/** * OpenAL cross platform audio library * Copyright (C) 2018 by authors. * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * Or go to http://www.gnu.org/copyleft/lgpl.html */ #include "config.h" #include "backends/sdl2.h" #include #include #include #include #include "AL/al.h" #include "alcmain.h" #include "almalloc.h" #include "alu.h" #include "logging.h" #include namespace { #ifdef _WIN32 #define DEVNAME_PREFIX "OpenAL Soft on " #else #define DEVNAME_PREFIX "" #endif constexpr ALCchar defaultDeviceName[] = DEVNAME_PREFIX "Default Device"; struct Sdl2Backend final : public BackendBase { Sdl2Backend(ALCdevice *device) noexcept : BackendBase{device} { } ~Sdl2Backend() override; static void audioCallbackC(void *ptr, Uint8 *stream, int len); void audioCallback(Uint8 *stream, int len); ALCenum open(const ALCchar *name) override; bool reset() override; bool start() override; void stop() override; void lock() override; void unlock() override; SDL_AudioDeviceID mDeviceID{0u}; ALuint mFrameSize{0}; ALuint mFrequency{0u}; DevFmtChannels mFmtChans{}; DevFmtType mFmtType{}; ALuint mUpdateSize{0u}; DEF_NEWDEL(Sdl2Backend) }; Sdl2Backend::~Sdl2Backend() { if(mDeviceID) SDL_CloseAudioDevice(mDeviceID); mDeviceID = 0; } void Sdl2Backend::audioCallbackC(void *ptr, Uint8 *stream, int len) { static_cast(ptr)->audioCallback(stream, len); } void Sdl2Backend::audioCallback(Uint8 *stream, int len) { const auto ulen = static_cast(len); assert((ulen % mFrameSize) == 0); aluMixData(mDevice, stream, ulen / mFrameSize); } ALCenum Sdl2Backend::open(const ALCchar *name) { SDL_AudioSpec want{}, have{}; want.freq = static_cast(mDevice->Frequency); switch(mDevice->FmtType) { case DevFmtUByte: want.format = AUDIO_U8; break; case DevFmtByte: want.format = AUDIO_S8; break; case DevFmtUShort: want.format = AUDIO_U16SYS; break; case DevFmtShort: want.format = AUDIO_S16SYS; break; case DevFmtUInt: /* fall-through */ case DevFmtInt: want.format = AUDIO_S32SYS; break; case DevFmtFloat: want.format = AUDIO_F32; break; } want.channels = (mDevice->FmtChans == DevFmtMono) ? 1 : 2; want.samples = static_cast(mDevice->UpdateSize); want.callback = &Sdl2Backend::audioCallbackC; want.userdata = this; /* Passing nullptr to SDL_OpenAudioDevice opens a default, which isn't * necessarily the first in the list. */ if(!name || strcmp(name, defaultDeviceName) == 0) mDeviceID = SDL_OpenAudioDevice(nullptr, SDL_FALSE, &want, &have, SDL_AUDIO_ALLOW_ANY_CHANGE); else { const size_t prefix_len = strlen(DEVNAME_PREFIX); if(strncmp(name, DEVNAME_PREFIX, prefix_len) == 0) mDeviceID = SDL_OpenAudioDevice(name+prefix_len, SDL_FALSE, &want, &have, SDL_AUDIO_ALLOW_ANY_CHANGE); else mDeviceID = SDL_OpenAudioDevice(name, SDL_FALSE, &want, &have, SDL_AUDIO_ALLOW_ANY_CHANGE); } if(mDeviceID == 0) return ALC_INVALID_VALUE; mDevice->Frequency = static_cast(have.freq); if(have.channels == 1) mDevice->FmtChans = DevFmtMono; else if(have.channels == 2) mDevice->FmtChans = DevFmtStereo; else { ERR("Got unhandled SDL channel count: %d\n", int{have.channels}); return ALC_INVALID_VALUE; } switch(have.format) { case AUDIO_U8: mDevice->FmtType = DevFmtUByte; break; case AUDIO_S8: mDevice->FmtType = DevFmtByte; break; case AUDIO_U16SYS: mDevice->FmtType = DevFmtUShort; break; case AUDIO_S16SYS: mDevice->FmtType = DevFmtShort; break; case AUDIO_S32SYS: mDevice->FmtType = DevFmtInt; break; case AUDIO_F32SYS: mDevice->FmtType = DevFmtFloat; break; default: ERR("Got unsupported SDL format: 0x%04x\n", have.format); return ALC_INVALID_VALUE; } mDevice->UpdateSize = have.samples; mDevice->BufferSize = have.samples * 2; /* SDL always (tries to) use two periods. */ mFrameSize = mDevice->frameSizeFromFmt(); mFrequency = mDevice->Frequency; mFmtChans = mDevice->FmtChans; mFmtType = mDevice->FmtType; mUpdateSize = mDevice->UpdateSize; mDevice->DeviceName = name ? name : defaultDeviceName; return ALC_NO_ERROR; } bool Sdl2Backend::reset() { mDevice->Frequency = mFrequency; mDevice->FmtChans = mFmtChans; mDevice->FmtType = mFmtType; mDevice->UpdateSize = mUpdateSize; mDevice->BufferSize = mUpdateSize * 2; SetDefaultWFXChannelOrder(mDevice); return true; } bool Sdl2Backend::start() { SDL_PauseAudioDevice(mDeviceID, 0); return true; } void Sdl2Backend::stop() { SDL_PauseAudioDevice(mDeviceID, 1); } void Sdl2Backend::lock() { SDL_LockAudioDevice(mDeviceID); } void Sdl2Backend::unlock() { SDL_UnlockAudioDevice(mDeviceID); } } // namespace BackendFactory &SDL2BackendFactory::getFactory() { static SDL2BackendFactory factory{}; return factory; } bool SDL2BackendFactory::init() { return (SDL_InitSubSystem(SDL_INIT_AUDIO) == 0); } bool SDL2BackendFactory::querySupport(BackendType type) { return type == BackendType::Playback; } void SDL2BackendFactory::probe(DevProbe type, std::string *outnames) { if(type != DevProbe::Playback) return; int num_devices{SDL_GetNumAudioDevices(SDL_FALSE)}; /* Includes null char. */ outnames->append(defaultDeviceName, sizeof(defaultDeviceName)); for(int i{0};i < num_devices;++i) { std::string name{DEVNAME_PREFIX}; name += SDL_GetAudioDeviceName(i, SDL_FALSE); if(!name.empty()) outnames->append(name.c_str(), name.length()+1); } } BackendPtr SDL2BackendFactory::createBackend(ALCdevice *device, BackendType type) { if(type == BackendType::Playback) return BackendPtr{new Sdl2Backend{device}}; return nullptr; }