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/*
* ALSA
*/
#include <alsa/asoundlib.h>
#include "u.h"
#include "lib.h"
#include "dat.h"
#include "fns.h"
#include "error.h"
#include "devaudio.h"
enum
{
Channels = 2,
Rate = 44100,
Bits = 16,
};
static snd_pcm_t *playback;
static snd_pcm_t *capture;
static int speed = Rate;
/* maybe this should return -1 instead of sysfatal */
void
audiodevopen(void)
{
if(snd_pcm_open(&playback, "default", SND_PCM_STREAM_PLAYBACK, 0) < 0)
error("snd_pcm_open playback");
if(snd_pcm_set_params(playback, SND_PCM_FORMAT_S16_LE, SND_PCM_ACCESS_RW_INTERLEAVED, 2, speed, 1, 500000) < 0)
error("snd_pcm_set_params playback");
if(snd_pcm_prepare(playback) < 0)
error("snd_pcm_prepare playback");
if(snd_pcm_open(&capture, "default", SND_PCM_STREAM_CAPTURE, 0) < 0)
error("snd_pcm_open capture");
if(snd_pcm_set_params(capture, SND_PCM_FORMAT_S16_LE, SND_PCM_ACCESS_RW_INTERLEAVED, 2, speed, 1, 500000) < 0)
error("snd_pcm_set_params capture");
if(snd_pcm_prepare(capture) < 0)
error("snd_pcm_prepare capture");
}
void
audiodevclose(void)
{
snd_pcm_drain(playback);
snd_pcm_close(playback);
snd_pcm_close(capture);
}
void
audiodevsetvol(int what, int left, int right)
{
if(what == Vspeed){
speed = left;
return;
}
}
void
audiodevgetvol(int what, int *left, int *right)
{
if(what == Vspeed){
*left = *right = speed;
return;
}
*left = *right = 100;
}
int
audiodevwrite(void *v, int n)
{
snd_pcm_sframes_t frames;
int tot, m;
for(tot = 0; tot < n; tot += m){
do {
frames = snd_pcm_writei(playback, v+tot, (n-tot)/4);
} while(frames == -EAGAIN);
if (frames < 0)
frames = snd_pcm_recover(playback, frames, 0);
if (frames < 0)
error((char*)snd_strerror(frames));
m = frames*4;
}
return tot;
}
int
audiodevread(void *v, int n)
{
snd_pcm_sframes_t frames;
do {
frames = snd_pcm_readi(capture, v, n/4);
} while(frames == -EAGAIN);
if (frames < 0)
error((char*)snd_strerror(frames));
return frames*4;
}
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