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/*
* Copyright (C) 2015 "IoT.bzh"
* Author "Manuel Bachmann"
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#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;
snd_mixer_t *mixer;
snd_mixer_selem_id_t *mixer_sid;
snd_mixer_elem_t *mixer_elm;
unsigned int rate = 22050;
long vol, vol_min, vol_max;
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, &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);
snd_mixer_open (&mixer, 0);
if (snd_mixer_attach (mixer, name) < 0) {
snd_pcm_hw_params_free (params);
return 0;
}
snd_mixer_selem_register (mixer, NULL, NULL);
snd_mixer_load (mixer);
snd_mixer_selem_id_alloca (&mixer_sid);
snd_mixer_selem_id_set_index (mixer_sid, 0);
snd_mixer_selem_id_set_name (mixer_sid, "Master");
mixer_elm = snd_mixer_find_selem (mixer, mixer_sid);
snd_mixer_selem_get_playback_volume_range (mixer_elm, &vol_min, &vol_max);
snd_mixer_selem_get_playback_volume (mixer_elm, SND_MIXER_SCHN_FRONT_LEFT, &vol);
/* 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 = (dev_ctx_T**) realloc (dev_ctx, (num+1)*sizeof(dev_ctx_T));
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;
dev_ctx[num]->mixer_elm = mixer_elm;
dev_ctx[num]->vol_max = vol_max;
dev_ctx[num]->vol = vol;
/* make the client context aware of current card state */
ctx->volume = _alsa_get_volume (num);
ctx->mute = _alsa_get_mute (num);
ctx->idx = num;
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); */
}
PUBLIC unsigned int _alsa_get_volume (unsigned int num) {
if (!dev_ctx || !dev_ctx[num])
return;
snd_mixer_selem_get_playback_volume (dev_ctx[num]->mixer_elm, SND_MIXER_SCHN_FRONT_LEFT, &dev_ctx[num]->vol);
return (unsigned int)(dev_ctx[num]->vol*100)/dev_ctx[num]->vol_max;
}
PUBLIC unsigned int _alsa_set_volume (unsigned int num, unsigned int vol) {
if (!dev_ctx || !dev_ctx[num] || vol > 100)
return;
snd_mixer_selem_set_playback_volume_all (dev_ctx[num]->mixer_elm, (vol*dev_ctx[num]->vol_max)/100);
}
PUBLIC unsigned char _alsa_get_mute (unsigned int num) {
int mute = 0;
if (!dev_ctx || !dev_ctx[num])
return;
if (snd_mixer_selem_has_playback_switch (dev_ctx[num]->mixer_elm)) {
snd_mixer_selem_get_playback_switch (dev_ctx[num]->mixer_elm, SND_MIXER_SCHN_FRONT_LEFT, &mute);
snd_mixer_selem_get_playback_switch (dev_ctx[num]->mixer_elm, SND_MIXER_SCHN_FRONT_RIGHT, &mute);
}
return (unsigned char)mute;
}
PUBLIC void _alsa_set_mute (unsigned int num, unsigned char mute) {
if (!dev_ctx || !dev_ctx[num] || 1 < mute < 0)
return;
if (snd_mixer_selem_has_playback_switch (dev_ctx[num]->mixer_elm))
snd_mixer_selem_set_playback_switch_all (dev_ctx[num]->mixer_elm, mute);
}
PUBLIC void _alsa_set_rate (unsigned int num, unsigned int rate) {
if (!dev_ctx || !dev_ctx[num])
return;
snd_pcm_hw_params_set_rate_near (dev_ctx[num]->dev, dev_ctx[num]->params, &rate, 0);
}
PUBLIC void _alsa_set_channels (unsigned int num, unsigned int channels) {
if (!dev_ctx || !dev_ctx[num])
return;
snd_pcm_hw_params_set_channels (dev_ctx[num]->dev, dev_ctx[num]->params, channels);
}
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