int openal_stream_init(audio_stream *stream, audio_sink *sink) {
openal_stream *local = malloc(sizeof(openal_stream));
// Dump old errors
int error;
while((error = alGetError()) != AL_NO_ERROR);
// Pick format
local->format = 0;
switch(source_get_bytes(stream->src)) {
case 1: switch(source_get_channels(stream->src)) {
case 1: local->format = AL_FORMAT_MONO8; break;
case 2: local->format = AL_FORMAT_STEREO8; break;
}; break;
case 2: switch(source_get_channels(stream->src)) {
case 1: local->format = AL_FORMAT_MONO16; break;
case 2: local->format = AL_FORMAT_STEREO16; break;
}; break;
};
if(!local->format) {
PERROR("OpenAL Stream: Could not find suitable audio format!");
goto exit_0;
}
// Generate a source
alGenSources(1, &local->source);
if(alGetError() != AL_NO_ERROR) {
PERROR("OpenAL Stream: Could not create audio source!");
goto exit_0;
}
// Generate buffers
alGenBuffers(AUDIO_BUFFER_COUNT, local->buffers);
if(alGetError() != AL_NO_ERROR) {
PERROR("OpenAL Stream: Could not create audio buffers!");
goto exit_1;
}
// Set callbacks etc.
stream_set_userdata(stream, local);
stream_set_update_cb(stream, openal_stream_update);
stream_set_close_cb(stream, openal_stream_close);
stream_set_play_cb(stream, openal_stream_play);
stream_set_stop_cb(stream, openal_stream_stop);
stream_set_apply_cb(stream, openal_stream_apply);
// All done
return 0;
// Error exits
exit_1:
alDeleteSources(1, &local->source);
exit_0:
free(local);
return 1;
}
int dumb_source_update(audio_source *src, char *buffer, int len) {
dumb_source *local = source_get_userdata(src);
// Get deltatime and bitrate
float delta = 65536.0f / source_get_frequency(src);
int bps = source_get_channels(src) * source_get_bytes(src);
// If looping is off, and if we have played the whole file, stop here.
long pos = duh_sigrenderer_get_position(local->renderer);
if(pos < local->vpos && !src->loop) {
return 0;
}
local->vpos = pos;
// ... otherwise get more data.
int ret = duh_render_int(
local->renderer,
&local->sig_samples,
&local->sig_samples_size,
source_get_bytes(src) * 8, // Bits
0, // Unsign
1.0f, // Volume
delta,
len / bps, // Size
buffer
) * bps;
return ret;
}
void openal_stream_apply(audio_stream *stream) {
openal_stream *local = stream_get_userdata(stream);
// Handle panning here (only if mono)
if(source_get_channels(stream->src) == 1) {
float pos[] = {stream->panning, 0.0f, -1.0f};
alSourcefv(local->source, AL_POSITION, pos);
}
// Volume and pitch
alSourcef(local->source, AL_GAIN, stream->volume);
alSourcef(local->source, AL_PITCH, stream->pitch);
}
