flycast/core/oslib/alsa_audiostream.cpp

#include "audiostream.h"
#include "oslib/oslib.h"

#include "cfg/cfg.h"

#if HOST_OS==OS_LINUX && !defined(TARGET_NACL32) && !defined(ANDROID)

#if 1
#include <alsa/asoundlib.h>
#include <pthread.h>

snd_pcm_t *handle;

u32 alsa_Push(void* frame, u32 samples, bool wait) {
	
	snd_pcm_nonblock(handle, wait ? 0 : 1);

	int rc = snd_pcm_writei(handle, frame, samples);
	if (rc == -EPIPE)
	{
		/* EPIPE means underrun */
		fprintf(stderr, "ALSA: underrun occurred\n");
		snd_pcm_prepare(handle);
		alsa_Push(frame, samples * 8, wait);
	}
	else if (rc < 0)
	{
		fprintf(stderr, "ALSA: error from writei: %s\n", snd_strerror(rc));
	}
	else if (rc != samples)
	{
		fprintf(stderr, "ALSA: short write, wrote %d frames of %d\n", rc, samples);
	}
	return 1;
}
#if 0
u8 Tempbuffer[8192*4];
void* AudioThread(void*)
{
	sched_param sched;
	int policy;
	
	pthread_getschedparam(pthread_self(),&policy,&sched);
	sched.sched_priority++;//policy=SCHED_RR;
	pthread_setschedparam(pthread_self(),policy,&sched);

	for(;;)
	{
		UpdateBuff(Tempbuffer);
		int rc = snd_pcm_writei(handle, Tempbuffer, settings.aica.BufferSize);
		if (rc == -EPIPE)
		{
			/* EPIPE means underrun */
			fprintf(stderr, "underrun occurred\n");
			snd_pcm_prepare(handle);
		}
		else if (rc < 0)
		{
			fprintf(stderr, "error from writei: %s\n", snd_strerror(rc));
		}
		else if (rc != (int)settings.aica.BufferSize)
		{
			fprintf(stderr, "short write, write %d frames\n", rc);
		}
	}
}

cThread aud_thread(AudioThread,0);
#endif

void os_InitAudio()
{

	if (cfgLoadInt("audio","disable",0))
		return;

	cfgSaveInt("audio","disable",0);

	long loops;
	int size;

	snd_pcm_hw_params_t *params;
	unsigned int val;
	int dir;
	snd_pcm_uframes_t frames;

	/* Open PCM device for playback. */
	int rc = snd_pcm_open(&handle, "default", SND_PCM_STREAM_PLAYBACK, 0);

	if (rc<0)
		rc = snd_pcm_open(&handle, "plughw:0,0,0", SND_PCM_STREAM_PLAYBACK, 0);

	if (rc<0)
		rc = snd_pcm_open(&handle, "plughw:0,0", SND_PCM_STREAM_PLAYBACK, 0);

	if (rc < 0)
	{
		fprintf(stderr, "unable to open PCM device: %s\n", snd_strerror(rc));
		return;
	}

	/* Allocate a hardware parameters object. */
	snd_pcm_hw_params_alloca(&params);

	/* Fill it in with default values. */
	rc=snd_pcm_hw_params_any(handle, params);
	if (rc < 0)
	{
		fprintf(stderr, "Error:snd_pcm_hw_params_any %s\n", snd_strerror(rc));
		return;
	}

	/* Set the desired hardware parameters. */

	/* Interleaved mode */
	rc=snd_pcm_hw_params_set_access(handle, params, SND_PCM_ACCESS_RW_INTERLEAVED);
	if (rc < 0)
	{
		fprintf(stderr, "Error:snd_pcm_hw_params_set_access %s\n", snd_strerror(rc));
		return;
	}

	/* Signed 16-bit little-endian format */
	rc=snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_S16_LE);
	if (rc < 0)
	{
		fprintf(stderr, "Error:snd_pcm_hw_params_set_format %s\n", snd_strerror(rc));
		return;
	}

	/* Two channels (stereo) */
	rc=snd_pcm_hw_params_set_channels(handle, params, 2);
	if (rc < 0)
	{
		fprintf(stderr, "Error:snd_pcm_hw_params_set_channels %s\n", snd_strerror(rc));
		return;
	}

	/* 44100 bits/second sampling rate (CD quality) */
	val = 44100;
	rc=snd_pcm_hw_params_set_rate_near(handle, params, &val, &dir);
	if (rc < 0)
	{
		fprintf(stderr, "Error:snd_pcm_hw_params_set_rate_near %s\n", snd_strerror(rc));
		return;
	}

	/* Set period size to settings.aica.BufferSize frames. */
	frames = 2 * 1024;//settings.aica.BufferSize;
	rc=snd_pcm_hw_params_set_period_size_near(handle, params, &frames, &dir);
	if (rc < 0)
	{
		fprintf(stderr, "Error:snd_pcm_hw_params_set_buffer_size_near %s\n", snd_strerror(rc));
		return;
	}
	frames*=4;
	rc=snd_pcm_hw_params_set_buffer_size_near(handle, params, &frames);
	if (rc < 0)
	{
		fprintf(stderr, "Error:snd_pcm_hw_params_set_buffer_size_near %s\n", snd_strerror(rc));
		return;
	}

	/* Write the parameters to the driver */
	rc = snd_pcm_hw_params(handle, params);
	if (rc < 0)
	{
		fprintf(stderr, "Unable to set hw parameters: %s\n", snd_strerror(rc));
		return;
	}
}

void os_TermAudio()
{
	snd_pcm_drain(handle);
	snd_pcm_close(handle);
}
#else

#endif
#endif