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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
#if defined(MACOSX) || defined(GP2X)
#include "backends/mixer/doublebuffersdl/doublebuffersdl-mixer.h"
DoubleBufferSDLMixerManager::DoubleBufferSDLMixerManager()
:
_soundMutex(0), _soundCond(0), _soundThread(0),
_soundThreadIsRunning(false), _soundThreadShouldQuit(false) {
}
DoubleBufferSDLMixerManager::~DoubleBufferSDLMixerManager() {
deinitThreadedMixer();
}
void DoubleBufferSDLMixerManager::startAudio() {
_soundThreadIsRunning = false;
_soundThreadShouldQuit = false;
// Create mutex and condition variable
_soundMutex = SDL_CreateMutex();
_soundCond = SDL_CreateCond();
// Create two sound buffers
_activeSoundBuf = 0;
uint bufSize = _obtainedRate.samples * 4;
_soundBufSize = bufSize;
_soundBuffers[0] = (byte *)calloc(1, bufSize);
_soundBuffers[1] = (byte *)calloc(1, bufSize);
_soundThreadIsRunning = true;
// Finally start the thread
_soundThread = SDL_CreateThread(mixerProducerThreadEntry, this);
SdlMixerManager::startAudio();
}
void DoubleBufferSDLMixerManager::mixerProducerThread() {
byte nextSoundBuffer;
SDL_LockMutex(_soundMutex);
while (true) {
// Wait till we are allowed to produce data
SDL_CondWait(_soundCond, _soundMutex);
if (_soundThreadShouldQuit)
break;
// Generate samples and put them into the next buffer
nextSoundBuffer = _activeSoundBuf ^ 1;
_mixer->mixCallback(_soundBuffers[nextSoundBuffer], _soundBufSize);
// Swap buffers
_activeSoundBuf = nextSoundBuffer;
}
SDL_UnlockMutex(_soundMutex);
}
int SDLCALL DoubleBufferSDLMixerManager::mixerProducerThreadEntry(void *arg) {
DoubleBufferSDLMixerManager *mixer = (DoubleBufferSDLMixerManager *)arg;
assert(mixer);
mixer->mixerProducerThread();
return 0;
}
void DoubleBufferSDLMixerManager::deinitThreadedMixer() {
// Kill thread?? _soundThread
if (_soundThreadIsRunning) {
// Signal the producer thread to end, and wait for it to actually finish.
_soundThreadShouldQuit = true;
SDL_CondBroadcast(_soundCond);
SDL_WaitThread(_soundThread, NULL);
// Kill the mutex & cond variables.
// Attention: AT this point, the mixer callback must not be running
// anymore, else we will crash!
SDL_DestroyMutex(_soundMutex);
SDL_DestroyCond(_soundCond);
_soundThreadIsRunning = false;
free(_soundBuffers[0]);
free(_soundBuffers[1]);
}
}
void DoubleBufferSDLMixerManager::callbackHandler(byte *samples, int len) {
assert(_mixer);
assert((int)_soundBufSize == len);
// Lock mutex, to ensure our data is not overwritten by the producer thread
SDL_LockMutex(_soundMutex);
// Copy data from the current sound buffer
memcpy(samples, _soundBuffers[_activeSoundBuf], len);
// Unlock mutex and wake up the produced thread
SDL_UnlockMutex(_soundMutex);
SDL_CondSignal(_soundCond);
}
#endif
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