/**
* @brief Handle audio output
*/
void OpenAL2::doOutput()
{
alcMakeContextCurrent(alOutContext);
ALuint bufids[PROXY_BUFFER_COUNT];
ALint processed = 0, queued = 0;
alGetSourcei(alProxySource, AL_BUFFERS_PROCESSED, &processed);
alGetSourcei(alProxySource, AL_BUFFERS_QUEUED, &queued);
if (processed > 0) {
// unqueue all processed buffers
alSourceUnqueueBuffers(alProxySource, processed, bufids);
// delete all but the first buffer, reuse first for new data
alDeleteBuffers(processed - 1, bufids + 1);
} else if (queued < PROXY_BUFFER_COUNT) {
// create new buffer until the maximum is reached
alGenBuffers(1, bufids);
} else {
alcMakeContextCurrent(alProxyContext);
return;
}
ALdouble latency[2] = {0};
alGetSourcedvSOFT(alProxySource, AL_SEC_OFFSET_LATENCY_SOFT, latency);
checkAlError();
ALshort outBuf[AUDIO_FRAME_SAMPLE_COUNT] = {0};
alcMakeContextCurrent(alProxyContext);
alcRenderSamplesSOFT(alProxyDev, outBuf, AUDIO_FRAME_SAMPLE_COUNT);
checkAlcError(alProxyDev);
alcMakeContextCurrent(alOutContext);
alBufferData(bufids[0], AL_FORMAT_MONO16, outBuf, AUDIO_FRAME_SAMPLE_COUNT * 2, AUDIO_SAMPLE_RATE);
alSourceQueueBuffers(alProxySource, 1, bufids);
// initialize echo canceler if supported
if (!filterer) {
filterer = new_filter_audio(AUDIO_SAMPLE_RATE);
int16_t filterLatency = latency[1] * 1000 * 2 + AUDIO_FRAME_DURATION;
qDebug() << "Setting filter delay to: " << filterLatency << "ms";
set_echo_delay_ms(filterer, filterLatency);
enable_disable_filters(filterer, 1, 1, 1, 0);
}
// do echo cancel
pass_audio_output(filterer, outBuf, AUDIO_FRAME_SAMPLE_COUNT);
ALint state;
alGetSourcei(alProxySource, AL_SOURCE_STATE, &state);
if (state != AL_PLAYING) {
qDebug() << "Proxy source underflow detected";
alSourcePlay(alProxySource);
}
alcMakeContextCurrent(alProxyContext);
}
/* Enable/disable filters. 1 to enable, 0 to disable. */
bool AudioFilterer::enableDisableFilters(int echo, int noise, int gain)
{
return filter && 0 == enable_disable_filters(filter, echo, noise, gain);
}
