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#include "audio-api.h"
#include "audio-alsa.h"
PUBLIC unsigned char _alsa_init (const char *name, audioCtxHandleT *ctx) {
snd_pcm_t *dev;
snd_pcm_hw_params_t *params;
int num;
if (snd_pcm_open (&dev, name, SND_PCM_STREAM_PLAYBACK, 0) < 0)
return 0;
snd_pcm_hw_params_malloc (¶ms);
snd_pcm_hw_params_any (dev, params);
snd_pcm_hw_params_set_access (dev, params, SND_PCM_ACCESS_RW_INTERLEAVED);
snd_pcm_hw_params_set_format (dev, params, SND_PCM_FORMAT_S16_LE);
snd_pcm_hw_params_set_rate_near (dev, params, &ctx->rate, 0);
snd_pcm_hw_params_set_channels (dev, params, ctx->channels);
if (snd_pcm_hw_params (dev, params) < 0) {
snd_pcm_hw_params_free (params);
return 0;
}
snd_pcm_prepare (dev);
/* allocate the global array if it hasn't been done */
if (!dev_ctx) {
dev_ctx = (dev_ctx_T**) malloc (sizeof(dev_ctx_T));
dev_ctx[0] = (dev_ctx_T*) malloc (sizeof(dev_ctx_T));
dev_ctx[0]->name = NULL;
dev_ctx[0]->dev = NULL;
}
/* is a card with similar name already opened ? */
for (num = 0; num < (sizeof(dev_ctx)/sizeof(dev_ctx_T)); num++) {
if (dev_ctx[num]->name &&
!strcmp (dev_ctx[num]->name, name))
return 0;
}
num++;
/* it's not... let us add it to the global array */
dev_ctx[num] = (dev_ctx_T*) malloc (sizeof(dev_ctx_T));
dev_ctx[num]->name = strdup (name);
dev_ctx[num]->dev = dev;
dev_ctx[num]->params = params;
return 1;
}
PUBLIC void _alsa_free (const char *name) {
int num;
for (num = 0; num < (sizeof(dev_ctx)/sizeof(dev_ctx_T)); num++) {
if (dev_ctx[num]->name &&
!strcmp (dev_ctx[num]->name, name)) {
snd_pcm_close (dev_ctx[num]->dev);
snd_pcm_hw_params_free (dev_ctx[num]->params);
free (dev_ctx[num]->name);
dev_ctx[num]->name = NULL;
dev_ctx[num]->dev = NULL;
free(dev_ctx[num]);
return;
}
}
}
PUBLIC void _alsa_play (unsigned int num, void *buf, int len) {
if (!dev_ctx || !dev_ctx[num])
return;
int16_t *cbuf = (int16_t *)buf;
int frames = len / 2;
int res;
if ((res = snd_pcm_writei (dev_ctx[num]->dev, cbuf, frames)) != frames) {
snd_pcm_recover (dev_ctx[num]->dev, res, 0);
snd_pcm_prepare (dev_ctx[num]->dev);
}
/* snd_pcm_drain (dev_ctx[num]->dev); */
}
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