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/**
* @file alsa.c ALSA sound driver
*
* Copyright (C) 2010 Creytiv.com
*/
#define _POSIX_SOURCE 1
#include <sys/types.h>
#include <sys/time.h>
#include <stdlib.h>
#include <unistd.h>
#include <alsa/asoundlib.h>
#include <re.h>
#include <rem.h>
#include <baresip.h>
#include "alsa.h"
/**
* @defgroup alsa alsa
*
* Advanced Linux Sound Architecture (ALSA) audio driver module
*
*
* References:
*
* http://www.alsa-project.org/main/index.php/Main_Page
*/
char alsa_dev[64] = "default";
static struct ausrc *ausrc;
static struct auplay *auplay;
int alsa_reset(snd_pcm_t *pcm, uint32_t srate, uint32_t ch,
uint32_t num_frames)
{
snd_pcm_hw_params_t *hw_params = NULL;
const snd_pcm_format_t pcmfmt = SND_PCM_FORMAT_S16;
snd_pcm_uframes_t period = num_frames, bufsize = num_frames * 4;
int err;
err = snd_pcm_hw_params_malloc(&hw_params);
if (err < 0) {
warning("alsa: cannot allocate hw params (%s)\n",
snd_strerror(err));
goto out;
}
err = snd_pcm_hw_params_any(pcm, hw_params);
if (err < 0) {
warning("alsa: cannot initialize hw params (%s)\n",
snd_strerror(err));
goto out;
}
err = snd_pcm_hw_params_set_access(pcm, hw_params,
SND_PCM_ACCESS_RW_INTERLEAVED);
if (err < 0) {
warning("alsa: cannot set access type (%s)\n",
snd_strerror(err));
goto out;
}
err = snd_pcm_hw_params_set_format(pcm, hw_params, pcmfmt);
if (err < 0) {
warning("alsa: cannot set sample format %d (%s)\n",
pcmfmt, snd_strerror(err));
goto out;
}
err = snd_pcm_hw_params_set_rate(pcm, hw_params, srate, 0);
if (err < 0) {
warning("alsa: cannot set sample rate to %u Hz (%s)\n",
srate, snd_strerror(err));
goto out;
}
err = snd_pcm_hw_params_set_channels(pcm, hw_params, ch);
if (err < 0) {
warning("alsa: cannot set channel count to %d (%s)\n",
ch, snd_strerror(err));
goto out;
}
err = snd_pcm_hw_params_set_period_size_near(pcm, hw_params,
&period, 0);
if (err < 0) {
warning("alsa: cannot set period size to %d (%s)\n",
period, snd_strerror(err));
}
err = snd_pcm_hw_params_set_buffer_size_near(pcm, hw_params, &bufsize);
if (err < 0) {
warning("alsa: cannot set buffer size to %d (%s)\n",
bufsize, snd_strerror(err));
}
err = snd_pcm_hw_params(pcm, hw_params);
if (err < 0) {
warning("alsa: cannot set parameters (%s)\n",
snd_strerror(err));
goto out;
}
err = snd_pcm_prepare(pcm);
if (err < 0) {
warning("alsa: cannot prepare audio interface for use (%s)\n",
snd_strerror(err));
goto out;
}
err = 0;
out:
snd_pcm_hw_params_free(hw_params);
if (err) {
warning("alsa: init failed: err=%d\n", err);
}
return err;
}
static int alsa_init(void)
{
int err;
err = ausrc_register(&ausrc, "alsa", alsa_src_alloc);
err |= auplay_register(&auplay, "alsa", alsa_play_alloc);
return err;
}
static int alsa_close(void)
{
ausrc = mem_deref(ausrc);
auplay = mem_deref(auplay);
return 0;
}
const struct mod_export DECL_EXPORTS(alsa) = {
"alsa",
"sound",
alsa_init,
alsa_close
};
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