drivers/audio/AudioOutputDevice.h

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#ifndef __LS_AUDIOOUTPUTDEVICE_H__
#define __LS_AUDIOOUTPUTDEVICE_H__

#include <set>
#include <map>
#include <vector>
#include <stdexcept>

#include "../../common/global.h"
#include "../../common/LinuxSamplerException.h"
#include "../Device.h"
#include "../DeviceParameter.h"
#include "../../engines/common/Engine.h"
#include "AudioChannel.h"

namespace LinuxSampler {

    // just symbol prototyping
    class Engine;

    /** Abstract base class for audio output drivers in LinuxSampler
     *
     * This class will be derived by specialized classes which implement the
     * connection to a specific audio output system (e.g. Alsa, Jack,
     * CoreAudio).
     */
    class AudioOutputDevice : public Device {
        public:

            /////////////////////////////////////////////////////////////////
            // Device parameters

            class ParameterActive : public DeviceCreationParameterBool {
                public:
                    ParameterActive( void ) : DeviceCreationParameterBool()                  { InitWithDefault();                                  }
                    ParameterActive( String s ) : DeviceCreationParameterBool(s)             {}
                    virtual String Description()                                             { return "Enable / disable device";                   }
                    virtual bool   Fix()                                                     { return false;                                       }
                    virtual bool   Mandatory()                                               { return false;                                       }
                    virtual std::map<String,DeviceCreationParameter*> DependsAsParameters()  { return std::map<String,DeviceCreationParameter*>(); }
                    virtual optional<bool> DefaultAsBool(std::map<String,String> Parameters) { return true;                                        }
                    virtual void OnSetValue(bool b) throw (LinuxSamplerException)            { if (b) ((AudioOutputDevice*)pDevice)->Play(); else ((AudioOutputDevice*)pDevice)->Stop();       }
                    static String Name( void ) { return "active"; }
            };

            class ParameterSampleRate : public DeviceCreationParameterInt {
                public:
                    ParameterSampleRate() : DeviceCreationParameterInt()                            { InitWithDefault();                                  }
                    ParameterSampleRate( String s ) : DeviceCreationParameterInt(s)                 {}
                    virtual String Description()                                                    { return "Output sample rate";                        }
                    virtual bool   Fix()                                                            { return true;                                        }
                    virtual bool   Mandatory()                                                      { return false;                                       }
                    virtual std::map<String,DeviceCreationParameter*> DependsAsParameters()         { return std::map<String,DeviceCreationParameter*>(); }
                    virtual optional<int>    DefaultAsInt(std::map<String,String> Parameters)       { return 44100;                                       }
                    virtual optional<int>    RangeMinAsInt(std::map<String,String> Parameters)      { return optional<int>::nothing;                      }
                    virtual optional<int>    RangeMaxAsInt(std::map<String,String> Parameters)      { return optional<int>::nothing;                      }
                    virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters) { return std::vector<int>();                          }
                    virtual void             OnSetValue(int i) throw (LinuxSamplerException)        { /* cannot happen, as parameter is fix */            }
                    static String Name( void ) { return "samplerate"; }
            };

            class ParameterChannels : public DeviceCreationParameterInt {
                public:
                    ParameterChannels() : DeviceCreationParameterInt()                              { InitWithDefault();                                  }
                    ParameterChannels( String s ) : DeviceCreationParameterInt(s)                   {}
                    virtual String Description()                                                    { return "Number of output channels";                 }
                    virtual bool   Fix()                                                            { return false;                                       }
                    virtual bool   Mandatory()                                                      { return false;                                       }
                    virtual std::map<String,DeviceCreationParameter*> DependsAsParameters()         { return std::map<String,DeviceCreationParameter*>(); }
                    virtual optional<int>    DefaultAsInt(std::map<String,String> Parameters)       { return 2;                                           }
                    virtual optional<int>    RangeMinAsInt(std::map<String,String> Parameters)      { return optional<int>::nothing;                      }
                    virtual optional<int>    RangeMaxAsInt(std::map<String,String> Parameters)      { return optional<int>::nothing;                      }
                    virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters) { return std::vector<int>();                          }
                    virtual void             OnSetValue(int i) throw (LinuxSamplerException)        { ((AudioOutputDevice*)pDevice)->AcquireChannels(i);    }
                    static String Name( void ) { return "channels"; }
            };


            /////////////////////////////////////////////////////////////////
            // abstract methods
            //     (these have to be implemented by the descendant)

            /**
             * Start playback of audio signal on the audio device. It's the
             * responsibility of the implementing audio device to call the
             * RenderAudio(uint Samples) method of all connected engines.
             * This will cause the engines to continue to render 'Samples'
             * number of audio sample points and the engines will
             * automatically add their audio signals to the audio buffers of
             * the audio channels of this audio device. So the implementing
             * audio device just has to access the buffers of it's audio
             * channels.
             *
             * @throws AudioOutputException  if playback can not be started
             * @see AudioChannel
             */
            virtual void Play() = 0;

            /**
             * Returns true if the audio device is currently playing back.
             */
            virtual bool IsPlaying() = 0;

            /**
             * Stop playback of audio signal on the audio device. The
             * implementing audio device will stop calling the RenderAudio()
             * method of all connected engines and close it's connection to
             * audio output system.
             */
            virtual void Stop() = 0;

            /**
             * This method will usually be called by the sampler engines that
             * are connected to this audio device to inform the audio device
             * how much audio channels the engine(s) need. It's the
             * responsibility of the audio device to offer that amount of
             * audio channels - again: this is not an option this is a must!
             * The engines will assume to be able to access those audio
             * channels right after. If the audio driver is not able to offer
             * that much channels, it can simply create mix channels which
             * are then just mixed to the 'real' audio channels. See
             * AudioChannel.h for details about channels and mix channels.
             *
             * @param Channels - amount of output channels required by
             *                   a sampler engine
             * @throws AudioOutputException  if desired amount of channels
             *                               cannot be offered
             * @see AudioChannel
             */
            virtual void AcquireChannels(uint Channels) = 0;

            /**
             * Maximum amount of sample points the implementing audio
             * device will ever demand the sampler engines to write in one
             * fragment cycle / period. Simple audio device drivers usually
             * have a fixed fragment size, so those devices just would return
             * the fragment size in this method.
             *
             * @returns  max. amount of sample points ever
             */
            virtual uint MaxSamplesPerCycle() = 0;

            /**
             * Playback samplerate the audio device uses. The sampler engines
             * currently assume this to be a constant value for the whole
             * life time of an instance of the implementing audio device.
             *
             * @returns  sample rate in Hz
             */
            virtual uint SampleRate() = 0;

            /**
             * Return the audio output device driver type name.
             */
            virtual String Driver() = 0;

            /////////////////////////////////////////////////////////////////
            // normal methods
            //     (usually not to be overriden by descendant)

            /**
             * Connect given sampler engine to this audio output device. The
             * engine will be added to the Engines container of this audio
             * device and the engine will also automatically be informed
             * about the connection.
             *
             * @param pEngine - sampler engine
             */
            void Connect(Engine* pEngine);

            /**
             * Disconnect given sampler engine from this audio output device.
             * Removes given sampler engine reference from the Engines
             * container of this audio device.
             *
             * @param pEngine - sampler engine
             */
            void Disconnect(Engine* pEngine);

            /**
             * Returns audio channel with index \a ChannelIndex or NULL if
             * index out of bounds.
             */
            AudioChannel* Channel(uint ChannelIndex);

            std::map<String,DeviceCreationParameter*> DeviceParameters();


        protected:
            std::set<Engine*>                         Engines;     ///< All sampler engines that are connected to the audio output device.
            std::vector<AudioChannel*>                Channels;    ///< All audio channels of the audio output device. This is just a container; the descendant has to create channels by himself.
            std::map<String,DeviceCreationParameter*> Parameters;  ///< All device parameters.

            AudioOutputDevice(std::map<String,DeviceCreationParameter*> DriverParameters);

            virtual ~AudioOutputDevice();

            /**
             * This method should be called by the AudioOutputDevice
             * descendant to let all connected engines proceed to render the
             * given amount of sample points. The engines will place their
             * calculated audio data by themselfes into the buffers of the
             * respective AudioChannel objects, so the implementing audio
             * output device just has to copy the AudioChannel buffers to
             * the output buffer(s) of its audio system.
             *
             * @returns  0 on success or the last error return code of one
             *           engine
             */
            int RenderAudio(uint Samples);

            /**
             * This can be called as an alternative to RenderAudio() for
             * just writing silence to the audio output buffers and not
             * calling the connected sampler engines for rendering audio, so
             * to provide a method to stop playback if the used audio output
             * system doesn't provide a better way.
             *
             * @returns  0 on success
             */
            int RenderSilence(uint Samples);

            friend class Sampler; // allow Sampler class to destroy audio devices

    };

    /**
     * Audio output exception that should be thrown by the AudioOutputDevice
     * descendants in case initialization of the audio output system failed
     * (which should be done in the constructor of the AudioOutputDevice
     * descendant).
     */
    class AudioOutputException : public LinuxSamplerException {
        public:
            AudioOutputException(const std::string& msg) : LinuxSamplerException(msg) {}
    };
}

#endif // __LS_AUDIOOUTPUTDEVICE_H__
1	schoenebeck	200	/***************************************************************************
2			* *
3			* LinuxSampler - modular, streaming capable sampler *
4			* *
5			* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck *
6			* *
7			* This program is free software; you can redistribute it and/or modify *
8			* it under the terms of the GNU General Public License as published by *
9			* the Free Software Foundation; either version 2 of the License, or *
10			* (at your option) any later version. *
11			* *
12			* This program is distributed in the hope that it will be useful, *
13			* but WITHOUT ANY WARRANTY; without even the implied warranty of *
14			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15			* GNU General Public License for more details. *
16			* *
17			* You should have received a copy of the GNU General Public License *
18			* along with this program; if not, write to the Free Software *
19			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20			* MA 02111-1307 USA *
21			***************************************************************************/
22
23			#ifndef __LS_AUDIOOUTPUTDEVICE_H__
24			#define __LS_AUDIOOUTPUTDEVICE_H__
25
26			#include <set>
27			#include <map>
28			#include <vector>
29			#include <stdexcept>
30
31			#include "../../common/global.h"
32			#include "../../common/LinuxSamplerException.h"
33	schoenebeck	207	#include "../Device.h"
34	schoenebeck	200	#include "../DeviceParameter.h"
35			#include "../../engines/common/Engine.h"
36			#include "AudioChannel.h"
37
38			namespace LinuxSampler {
39
40			// just symbol prototyping
41			class Engine;
42
43			/** Abstract base class for audio output drivers in LinuxSampler
44			*
45			* This class will be derived by specialized classes which implement the
46			* connection to a specific audio output system (e.g. Alsa, Jack,
47			* CoreAudio).
48			*/
49	schoenebeck	207	class AudioOutputDevice : public Device {
50	schoenebeck	200	public:
51
52			/////////////////////////////////////////////////////////////////
53			// Device parameters
54
55			class ParameterActive : public DeviceCreationParameterBool {
56			public:
57			ParameterActive( void ) : DeviceCreationParameterBool() { InitWithDefault(); }
58			ParameterActive( String s ) : DeviceCreationParameterBool(s) {}
59			virtual String Description() { return "Enable / disable device"; }
60			virtual bool Fix() { return false; }
61			virtual bool Mandatory() { return false; }
62			virtual std::map<String,DeviceCreationParameter> DependsAsParameters() { return std::map<String,DeviceCreationParameter>(); }
63			virtual optional<bool> DefaultAsBool(std::map<String,String> Parameters) { return true; }
64			virtual void OnSetValue(bool b) throw (LinuxSamplerException) { if (b) ((AudioOutputDevice)pDevice)->Play(); else ((AudioOutputDevice)pDevice)->Stop(); }
65			static String Name( void ) { return "active"; }
66			};
67
68			class ParameterSampleRate : public DeviceCreationParameterInt {
69			public:
70			ParameterSampleRate() : DeviceCreationParameterInt() { InitWithDefault(); }
71			ParameterSampleRate( String s ) : DeviceCreationParameterInt(s) {}
72			virtual String Description() { return "Output sample rate"; }
73			virtual bool Fix() { return true; }
74			virtual bool Mandatory() { return false; }
75			virtual std::map<String,DeviceCreationParameter> DependsAsParameters() { return std::map<String,DeviceCreationParameter>(); }
76			virtual optional<int> DefaultAsInt(std::map<String,String> Parameters) { return 44100; }
77			virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters) { return optional<int>::nothing; }
78			virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters) { return optional<int>::nothing; }
79			virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters) { return std::vector<int>(); }
80			virtual void OnSetValue(int i) throw (LinuxSamplerException) { /* cannot happen, as parameter is fix */ }
81			static String Name( void ) { return "samplerate"; }
82			};
83
84			class ParameterChannels : public DeviceCreationParameterInt {
85			public:
86			ParameterChannels() : DeviceCreationParameterInt() { InitWithDefault(); }
87			ParameterChannels( String s ) : DeviceCreationParameterInt(s) {}
88			virtual String Description() { return "Number of output channels"; }
89			virtual bool Fix() { return false; }
90			virtual bool Mandatory() { return false; }
91			virtual std::map<String,DeviceCreationParameter> DependsAsParameters() { return std::map<String,DeviceCreationParameter>(); }
92			virtual optional<int> DefaultAsInt(std::map<String,String> Parameters) { return 2; }
93			virtual optional<int> RangeMinAsInt(std::map<String,String> Parameters) { return optional<int>::nothing; }
94			virtual optional<int> RangeMaxAsInt(std::map<String,String> Parameters) { return optional<int>::nothing; }
95			virtual std::vector<int> PossibilitiesAsInt(std::map<String,String> Parameters) { return std::vector<int>(); }
96			virtual void OnSetValue(int i) throw (LinuxSamplerException) { ((AudioOutputDevice*)pDevice)->AcquireChannels(i); }
97			static String Name( void ) { return "channels"; }
98			};
99
100
101			/////////////////////////////////////////////////////////////////
102			// abstract methods
103			// (these have to be implemented by the descendant)
104
105			/**
106			* Start playback of audio signal on the audio device. It's the
107			* responsibility of the implementing audio device to call the
108			* RenderAudio(uint Samples) method of all connected engines.
109			* This will cause the engines to continue to render 'Samples'
110			* number of audio sample points and the engines will
111			* automatically add their audio signals to the audio buffers of
112			* the audio channels of this audio device. So the implementing
113			* audio device just has to access the buffers of it's audio
114			* channels.
115			*
116			* @throws AudioOutputException if playback can not be started
117			* @see AudioChannel
118			*/
119			virtual void Play() = 0;
120
121			/**
122			* Returns true if the audio device is currently playing back.
123			*/
124			virtual bool IsPlaying() = 0;
125
126			/**
127			* Stop playback of audio signal on the audio device. The
128			* implementing audio device will stop calling the RenderAudio()
129			* method of all connected engines and close it's connection to
130			* audio output system.
131			*/
132			virtual void Stop() = 0;
133
134			/**
135			* This method will usually be called by the sampler engines that
136			* are connected to this audio device to inform the audio device
137			* how much audio channels the engine(s) need. It's the
138			* responsibility of the audio device to offer that amount of
139			* audio channels - again: this is not an option this is a must!
140			* The engines will assume to be able to access those audio
141			* channels right after. If the audio driver is not able to offer
142			* that much channels, it can simply create mix channels which
143			* are then just mixed to the 'real' audio channels. See
144			* AudioChannel.h for details about channels and mix channels.
145			*
146			* @param Channels - amount of output channels required by
147			* a sampler engine
148			* @throws AudioOutputException if desired amount of channels
149			* cannot be offered
150			* @see AudioChannel
151			*/
152			virtual void AcquireChannels(uint Channels) = 0;
153
154			/**
155			* Maximum amount of sample points the implementing audio
156			* device will ever demand the sampler engines to write in one
157			* fragment cycle / period. Simple audio device drivers usually
158			* have a fixed fragment size, so those devices just would return
159			* the fragment size in this method.
160			*
161			* @returns max. amount of sample points ever
162			*/
163			virtual uint MaxSamplesPerCycle() = 0;
164
165			/**
166			* Playback samplerate the audio device uses. The sampler engines
167			* currently assume this to be a constant value for the whole
168			* life time of an instance of the implementing audio device.
169			*
170			* @returns sample rate in Hz
171			*/
172			virtual uint SampleRate() = 0;
173
174			/**
175			* Return the audio output device driver type name.
176			*/
177			virtual String Driver() = 0;
178
179			/////////////////////////////////////////////////////////////////
180			// normal methods
181			// (usually not to be overriden by descendant)
182
183			/**
184			* Connect given sampler engine to this audio output device. The
185			* engine will be added to the Engines container of this audio
186			* device and the engine will also automatically be informed
187			* about the connection.
188			*
189			* @param pEngine - sampler engine
190			*/
191			void Connect(Engine* pEngine);
192
193			/**
194			* Disconnect given sampler engine from this audio output device.
195			* Removes given sampler engine reference from the Engines
196			* container of this audio device.
197			*
198			* @param pEngine - sampler engine
199			*/
200			void Disconnect(Engine* pEngine);
201
202			/**
203			* Returns audio channel with index \a ChannelIndex or NULL if
204			* index out of bounds.
205			*/
206			AudioChannel* Channel(uint ChannelIndex);
207
208			std::map<String,DeviceCreationParameter*> DeviceParameters();
209
210
211			protected:
212			std::set<Engine*> Engines; ///< All sampler engines that are connected to the audio output device.
213			std::vector<AudioChannel*> Channels; ///< All audio channels of the audio output device. This is just a container; the descendant has to create channels by himself.
214			std::map<String,DeviceCreationParameter*> Parameters; ///< All device parameters.
215
216			AudioOutputDevice(std::map<String,DeviceCreationParameter*> DriverParameters);
217
218			virtual ~AudioOutputDevice();
219
220			/**
221			* This method should be called by the AudioOutputDevice
222			* descendant to let all connected engines proceed to render the
223			* given amount of sample points. The engines will place their
224			* calculated audio data by themselfes into the buffers of the
225			* respective AudioChannel objects, so the implementing audio
226			* output device just has to copy the AudioChannel buffers to
227			* the output buffer(s) of its audio system.
228			*
229			* @returns 0 on success or the last error return code of one
230			* engine
231			*/
232			int RenderAudio(uint Samples);
233
234			/**
235			* This can be called as an alternative to RenderAudio() for
236			* just writing silence to the audio output buffers and not
237			* calling the connected sampler engines for rendering audio, so
238			* to provide a method to stop playback if the used audio output
239			* system doesn't provide a better way.
240			*
241			* @returns 0 on success
242			*/
243			int RenderSilence(uint Samples);
244
245			friend class Sampler; // allow Sampler class to destroy audio devices
246
247			};
248
249			/**
250			* Audio output exception that should be thrown by the AudioOutputDevice
251			* descendants in case initialization of the audio output system failed
252			* (which should be done in the constructor of the AudioOutputDevice
253			* descendant).
254			*/
255			class AudioOutputException : public LinuxSamplerException {
256			public:
257			AudioOutputException(const std::string& msg) : LinuxSamplerException(msg) {}
258			};
259			}
260
261			#endif // __LS_AUDIOOUTPUTDEVICE_H__