godot/drivers/pulseaudio/audio_driver_pulseaudio.cpp

/*************************************************************************/
/*  audio_driver_alsa.cpp                                                */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur.                 */
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#include "audio_driver_pulseaudio.h"

#ifdef PULSEAUDIO_ENABLED

#include <pulse/error.h>

#include "globals.h"

Error AudioDriverPulseAudio::init() {

    active = false;
    thread_exited = false;
    exit_thread = false;
	pcm_open = false;
	samples_in = NULL;
	samples_out = NULL;

	mix_rate = 44100;
	output_format = OUTPUT_STEREO;
	channels = 2;

    pa_sample_spec spec;
    spec.format = PA_SAMPLE_S16LE;
    spec.channels = channels;
    spec.rate = mix_rate;

    int error_code;
    pulse = pa_simple_new(NULL,         // default server
                          "Godot",      // application name
                          PA_STREAM_PLAYBACK,
                          NULL,         // default device
                          "Sound",      // stream description
                          &spec,
                          NULL,         // use default channel map
                          NULL,         // use default buffering attributes
                          &error_code
                          );

    if (pulse == NULL) {

        fprintf(stderr, "PulseAudio ERR: %s\n", pa_strerror(error_code));\
        ERR_FAIL_COND_V(pulse == NULL, ERR_CANT_OPEN);
    }

    int latency = GLOBAL_DEF("audio/output_latency", 25);
    buffer_size = nearest_power_of_2(latency * mix_rate / 1000);

    samples_in = memnew_arr(int32_t, buffer_size * channels);
    samples_out = memnew_arr(int16_t, buffer_size * channels);

    mutex = Mutex::create();
    thread = Thread::create(AudioDriverPulseAudio::thread_func, this);

	return OK;
}

float AudioDriverPulseAudio::get_latency() {

	if (latency==0)	{ //only do this once since it's approximate anyway
		int error_code;
		pa_usec_t palat = pa_simple_get_latency( pulse,&error_code);
		latency=double(palat)/1000000.0;
	}

	return latency;
}

void AudioDriverPulseAudio::thread_func(void* p_udata) {

    AudioDriverPulseAudio* ad = (AudioDriverPulseAudio*)p_udata;

	while (!ad->exit_thread) {

		if (!ad->active) {

            for (unsigned int i=0; i < ad->buffer_size * ad->channels; i++) {

				ad->samples_out[i] = 0;
            }

		} else {

			ad->lock();

			ad->audio_server_process(ad->buffer_size, ad->samples_in);

			ad->unlock();

            for (unsigned int i=0; i < ad->buffer_size * ad->channels;i ++) {

                ad->samples_out[i] = ad->samples_in[i] >> 16;
			}
        }

        // pa_simple_write always consumes the entire buffer

        int error_code;
        int byte_size = ad->buffer_size * sizeof(int16_t) * ad->channels;
        if (pa_simple_write(ad->pulse, ad->samples_out, byte_size, &error_code) < 0) {

            // can't recover here
            fprintf(stderr, "PulseAudio failed and can't recover: %s\n", pa_strerror(error_code));
            ad->active = false;
            ad->exit_thread = true;
            break;
        }

    }

    ad->thread_exited = true;
}

void AudioDriverPulseAudio::start() {

	active = true;
}

int AudioDriverPulseAudio::get_mix_rate() const {

	return mix_rate;
}

AudioDriverSW::OutputFormat AudioDriverPulseAudio::get_output_format() const {

	return output_format;
}

void AudioDriverPulseAudio::lock() {

	if (!thread || !mutex)
		return;
	mutex->lock();
}

void AudioDriverPulseAudio::unlock() {

	if (!thread || !mutex)
		return;
	mutex->unlock();
}

void AudioDriverPulseAudio::finish() {

	if (!thread)
		return;

	exit_thread = true;
	Thread::wait_to_finish(thread);

    if (pulse)
        pa_simple_free(pulse);

	if (samples_in) {
		memdelete_arr(samples_in);
		memdelete_arr(samples_out);
	};

	memdelete(thread);
    if (mutex) {
		memdelete(mutex);
        mutex = NULL;
    }

	thread = NULL;
}

AudioDriverPulseAudio::AudioDriverPulseAudio() {

	mutex = NULL;
    thread = NULL;
    pulse = NULL;
    latency=0;
}

AudioDriverPulseAudio::~AudioDriverPulseAudio() {

}

#endif