diff options
| -rw-r--r-- | CMakeLists.txt | 7 | ||||
| -rw-r--r-- | examples/alloopback.c | 244 |
2 files changed, 250 insertions, 1 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt index 07aa66d7..4efd396c 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -882,7 +882,12 @@ IF(ALSOFT_EXAMPLES) TARGET_LINK_LIBRARIES(allatency ex-common ${SDL_SOUND_LIBRARIES} ${LIBNAME}) SET_TARGET_PROPERTIES(allatency PROPERTIES INCLUDE_DIRECTORIES "${SDL_SOUND_INCLUDE_DIR}") - INSTALL(TARGETS alstream alreverb allatency + ADD_EXECUTABLE(alloopback examples/alloopback.c) + TARGET_LINK_LIBRARIES(alloopback ex-common ${SDL_SOUND_LIBRARIES} ${SDL_LIBRARIES} ${LIBNAME}) + SET_TARGET_PROPERTIES(alloopback PROPERTIES INCLUDE_DIRECTORIES "${SDL_INCLUDE_DIR}" + INCLUDE_DIRECTORIES "${SDL_SOUND_INCLUDE_DIR}") + + INSTALL(TARGETS alstream alreverb allatency alloopback RUNTIME DESTINATION bin LIBRARY DESTINATION "lib${LIB_SUFFIX}" ARCHIVE DESTINATION "lib${LIB_SUFFIX}" diff --git a/examples/alloopback.c b/examples/alloopback.c new file mode 100644 index 00000000..649ef6ef --- /dev/null +++ b/examples/alloopback.c @@ -0,0 +1,244 @@ +/* + * OpenAL Loopback Example + * + * Copyright (c) 2013 by Chris Robinson <[email protected]> + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +/* This file contains an example for using the loopback device for custom + * output handling. + */ + +#include <stdio.h> +#include <assert.h> +#include <math.h> + +#include <SDL.h> + +#include "AL/al.h" +#include "AL/alc.h" +#include "AL/alext.h" + +#include "common/alhelpers.h" + +#ifndef M_PI +#define M_PI (3.14159265358979323846) +#endif + +typedef struct { + ALCdevice *Device; + ALCcontext *Context; + + ALCsizei FrameSize; +} PlaybackInfo; + +static LPALCLOOPBACKOPENDEVICESOFT alcLoopbackOpenDeviceSOFT; +static LPALCISRENDERFORMATSUPPORTEDSOFT alcIsRenderFormatSupportedSOFT; +static LPALCRENDERSAMPLESSOFT alcRenderSamplesSOFT; + + +void SDLCALL RenderSDLSamples(void *userdata, Uint8 *stream, int len) +{ + PlaybackInfo *playback = (PlaybackInfo*)userdata; + alcRenderSamplesSOFT(playback->Device, stream, len/playback->FrameSize); +} + + +/* Creates a one second buffer containing a sine wave, and returns the new + * buffer ID. */ +static ALuint CreateSineWave(void) +{ + ALshort data[44100]; + ALuint buffer; + ALenum err; + ALuint i; + + for(i = 0;i < 44100;i++) + data[i] = (ALshort)(sin(i * 441.0 / 44100.0 * 2.0*M_PI)*32767.0); + + /* Buffer the audio data into a new buffer object. */ + buffer = 0; + alGenBuffers(1, &buffer); + alBufferData(buffer, AL_FORMAT_MONO16, data, sizeof(data), 44100); + + /* Check if an error occured, and clean up if so. */ + err = alGetError(); + if(err != AL_NO_ERROR) + { + fprintf(stderr, "OpenAL Error: %s\n", alGetString(err)); + if(alIsBuffer(buffer)) + alDeleteBuffers(1, &buffer); + return 0; + } + + return buffer; +} + + +int main() +{ + PlaybackInfo playback = { NULL, NULL, 0 }; + SDL_AudioSpec desired, obtained; + ALuint source, buffer; + ALCint attrs[16]; + ALenum state; + + /* Print out error if extension is missing. */ + if(!alcIsExtensionPresent(NULL, "ALC_SOFT_loopback")) + { + fprintf(stderr, "Error: ALC_SOFT_loopback not supported!\n"); + return 1; + } + + /* Define a macro to help load the function pointers. */ +#define LOAD_PROC(x) ((x) = alcGetProcAddress(NULL, #x)) + LOAD_PROC(alcLoopbackOpenDeviceSOFT); + LOAD_PROC(alcIsRenderFormatSupportedSOFT); + LOAD_PROC(alcRenderSamplesSOFT); +#undef LOAD_PROC + + if(SDL_Init(SDL_INIT_AUDIO) == -1) + { + fprintf(stderr, "Failed to init SDL audio: %s\n", SDL_GetError()); + return 1; + } + + /* Set up SDL audio with our requested format and callback. */ + desired.channels = 2; + desired.format = AUDIO_S16SYS; + desired.freq = 44100; + desired.padding = 0; + desired.samples = 4096; + desired.callback = RenderSDLSamples; + desired.userdata = &playback; + if(SDL_OpenAudio(&desired, &obtained) != 0) + { + SDL_Quit(); + fprintf(stderr, "Failed to open SDL audio: %s\n", SDL_GetError()); + return 1; + } + + /* Set up our OpenAL attributes based on what we got from SDL. */ + attrs[0] = ALC_FORMAT_CHANNELS_SOFT; + if(obtained.channels == 1) + attrs[1] = ALC_MONO_SOFT; + else if(obtained.channels == 2) + attrs[1] = ALC_STEREO_SOFT; + else + { + fprintf(stderr, "Unhandled SDL channel count: %d\n", obtained.channels); + goto error; + } + + attrs[2] = ALC_FORMAT_TYPE_SOFT; + if(obtained.format == AUDIO_U8) + attrs[3] = ALC_UNSIGNED_BYTE_SOFT; + else if(obtained.format == AUDIO_S8) + attrs[3] = ALC_BYTE_SOFT; + else if(obtained.format == AUDIO_U16SYS) + attrs[3] = ALC_UNSIGNED_SHORT_SOFT; + else if(obtained.format == AUDIO_S16SYS) + attrs[3] = ALC_SHORT_SOFT; + else + { + fprintf(stderr, "Unhandled SDL format: 0x%04x\n", obtained.format); + goto error; + } + + attrs[4] = ALC_FREQUENCY; + attrs[5] = obtained.freq; + + attrs[6] = 0; /* end of list */ + + /* Initialize OpenAL loopback device, using our format attributes. */ + playback.Device = alcLoopbackOpenDeviceSOFT(NULL); + if(!playback.Device) + { + fprintf(stderr, "Failed to open loopback device!\n"); + goto error; + } + /* Make sure the format is supported before setting them on the device. */ + if(alcIsRenderFormatSupportedSOFT(playback.Device, attrs[5], attrs[1], attrs[3]) == ALC_FALSE) + { + fprintf(stderr, "Render format not supported: %s, %s, %dhz\n", + ChannelsName(attrs[1]), TypeName(attrs[3]), attrs[5]); + goto error; + } + playback.Context = alcCreateContext(playback.Device, attrs); + if(!playback.Context || alcMakeContextCurrent(playback.Context) == ALC_FALSE) + { + fprintf(stderr, "Failed to set an OpenAL audio context\n"); + goto error; + } + playback.FrameSize = FramesToBytes(1, attrs[1], attrs[3]); + + /* Start SDL playing. Our callback (thus alcRenderSamplesSOFT) will now + * start being called regularly to update the AL playback state. */ + SDL_PauseAudio(0); + + /* Load the sound into a buffer. */ + buffer = CreateSineWave(); + if(!buffer) + { + SDL_CloseAudio(); + alcDestroyContext(playback.Context); + alcCloseDevice(playback.Device); + SDL_Quit(); + return 1; + } + + /* Create the source to play the sound with. */ + source = 0; + alGenSources(1, &source); + alSourcei(source, AL_BUFFER, buffer); + assert(alGetError()==AL_NO_ERROR && "Failed to setup sound source"); + + /* Play the sound until it finishes. */ + alSourcePlay(source); + do { + Sleep(10); + alGetSourcei(source, AL_SOURCE_STATE, &state); + } while(alGetError() == AL_NO_ERROR && state == AL_PLAYING); + + /* All done. Delete resources, and close OpenAL. */ + alDeleteSources(1, &source); + alDeleteBuffers(1, &buffer); + + /* Stop SDL playing. */ + SDL_PauseAudio(1); + + /* Close up OpenAL and SDL. */ + SDL_CloseAudio(); + alcDestroyContext(playback.Context); + alcCloseDevice(playback.Device); + SDL_Quit(); + + return 0; + +error: + SDL_CloseAudio(); + if(playback.Context) + alcDestroyContext(playback.Context); + if(playback.Device) + alcCloseDevice(playback.Device); + SDL_Quit(); + + return 1; +} |