2 * Copyright (C) 2015 "IoT.bzh"
3 * Author "Manuel Bachmann"
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 #include "audio-api.h"
20 #include "audio-alsa.h"
22 PUBLIC unsigned char _alsa_init (const char *name, audioCtxHandleT *ctx) {
25 snd_pcm_hw_params_t *params;
27 snd_mixer_selem_id_t *mixer_sid;
28 snd_mixer_elem_t *mixer_elm;
29 unsigned int rate = 22050;
30 long vol, vol_min, vol_max;
33 if (snd_pcm_open (&dev, name, SND_PCM_STREAM_PLAYBACK, 0) < 0)
36 snd_pcm_hw_params_malloc (¶ms);
37 snd_pcm_hw_params_any (dev, params);
38 snd_pcm_hw_params_set_access (dev, params, SND_PCM_ACCESS_RW_INTERLEAVED);
39 snd_pcm_hw_params_set_format (dev, params, SND_PCM_FORMAT_S16_LE);
40 snd_pcm_hw_params_set_rate_near (dev, params, &rate, 0);
41 snd_pcm_hw_params_set_channels (dev, params, ctx->channels);
42 if (snd_pcm_hw_params (dev, params) < 0) {
43 snd_pcm_hw_params_free (params);
46 snd_pcm_prepare (dev);
48 snd_mixer_open (&mixer, 0);
49 if (snd_mixer_attach (mixer, name) < 0) {
50 snd_pcm_hw_params_free (params);
53 snd_mixer_selem_register (mixer, NULL, NULL);
54 snd_mixer_load (mixer);
56 snd_mixer_selem_id_alloca (&mixer_sid);
57 snd_mixer_selem_id_set_index (mixer_sid, 0);
58 snd_mixer_selem_id_set_name (mixer_sid, "Master");
60 mixer_elm = snd_mixer_find_selem (mixer, mixer_sid);
61 snd_mixer_selem_get_playback_volume_range (mixer_elm, &vol_min, &vol_max);
62 snd_mixer_selem_get_playback_volume (mixer_elm, SND_MIXER_SCHN_FRONT_LEFT, &vol);
64 /* allocate the global array if it hasn't been done */
66 dev_ctx = (dev_ctx_T**) malloc (sizeof(dev_ctx_T));
67 dev_ctx[0] = (dev_ctx_T*) malloc (sizeof(dev_ctx_T));
68 dev_ctx[0]->name = NULL;
69 dev_ctx[0]->dev = NULL;
72 /* is a card with similar name already opened ? */
73 for (num = 0; num < (sizeof(dev_ctx)/sizeof(dev_ctx_T)); num++) {
74 if (dev_ctx[num]->name &&
75 !strcmp (dev_ctx[num]->name, name))
80 /* it's not... let us add it to the global array */
81 dev_ctx = (dev_ctx_T**) realloc (dev_ctx, (num+1)*sizeof(dev_ctx_T));
82 dev_ctx[num] = (dev_ctx_T*) malloc (sizeof(dev_ctx_T));
83 dev_ctx[num]->name = strdup (name);
84 dev_ctx[num]->dev = dev;
85 dev_ctx[num]->params = params;
86 dev_ctx[num]->mixer_elm = mixer_elm;
87 dev_ctx[num]->vol_max = vol_max;
88 dev_ctx[num]->vol = vol;
90 /* make the client context aware of current card state */
91 ctx->volume = _alsa_get_volume (num);
92 ctx->mute = _alsa_get_mute (num);
98 PUBLIC void _alsa_free (const char *name) {
102 for (num = 0; num < (sizeof(dev_ctx)/sizeof(dev_ctx_T)); num++) {
103 if (dev_ctx[num]->name &&
104 !strcmp (dev_ctx[num]->name, name)) {
105 snd_pcm_close (dev_ctx[num]->dev);
106 snd_pcm_hw_params_free (dev_ctx[num]->params);
107 free (dev_ctx[num]->name);
108 dev_ctx[num]->name = NULL;
109 dev_ctx[num]->dev = NULL;
116 PUBLIC void _alsa_play (unsigned int num, void *buf, int len) {
118 if (!dev_ctx || !dev_ctx[num])
121 int16_t *cbuf = (int16_t *)buf;
122 int frames = len / 2;
125 if ((res = snd_pcm_writei (dev_ctx[num]->dev, cbuf, frames)) != frames) {
126 snd_pcm_recover (dev_ctx[num]->dev, res, 0);
127 snd_pcm_prepare (dev_ctx[num]->dev);
129 /* snd_pcm_drain (dev_ctx[num]->dev); */
132 PUBLIC unsigned int _alsa_get_volume (unsigned int num) {
134 if (!dev_ctx || !dev_ctx[num])
137 snd_mixer_selem_get_playback_volume (dev_ctx[num]->mixer_elm, SND_MIXER_SCHN_FRONT_LEFT, &dev_ctx[num]->vol);
139 return (unsigned int)(dev_ctx[num]->vol*100)/dev_ctx[num]->vol_max;
142 PUBLIC unsigned int _alsa_set_volume (unsigned int num, unsigned int vol) {
144 if (!dev_ctx || !dev_ctx[num] || vol > 100)
147 snd_mixer_selem_set_playback_volume_all (dev_ctx[num]->mixer_elm, (vol*dev_ctx[num]->vol_max)/100);
150 PUBLIC unsigned char _alsa_get_mute (unsigned int num) {
154 if (!dev_ctx || !dev_ctx[num])
157 if (snd_mixer_selem_has_playback_switch (dev_ctx[num]->mixer_elm)) {
158 snd_mixer_selem_get_playback_switch (dev_ctx[num]->mixer_elm, SND_MIXER_SCHN_FRONT_LEFT, &mute);
159 snd_mixer_selem_get_playback_switch (dev_ctx[num]->mixer_elm, SND_MIXER_SCHN_FRONT_RIGHT, &mute);
163 return (unsigned char)!mute;
166 PUBLIC void _alsa_set_mute (unsigned int num, unsigned char mute) {
168 if (!dev_ctx || !dev_ctx[num] || 1 < mute < 0)
171 if (snd_mixer_selem_has_playback_switch (dev_ctx[num]->mixer_elm))
172 snd_mixer_selem_set_playback_switch_all (dev_ctx[num]->mixer_elm, !mute);
175 PUBLIC void _alsa_set_rate (unsigned int num, unsigned int rate) {
177 if (!dev_ctx || !dev_ctx[num])
180 snd_pcm_hw_params_set_rate_near (dev_ctx[num]->dev, dev_ctx[num]->params, &rate, 0);
183 PUBLIC void _alsa_set_channels (unsigned int num, unsigned int channels) {
185 if (!dev_ctx || !dev_ctx[num])
188 snd_pcm_hw_params_set_channels (dev_ctx[num]->dev, dev_ctx[num]->params, channels);