path> will be replaced by the absolute path name of the
   directory in the instruments database, in which the number of
   directories is changed.

   Note that when a non-empty directory is removed, this event is not
   sent for the subdirectories in that directory.


Schoenebeck            Expires September 12, 2019             [Page 164]

Internet-Draft        LinuxSampler Control Protocol           March 2019


8.22.  Database instrument directory information changed

   Client may want to be notified when changes were made to directories
   in the instruments database by issuing the following command:

      SUBSCRIBE DB_INSTRUMENT_DIRECTORY_INFO

   Server will start sending the following notification messages:

      "NOTIFY:DB_INSTRUMENT_DIRECTORY_INFO:<dir-path>"

   where <dir-path> will be replaced by the absolute path name of the
   directory, for which information changes occurred.  The front-end
   will have to send the respective command to actually get the updated
   directory info.  Because these messages will be triggered by LSCP
   commands issued by other clients rather than real time events
   happening on the server, it is believed that an empty notification
   message is sufficient here.

      "NOTIFY:DB_INSTRUMENT_DIRECTORY_INFO:NAME <old-dir-path> <new-
      name>"

   where <old-dir-path> is the old absolute path name of the directory
   (encapsulated into apostrophes), which name is changes and <new-name>
   is the new name of the directory, encapsulated into apostrophes.

8.23.  Number of database instruments changed

   Client may want to be notified when the number of instruments in a
   particular directory in the instruments database is changed by
   issuing the following command:

      SUBSCRIBE DB_INSTRUMENT_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:DB_INSTRUMENT_COUNT:<dir-path>"

   where <dir-path> will be replaced by the absolute path name of the
   directory in the instruments database, in which the number of
   instruments is changed.

   Note that when a non-empty directory is removed, this event is not
   sent for the instruments in that directory.


Schoenebeck            Expires September 12, 2019             [Page 165]

Internet-Draft        LinuxSampler Control Protocol           March 2019


8.24.  Database instrument information changed

   Client may want to be notified when changes were made to instruments
   in the instruments database by issuing the following command:

      SUBSCRIBE DB_INSTRUMENT_INFO

   Server will start sending the following notification messages:

      "NOTIFY:DB_INSTRUMENT_INFO:<instr-path>"

   where <instr-path> will be replaced by the absolute path name of the
   instrument, which settings are changed.  The front-end will have to
   send the respective command to actually get the updated directory
   info.  Because these messages will be triggered by LSCP commands
   issued by other clients rather than real time events happening on the
   server, it is believed that an empty notification message is
   sufficient here.

      "NOTIFY:DB_INSTRUMENT_INFO:NAME <old-instr-path> <new-name>"

   where <old-instr-path> is the old absolute path name of the
   instrument (encapsulated into apostrophes), which name is changes and
   <new-name> is the new name of the instrument, encapsulated into
   apostrophes.

8.25.  Database job status information changed

   Client may want to be notified when the status of particular database
   instruments job is changed by issuing the following command:

      SUBSCRIBE DB_INSTRUMENTS_JOB_INFO

   Server will start sending the following notification messages:

      "NOTIFY:DB_INSTRUMENTS_JOB_INFO:<job-id>"

   where <job-id> will be replaced by the numerical ID of the job, which
   status is changed.  The front-end will have to send the respective
   command to actually get the status info.  Because these messages will
   be triggered by LSCP commands issued by other clients rather than
   real time events happening on the server, it is believed that an
   empty notification message is sufficient here.


Schoenebeck            Expires September 12, 2019             [Page 166]

Internet-Draft        LinuxSampler Control Protocol           March 2019


8.26.  Number of effect instances changed

   Client may want to be notified when the number of effect instances is
   changed by issuing the following command:

      SUBSCRIBE EFFECT_INSTANCE_COUNT

   Server will start sending the following notification messages:

      "EFFECT_INSTANCE_COUNT:<instances>"

   where <instances> will be replaced by the new number of effect
   instances.

8.27.  Effect instance information changed

   Client may want to be notified when changes were made to effect
   instances on the back-end by issuing the following command:

      SUBSCRIBE EFFECT_INSTANCE_INFO

   Server will start sending the following notification messages:

      "EFFECT_INSTANCE_INFO:<instance-id>"

   where <instance-id> will be replaced by the numerical ID of the
   effect instance.

8.28.  Number of send effect chains changed

   Client may want to be notified when the number of send effect chains
   is changed by issuing the following command:

      SUBSCRIBE SEND_EFFECT_CHAIN_COUNT

   Server will start sending the following notification messages:

      "NOTIFY:SEND_EFFECT_CHAIN_COUNT:<device-id> <chains>"

   where <device-id> will be replaced by the numerical ID of the audio
   output device, in which the number of send effect chains is changed
   and <chains> will be replaced by the new number of send effect
   chains.


Schoenebeck            Expires September 12, 2019             [Page 167]

Internet-Draft        LinuxSampler Control Protocol           March 2019


8.29.  Send effect chain information changed

   Client may want to be notified when changes were made to send effect
   chains on the back-end by issuing the following command:

      SUBSCRIBE SEND_EFFECT_CHAIN_INFO

   Server will start sending the following notification messages:

      "SEND_EFFECT_CHAIN_INFO:<device-id> <chain-id> <instances>" -
      Notifies that the number of effect instances in a particular send
      effect chain is changed, where <device-id> will be replaced by the
      numerical ID of the audio output device the send effect chain
      belongs to, <chain-id> will be replaced by the numerical ID of the
      send effect chain in which the number of effect instances has
      changed and <instances> will be replaced by the new number of
      effect instances in the specified send effect chain.

8.30.  Miscellaneous and debugging events

   Client may want to be notified of miscellaneous and debugging events
   occurring at the server by issuing the following command:

      SUBSCRIBE MISCELLANEOUS

   Server will start sending the following notification messages:

      "NOTIFY:MISCELLANEOUS:<string>"

   where <string> will be replaced by whatever data server wants to send
   to the client.  Client MAY display this data to the user AS IS to
   facilitate debugging.

9.  Security Considerations

   As there is so far no method of authentication and authorization
   defined and so not required for a client applications to succeed to
   connect, running LinuxSampler might be a security risk for the host
   system the LinuxSampler instance is running on.

10.  Acknowledgments

   This document has benefited greatly from the comments of the
   following people, discussed on the LinuxSampler developer's mailing
   list:

      Rui Nuno Capela


Schoenebeck            Expires September 12, 2019             [Page 168]

Internet-Draft        LinuxSampler Control Protocol           March 2019


      Vladimir Senkov

      Mark Knecht

      Grigor Iliev

11.  References

   [RFC20]    UCLA, "ASCII format for Network Interchange", RFC 20,
              1969.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", RFC 2119, 1997.

   [RFC2234]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
              Specifications", RFC 2234, 1997.

   [RFC793]   Defense Advanced Research Projects Agency, "TRANSMISSION
              CONTROL PROTOCOL", RFC 793, 1981.

Author's Address

   C. Schoenebeck (editor)
   LinuxSampler.org
   Crudebyte Engineering
   Hofgartenstr. 3
   74189 Weinsberg
   Germany

   Phone: +49 7134 911614
   Email: cuse@users.sf.net


Schoenebeck            Expires September 12, 2019             [Page 169]