/* * 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 */voidaudiodevopen(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");} voidaudiodevclose(void){	snd_pcm_drain(playback);	snd_pcm_close(playback); 	snd_pcm_close(capture);} voidaudiodevsetvol(int what, int left, int right){	if(what == Vspeed){		speed = left;		return;	}} voidaudiodevgetvol(int what, int *left, int *right){	if(what == Vspeed){		*left = *right = speed;		return;	} 	*left = *right = 100;} intaudiodevwrite(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;} intaudiodevread(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;}