1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
/*
* 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);
if (mixer_elm) {
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 (!adev_ctx) {
adev_ctx = (adev_ctx_T**) malloc (sizeof(adev_ctx_T));
adev_ctx[0] = (adev_ctx_T*) malloc (sizeof(adev_ctx_T));
adev_ctx[0]->name = NULL;
adev_ctx[0]->dev = NULL;
}
/* is a card with similar name already opened ? */
for (num = 0; num < (sizeof(adev_ctx)/sizeof(adev_ctx_T)); num++) {
if (adev_ctx[num]->name &&
!strcmp (adev_ctx[num]->name, name))
return 0;
}
num++;
/* it's not... let us add it to the global array */
adev_ctx = (adev_ctx_T**) realloc (adev_ctx, (num+1)*sizeof(adev_ctx_T));
adev_ctx[num] = (adev_ctx_T*) malloc (sizeof(adev_ctx_T));
adev_ctx[num]->name = strdup (name);
adev_ctx[num]->dev = dev;
adev_ctx[num]->params = params;
adev_ctx[num]->mixer_elm = mixer_elm;
adev_ctx[num]->vol_max = vol_max;
adev_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(adev_ctx)/sizeof(adev_ctx_T)); num++) {
if (adev_ctx[num]->name &&
!strcmp (adev_ctx[num]->name, name)) {
snd_pcm_close (adev_ctx[num]->dev);
snd_pcm_hw_params_free (adev_ctx[num]->params);
free (adev_ctx[num]->name);
adev_ctx[num]->name = NULL;
adev_ctx[num]->dev = NULL;
free(adev_ctx[num]);
return;
}
}
}
PUBLIC void _alsa_play (unsigned int num, void *buf, int len) {
if (!adev_ctx || !adev_ctx[num]) {
return;
}
int16_t *cbuf = (int16_t *)buf;
int frames = len / 2;
int res;
if ((res = snd_pcm_writei (adev_ctx[num]->dev, cbuf, frames)) != frames) {
snd_pcm_recover (adev_ctx[num]->dev, res, 0);
snd_pcm_prepare (adev_ctx[num]->dev);
}
/* snd_pcm_drain (adev_ctx[num]->dev); */
}
PUBLIC unsigned int _alsa_get_volume (unsigned int num) {
if (!adev_ctx || !adev_ctx[num] || !adev_ctx[num]->mixer_elm)
return;
snd_mixer_selem_get_playback_volume (adev_ctx[num]->mixer_elm, SND_MIXER_SCHN_FRONT_LEFT, &adev_ctx[num]->vol);
return (unsigned int)(adev_ctx[num]->vol*100)/adev_ctx[num]->vol_max;
}
PUBLIC unsigned int _alsa_set_volume (unsigned int num, unsigned int vol) {
if (!adev_ctx || !adev_ctx[num] || !adev_ctx[num]->mixer_elm || vol > 100)
return;
snd_mixer_selem_set_playback_volume_all (adev_ctx[num]->mixer_elm, (vol*adev_ctx[num]->vol_max)/100);
}
PUBLIC unsigned char _alsa_get_mute (unsigned int num) {
int mute = 0;
if (!adev_ctx || !adev_ctx[num] || !adev_ctx[num]->mixer_elm)
return;
if (snd_mixer_selem_has_playback_switch (adev_ctx[num]->mixer_elm)) {
snd_mixer_selem_get_playback_switch (adev_ctx[num]->mixer_elm, SND_MIXER_SCHN_FRONT_LEFT, &mute);
snd_mixer_selem_get_playback_switch (adev_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 (!adev_ctx || !adev_ctx[num] || !adev_ctx[num]->mixer_elm || 1 < mute < 0)
return;
if (snd_mixer_selem_has_playback_switch (adev_ctx[num]->mixer_elm))
snd_mixer_selem_set_playback_switch_all (adev_ctx[num]->mixer_elm, !mute);
}
PUBLIC void _alsa_set_rate (unsigned int num, unsigned int rate) {
if (!adev_ctx || !adev_ctx[num])
return;
snd_pcm_hw_params_set_rate_near (adev_ctx[num]->dev, adev_ctx[num]->params, &rate, 0);
}
PUBLIC void _alsa_set_channels (unsigned int num, unsigned int channels) {
if (!adev_ctx || !adev_ctx[num])
return;
snd_pcm_hw_params_set_channels (adev_ctx[num]->dev, adev_ctx[num]->params, channels);
}
|
