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Fix for the huge audio latency of the SamplePlayer (>200 ms)

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- fixes PulseAudio, ALSA and RtAudio driver
- cleans up the driver files for better readability (mostly whitespace-related stuff)
- makes ALSA and Pulseaudio actually use the global setting "audio/mix_rate" for the sample rate instead of a
fixed value (RtAudio did this already)
This commit is contained in:
lonesurvivor
2017-01-03 19:00:31 +01:00
parent 495d059a74
commit da6b6c2dd7
4 changed files with 145 additions and 131 deletions
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50
drivers/alsa/audio_driver_alsa.cpp
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@ -45,7 +45,7 @@ Error AudioDriverALSA::init() {
samples_in = NULL;
samples_out = NULL;
mix_rate = 44100;
mix_rate = GLOBAL_DEF("audio/mix_rate",44100);
output_format = OUTPUT_STEREO;
channels = 2;
@ -70,67 +70,62 @@ Error AudioDriverALSA::init() {
ERR_FAIL_COND_V( status<0, ERR_CANT_OPEN );
snd_pcm_hw_params_alloca(&hwparams);
status = snd_pcm_hw_params_any(pcm_handle, hwparams);
status = snd_pcm_hw_params_any(pcm_handle, hwparams);
CHECK_FAIL( status<0 );
status = snd_pcm_hw_params_set_access(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED);
CHECK_FAIL( status<0 );
//not interested in anything else
status = snd_pcm_hw_params_set_format(pcm_handle, hwparams, SND_PCM_FORMAT_S16_LE);
CHECK_FAIL( status<0 );
//todo: support 4 and 6
status = snd_pcm_hw_params_set_channels(pcm_handle, hwparams, 2);
CHECK_FAIL( status<0 );
status = snd_pcm_hw_params_set_rate_near(pcm_handle, hwparams, &mix_rate, NULL);
CHECK_FAIL( status<0 );
int latency = GLOBAL_DEF("audio/output_latency",25);
buffer_size = nearest_power_of_2( latency * mix_rate / 1000 );
status = snd_pcm_hw_params_set_period_size_near(pcm_handle, hwparams, &buffer_size, NULL);
// set buffer size from project settings
status = snd_pcm_hw_params_set_buffer_size_near(pcm_handle, hwparams, &buffer_size);
CHECK_FAIL( status<0 );
// make period size 1/8
period_size = buffer_size >> 3;
status = snd_pcm_hw_params_set_period_size_near(pcm_handle, hwparams, &period_size, NULL);
CHECK_FAIL( status<0 );
unsigned int periods=2;
status = snd_pcm_hw_params_set_periods_near(pcm_handle, hwparams, &periods, NULL);
CHECK_FAIL( status<0 );
status = snd_pcm_hw_params(pcm_handle,hwparams);
CHECK_FAIL( status<0 );
//snd_pcm_hw_params_free(&hwparams);
snd_pcm_sw_params_alloca(&swparams);
status = snd_pcm_sw_params_current(pcm_handle, swparams);
CHECK_FAIL( status<0 );
status = snd_pcm_sw_params_set_avail_min(pcm_handle, swparams, buffer_size);
status = snd_pcm_sw_params_set_avail_min(pcm_handle, swparams, period_size);
CHECK_FAIL( status<0 );
status = snd_pcm_sw_params_set_start_threshold(pcm_handle, swparams, 1);
CHECK_FAIL( status<0 );
status = snd_pcm_sw_params(pcm_handle, swparams);
CHECK_FAIL( status<0 );
samples_in = memnew_arr(int32_t, buffer_size*channels);
samples_out = memnew_arr(int16_t, buffer_size*channels);
samples_in = memnew_arr(int32_t, period_size*channels);
samples_out = memnew_arr(int16_t, period_size*channels);
snd_pcm_nonblock(pcm_handle, 0);
@ -144,36 +139,28 @@ void AudioDriverALSA::thread_func(void* p_udata) {
AudioDriverALSA* ad = (AudioDriverALSA*)p_udata;
while (!ad->exit_thread) {
if (!ad->active) {
for (unsigned int i=0; i < ad->buffer_size*ad->channels; i++) {
for (unsigned int i=0; i < ad->period_size*ad->channels; i++) {
ad->samples_out[i] = 0;
};
} else {
ad->lock();
ad->audio_server_process(ad->buffer_size, ad->samples_in);
ad->audio_server_process(ad->period_size, ad->samples_in);
ad->unlock();
for(unsigned int i=0;i<ad->buffer_size*ad->channels;i++) {
for(unsigned int i=0;i<ad->period_size*ad->channels;i++) {
ad->samples_out[i]=ad->samples_in[i]>>16;
}
};
int todo = ad->buffer_size; // * ad->channels * 2;
int todo = ad->period_size;
int total = 0;
while (todo) {
if (ad->exit_thread)
break;
uint8_t* src = (uint8_t*)ad->samples_out;
@ -184,7 +171,8 @@ void AudioDriverALSA::thread_func(void* p_udata) {
break;
if ( wrote == -EAGAIN ) {
usleep(1000); //can't write yet (though this is blocking..)
//can't write yet (though this is blocking..)
usleep(1000);
continue;
}
wrote = snd_pcm_recover(ad->pcm_handle, wrote, 0);
@ -197,9 +185,9 @@ void AudioDriverALSA::thread_func(void* p_udata) {
}
continue;
};
total += wrote;
todo -= wrote;
};
};