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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(SDL_BACKEND)
#include "backends/mixer/sdl/sdl-mixer.h"
#include "common/system.h"
#include "common/config-manager.h"
#ifdef GP2X
#define SAMPLES_PER_SEC 11025
#else
#define SAMPLES_PER_SEC 22050
#endif
//#define SAMPLES_PER_SEC 44100
SdlMixerManager::SdlMixerManager()
:
_mixer(0),
_audioSuspended(false) {
}
SdlMixerManager::~SdlMixerManager() {
_mixer->setReady(false);
SDL_CloseAudio();
delete _mixer;
}
void SdlMixerManager::init() {
// Start SDL Audio subsystem
if (SDL_InitSubSystem(SDL_INIT_AUDIO) == -1) {
error("Could not initialize SDL: %s", SDL_GetError());
}
// Get the desired audio specs
SDL_AudioSpec desired = getAudioSpec(SAMPLES_PER_SEC);
// Start SDL audio with the desired specs
if (SDL_OpenAudio(&desired, &_obtainedRate) != 0) {
warning("Could not open audio device: %s", SDL_GetError());
_mixer = new Audio::MixerImpl(g_system, desired.freq);
assert(_mixer);
_mixer->setReady(false);
} else {
debug(1, "Output sample rate: %d Hz", _obtainedRate.freq);
_mixer = new Audio::MixerImpl(g_system, _obtainedRate.freq);
assert(_mixer);
_mixer->setReady(true);
startAudio();
}
}
SDL_AudioSpec SdlMixerManager::getAudioSpec(uint32 outputRate) {
SDL_AudioSpec desired;
// Determine the desired output sampling frequency.
uint32 samplesPerSec = 0;
if (ConfMan.hasKey("output_rate"))
samplesPerSec = ConfMan.getInt("output_rate");
if (samplesPerSec <= 0)
samplesPerSec = outputRate;
// Determine the sample buffer size. We want it to store enough data for
// at least 1/16th of a second (though at most 8192 samples). Note
// that it must be a power of two. So e.g. at 22050 Hz, we request a
// sample buffer size of 2048.
uint32 samples = 8192;
while (samples * 16 > samplesPerSec * 2)
samples >>= 1;
memset(&desired, 0, sizeof(desired));
desired.freq = samplesPerSec;
desired.format = AUDIO_S16SYS;
desired.channels = 2;
desired.samples = (uint16)samples;
desired.callback = sdlCallback;
desired.userdata = this;
return desired;
}
void SdlMixerManager::startAudio() {
// Start the sound system
SDL_PauseAudio(0);
}
void SdlMixerManager::callbackHandler(byte *samples, int len) {
assert(_mixer);
_mixer->mixCallback(samples, len);
}
void SdlMixerManager::sdlCallback(void *this_, byte *samples, int len) {
SdlMixerManager *manager = (SdlMixerManager *)this_;
assert(manager);
manager->callbackHandler(samples, len);
}
void SdlMixerManager::suspendAudio() {
SDL_CloseAudio();
_audioSuspended = true;
}
int SdlMixerManager::resumeAudio() {
if (!_audioSuspended)
return -2;
if (SDL_OpenAudio(&_obtainedRate, NULL) < 0){
return -1;
}
SDL_PauseAudio(0);
_audioSuspended = false;
return 0;
}
#endif
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