/* * OpenAL Audio Stream Example * * Copyright (c) 2011 by Chris Robinson * * 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 a relatively simple streaming audio player. */ #include #include #include #include #include #include "AL/al.h" #include "AL/alc.h" #include "AL/alext.h" #include "common/alhelpers.h" #include "common/sdl_sound.h" static LPALBUFFERSAMPLESSOFT alBufferSamplesSOFT = wrap_BufferSamples; static LPALISBUFFERFORMATSUPPORTEDSOFT alIsBufferFormatSupportedSOFT; /* Define the number of buffers and buffer size (in milliseconds) to use. 4 * buffers with 200ms each gives a nice per-chunk size, and lets the queue last * for almost one second. */ #define NUM_BUFFERS 4 #define BUFFER_TIME_MS 200 typedef struct StreamPlayer { /* These are the buffers and source to play out through OpenAL with */ ALuint buffers[NUM_BUFFERS]; ALuint source; /* Handle for the audio file */ FilePtr file; /* The format of the output stream */ ALenum format; ALenum channels; ALenum type; ALuint rate; } StreamPlayer; static StreamPlayer *NewPlayer(void); static void DeletePlayer(StreamPlayer *player); static int OpenPlayerFile(StreamPlayer *player, const char *filename); static void ClosePlayerFile(StreamPlayer *player); static int StartPlayer(StreamPlayer *player); static int UpdatePlayer(StreamPlayer *player); /* Creates a new player object, and allocates the needed OpenAL source and * buffer objects. Error checking is simplified for the purposes of this * example, and will cause an abort if needed. */ static StreamPlayer *NewPlayer(void) { StreamPlayer *player; player = malloc(sizeof(*player)); assert(player != NULL); memset(player, 0, sizeof(*player)); /* Generate the buffers and source */ alGenBuffers(NUM_BUFFERS, player->buffers); assert(alGetError() == AL_NO_ERROR && "Could not create buffers"); alGenSources(1, &player->source); assert(alGetError() == AL_NO_ERROR && "Could not create source"); /* Set parameters so mono sources play out the front-center speaker and * won't distance attenuate. */ alSource3i(player->source, AL_POSITION, 0, 0, -1); alSourcei(player->source, AL_SOURCE_RELATIVE, AL_TRUE); alSourcei(player->source, AL_ROLLOFF_FACTOR, 0); assert(alGetError() == AL_NO_ERROR && "Could not set source parameters"); return player; } /* Destroys a player object, deleting the source and buffers. No error handling * since these calls shouldn't fail with a properly-made player object. */ static void DeletePlayer(StreamPlayer *player) { ClosePlayerFile(player); alDeleteSources(1, &player->source); alDeleteBuffers(NUM_BUFFERS, player->buffers); if(alGetError() != AL_NO_ERROR) fprintf(stderr, "Failed to delete object IDs\n"); memset(player, 0, sizeof(*player)); free(player); } /* Opens the first audio stream of the named file. If a file is already open, * it will be closed first. */ static int OpenPlayerFile(StreamPlayer *player, const char *filename) { ClosePlayerFile(player); /* Open the file and get the first stream from it */ player->file = openAudioFile(filename, BUFFER_TIME_MS); if(!player->file) { fprintf(stderr, "Could not open audio in %s\n", filename); goto error; } /* Get the stream format, and figure out the OpenAL format */ if(getAudioInfo(player->file, &player->rate, &player->channels, &player->type) != 0) { fprintf(stderr, "Error getting audio info for %s\n", filename); goto error; } player->format = GetFormat(player->channels, player->type, alIsBufferFormatSupportedSOFT); if(player->format == 0) { fprintf(stderr, "Unsupported format (%s, %s) for %s\n", ChannelsName(player->channels), TypeName(player->type), filename); goto error; } return 1; error: closeAudioFile(player->file); player->file = NULL; return 0; } /* Closes the audio file stream */ static void ClosePlayerFile(StreamPlayer *player) { closeAudioFile(player->file); player->file = NULL; } /* Prebuffers some audio from the file, and starts playing the source */ static int StartPlayer(StreamPlayer *player) { size_t i; /* Rewind the source position and clear the buffer queue */ alSourceRewind(player->source); alSourcei(player->source, AL_BUFFER, 0); /* Fill the buffer queue */ for(i = 0;i < NUM_BUFFERS;i++) { uint8_t *data; size_t got; /* Get some data to give it to the buffer */ data = getAudioData(player->file, &got); if(!data) break; alBufferSamplesSOFT(player->buffers[i], player->rate, player->format, BytesToFrames(got, player->channels, player->type), player->channels, player->type, data); } if(alGetError() != AL_NO_ERROR) { fprintf(stderr, "Error buffering for playback\n"); return 0; } /* Now queue and start playback! */ alSourceQueueBuffers(player->source, i, player->buffers); alSourcePlay(player->source); if(alGetError() != AL_NO_ERROR) { fprintf(stderr, "Error starting playback\n"); return 0; } return 1; } static int UpdatePlayer(StreamPlayer *player) { ALint processed, state; /* Get relevant source info */ alGetSourcei(player->source, AL_SOURCE_STATE, &state); alGetSourcei(player->source, AL_BUFFERS_PROCESSED, &processed); if(alGetError() != AL_NO_ERROR) { fprintf(stderr, "Error checking source state\n"); return 0; } /* Unqueue and handle each processed buffer */ while(processed > 0) { ALuint bufid; uint8_t *data; size_t got; alSourceUnqueueBuffers(player->source, 1, &bufid); processed--; /* Read the next chunk of data, refill the buffer, and queue it * back on the source */ data = getAudioData(player->file, &got); if(data != NULL) { alBufferSamplesSOFT(bufid, player->rate, player->format, BytesToFrames(got, player->channels, player->type), player->channels, player->type, data); alSourceQueueBuffers(player->source, 1, &bufid); } if(alGetError() != AL_NO_ERROR) { fprintf(stderr, "Error buffering data\n"); return 0; } } /* Make sure the source hasn't underrun */ if(state != AL_PLAYING && state != AL_PAUSED) { ALint queued; /* If no buffers are queued, playback is finished */ alGetSourcei(player->source, AL_BUFFERS_QUEUED, &queued); if(queued == 0) return 0; alSourcePlay(player->source); if(alGetError() != AL_NO_ERROR) { fprintf(stderr, "Error restarting playback\n"); return 0; } } return 1; } int main(int argc, char **argv) { StreamPlayer *player; int i; /* Print out usage if no file was specified */ if(argc < 2) { fprintf(stderr, "Usage: %s \n", argv[0]); return 1; } if(InitAL() != 0) return 1; if(alIsExtensionPresent("AL_SOFT_buffer_samples")) { printf("AL_SOFT_buffer_samples supported!\n"); alBufferSamplesSOFT = alGetProcAddress("alBufferSamplesSOFT"); alIsBufferFormatSupportedSOFT = alGetProcAddress("alIsBufferFormatSupportedSOFT"); } else printf("AL_SOFT_buffer_samples not supported\n"); player = NewPlayer(); /* Play each file listed on the command line */ for(i = 1;i < argc;i++) { const char *namepart; if(!OpenPlayerFile(player, argv[i])) continue; /* Get the name portion, without the path, for display. */ namepart = strrchr(argv[i], '/'); if(namepart || (namepart=strrchr(argv[i], '\\'))) namepart++; else namepart = argv[i]; printf("Playing: %s (%s, %s, %dhz)\n", namepart, TypeName(player->type), ChannelsName(player->channels), player->rate); fflush(stdout); if(!StartPlayer(player)) { ClosePlayerFile(player); continue; } while(UpdatePlayer(player)) al_nssleep(10000000); /* All done with this file. Close it and go to the next */ ClosePlayerFile(player); } printf("Done.\n"); /* All files done. Delete the player, and close OpenAL */ DeletePlayer(player); player = NULL; CloseAL(); return 0; }