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Diffstat (limited to 'backends/mixer/sdl/sdl-mixer.cpp')
-rw-r--r-- | backends/mixer/sdl/sdl-mixer.cpp | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/backends/mixer/sdl/sdl-mixer.cpp b/backends/mixer/sdl/sdl-mixer.cpp new file mode 100644 index 0000000000..b9e04532f8 --- /dev/null +++ b/backends/mixer/sdl/sdl-mixer.cpp @@ -0,0 +1,143 @@ +/* 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(WIN32) || defined(UNIX) || defined(MACOSX) + +#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(); + + // 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() { + 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 = SAMPLES_PER_SEC; + + // 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 |