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/*************************************************************************** |
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* * |
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* LinuxSampler - modular, streaming capable sampler * |
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* * |
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* Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck * |
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* * |
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* This program is free software; you can redistribute it and/or modify * |
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* it under the terms of the GNU General Public License as published by * |
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* the Free Software Foundation; either version 2 of the License, or * |
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* (at your option) any later version. * |
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* * |
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* This program is distributed in the hope that it will be useful, * |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of * |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * |
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* GNU General Public License for more details. * |
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* * |
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* You should have received a copy of the GNU General Public License * |
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* along with this program; if not, write to the Free Software * |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, * |
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* MA 02111-1307 USA * |
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***************************************************************************/ |
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|
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#include "Event.h" |
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|
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namespace LinuxSampler { |
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|
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/** |
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* Create an EventGenerator. |
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* |
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* @param SampleRate - sample rate of the sampler engine's audio output |
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* signal (in Hz) |
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*/ |
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EventGenerator::EventGenerator(uint SampleRate) { |
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uiSampleRate = SampleRate; |
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uiSamplesProcessed = 0; |
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FragmentTime.end = CreateTimeStamp(); |
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} |
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|
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/** |
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* Updates the time stamps for the beginning and end of the current audio |
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* fragment. This is needed to be able to calculate the respective sample |
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* point later to which an event belongs to. |
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* |
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* @param SamplesToProcess - number of sample points to process in this |
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* audio fragment cycle |
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*/ |
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void EventGenerator::UpdateFragmentTime(uint SamplesToProcess) { |
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// update time stamp for this audio fragment cycle |
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FragmentTime.begin = FragmentTime.end; |
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FragmentTime.end = CreateTimeStamp(); |
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// recalculate sample ratio for this audio fragment |
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time_stamp_t fragmentDuration = FragmentTime.end - FragmentTime.begin; |
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FragmentTime.sample_ratio = (float) uiSamplesProcessed / (float) fragmentDuration; |
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// store amount of samples to process for the next cycle |
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uiSamplesProcessed = SamplesToProcess; |
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} |
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|
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/** |
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* Create a new event with the current time as time stamp. |
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*/ |
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Event EventGenerator::CreateEvent() { |
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return Event(this, CreateTimeStamp()); |
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} |
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|
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/** |
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* Creates a real time stamp for the current moment. Out of efficiency this |
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* is implemented in inline assembly for each CPU independently; we currently |
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* don't use a generic solution for CPUs that are not yet covered by the |
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* assembly code, instead an error message is prompted on compile time, forcing |
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* the user to contact us. |
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*/ |
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EventGenerator::time_stamp_t EventGenerator::CreateTimeStamp() { |
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#if defined(__i386__) || defined(__x86_64__) |
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uint64_t t; |
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__asm__ __volatile__ ("rdtsc" : "=A" (t)); |
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return t >> 8; |
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#elif defined(__ia64__) |
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time_stamp_t t; |
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__asm__ __volatile__ ("mov %0=ar.itc" : "=r"(t)); |
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return t; |
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#elif defined(__powerpc__) |
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time_stamp_t t; |
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__asm__ __volatile__ ( |
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"98: mftb %0\n" |
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"99:\n" |
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".section __ftr_fixup,\"a\"\n" |
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" .long %1\n" |
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" .long 0\n" |
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" .long 98b\n" |
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" .long 99b\n" |
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".previous" |
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: "=r" (t) : "i" (0x00000100) |
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); |
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return t; |
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#elif defined(__alpha__) |
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time_stamp_t t; |
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__asm__ __volatile__ ("rpcc %0" : "=r"(t)); |
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return t; |
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#else // we don't want to use a slow generic solution |
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# error Sorry, LinuxSampler lacks time stamp code for your system. |
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# error Please report this error and the CPU you are using to the LinuxSampler developers mailing list! |
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#endif |
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} |
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|
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/** |
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* Will be called by an EventGenerator to create a new Event. |
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*/ |
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Event::Event(EventGenerator* pGenerator, time_stamp_t Time) { |
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pEventGenerator = pGenerator; |
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TimeStamp = Time; |
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iFragmentPos = -1; |
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} |
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|
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} // namespace LinuxSampler |