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-rw-r--r--bindings/audio/audio-alsa.c311
1 files changed, 311 insertions, 0 deletions
diff --git a/bindings/audio/audio-alsa.c b/bindings/audio/audio-alsa.c
new file mode 100644
index 00000000..45ff2edb
--- /dev/null
+++ b/bindings/audio/audio-alsa.c
@@ -0,0 +1,311 @@
+/*
+ * Copyright (C) 2015, 2016 "IoT.bzh"
+ * Author "Manuel Bachmann"
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "audio-api.h"
+#include "audio-alsa.h"
+
+snd_mixer_selem_channel_id_t SCHANNELS[8] = {
+ SND_MIXER_SCHN_FRONT_LEFT,
+ SND_MIXER_SCHN_FRONT_RIGHT,
+ SND_MIXER_SCHN_FRONT_CENTER,
+ SND_MIXER_SCHN_REAR_LEFT,
+ SND_MIXER_SCHN_REAR_RIGHT,
+ SND_MIXER_SCHN_REAR_CENTER,
+ SND_MIXER_SCHN_SIDE_LEFT,
+ SND_MIXER_SCHN_SIDE_RIGHT
+};
+
+static struct dev_ctx_alsa **dev_ctx_a = NULL;
+
+
+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;
+ snd_mixer_elem_t *mixer_elm_m;
+ unsigned int rate = 22050;
+ long vol, vol_min, vol_max;
+ int num, i;
+
+ if (snd_pcm_open (&dev, name, SND_PCM_STREAM_PLAYBACK, 0) < 0) {
+ fprintf (stderr, "ALSA backend could not open card '%s'\n", name);
+ return 0;
+ }
+
+ snd_pcm_hw_params_malloc (&params);
+ 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);
+ fprintf (stderr, "ALSA backend could set channels on card '%s'\n", name);
+ return 0;
+ }
+ snd_pcm_prepare (dev);
+
+ snd_mixer_open (&mixer, 0);
+ if (snd_mixer_attach (mixer, name) < 0) {
+ snd_pcm_hw_params_free (params);
+ fprintf (stderr, "ALSA backend could not open mixer for card '%s'\n", name);
+ 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);
+ mixer_elm_m = NULL;
+
+ if (!mixer_elm) {
+ /* no "Master" mixer ; we are probably on a board... search ! */
+ for (mixer_elm = snd_mixer_first_elem (mixer); mixer_elm != NULL;
+ mixer_elm = snd_mixer_elem_next (mixer_elm)) {
+ if (snd_mixer_elem_info (mixer_elm) < 0)
+ continue;
+ snd_mixer_selem_get_id (mixer_elm, mixer_sid);
+ if (strstr (snd_mixer_selem_id_get_name (mixer_sid), "DVC Out")) {
+
+ /* this is Porter... let us found the specific mute switch */
+ snd_mixer_selem_id_set_index (mixer_sid, 0);
+ snd_mixer_selem_id_set_name (mixer_sid, "DVC Out Mute");
+ mixer_elm_m = snd_mixer_find_selem (mixer, mixer_sid);
+
+ break;
+ }
+ }
+ }
+
+ 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 (!dev_ctx_a) {
+ dev_ctx_a = (dev_ctx_alsa_T**) malloc (sizeof(dev_ctx_alsa_T*));
+ dev_ctx_a[0] = (dev_ctx_alsa_T*) malloc (sizeof(dev_ctx_alsa_T));
+ dev_ctx_a[0]->name = NULL;
+ dev_ctx_a[0]->dev = NULL;
+ }
+
+ /* is a card with similar name already opened ? */
+ for (num = 0; num < (sizeof(dev_ctx_a)/sizeof(dev_ctx_alsa_T*)); num++) {
+ if (dev_ctx_a[num]->name &&
+ !strcmp (dev_ctx_a[num]->name, name)) {
+ fprintf (stderr, "Card '%s' already locked by other ALSA backend session\n", name);
+ return 0;
+ }
+ }
+ num--;
+
+ /* it's not... let us add it to the global array */
+ dev_ctx_a = (dev_ctx_alsa_T**) realloc (dev_ctx_a, (num+1)*sizeof(dev_ctx_alsa_T*));
+ if (!dev_ctx_a[num])
+ dev_ctx_a[num] = (dev_ctx_alsa_T*) malloc (sizeof(dev_ctx_alsa_T));
+ dev_ctx_a[num]->name = strdup (name);
+ dev_ctx_a[num]->dev = dev;
+ dev_ctx_a[num]->params = params;
+ dev_ctx_a[num]->mixer_elm = mixer_elm;
+ dev_ctx_a[num]->mixer_elm_m = mixer_elm_m;
+ dev_ctx_a[num]->vol_max = vol_max;
+ dev_ctx_a[num]->vol = vol;
+ dev_ctx_a[num]->thr_should_run = 0;
+ dev_ctx_a[num]->thr_finished = 0;
+
+ /* make the client context aware of current card state */
+ for (i = 0; i < 8; i++)
+ ctx->volume[i] = _alsa_get_volume (num, i);
+ ctx->mute = _alsa_get_mute (num);
+ ctx->idx = num;
+ ctx->name = strdup (name);
+
+ fprintf (stderr, "Successfully initialized ALSA backend.\n");
+
+ return 1;
+}
+
+void _alsa_free (const char *name) {
+
+ int num;
+
+ for (num = 0; num < (sizeof(dev_ctx_a)/sizeof(dev_ctx_alsa_T*)); num++) {
+ if (dev_ctx_a[num]->name &&
+ !strcmp (dev_ctx_a[num]->name, name)) {
+ snd_pcm_close (dev_ctx_a[num]->dev);
+ snd_pcm_hw_params_free (dev_ctx_a[num]->params);
+ free (dev_ctx_a[num]->name);
+ dev_ctx_a[num]->dev = NULL;
+ dev_ctx_a[num]->name = NULL;
+ free (dev_ctx_a[num]);
+ return;
+ }
+ }
+}
+
+void _alsa_play (int num) {
+
+ if (!dev_ctx_a || !dev_ctx_a[num] || dev_ctx_a[num]->thr_should_run ||
+ access (AUDIO_BUFFER, F_OK) == -1)
+ return;
+
+ dev_ctx_a[num]->thr_should_run = 1;
+ dev_ctx_a[num]->thr_finished = 0;
+ pthread_create (&dev_ctx_a[num]->thr, NULL, _alsa_play_thread_fn, (void*)dev_ctx_a[num]);
+}
+
+void _alsa_stop (int num) {
+
+ if (!dev_ctx_a || !dev_ctx_a[num] || !dev_ctx_a[num]->thr_should_run)
+ return;
+
+ /* stop the "while" loop in thread */
+ dev_ctx_a[num]->thr_should_run = 0;
+
+ while (!dev_ctx_a[num]->thr_finished)
+ usleep(100000);
+
+ pthread_join (dev_ctx_a[num]->thr, NULL);
+}
+
+unsigned int _alsa_get_volume (int num, unsigned int channel) {
+
+ if (!dev_ctx_a || !dev_ctx_a[num] || !dev_ctx_a[num]->mixer_elm)
+ return 0;
+
+ snd_mixer_selem_get_playback_volume (dev_ctx_a[num]->mixer_elm, SCHANNELS[channel], &dev_ctx_a[num]->vol);
+
+ return (unsigned int)(dev_ctx_a[num]->vol*100)/dev_ctx_a[num]->vol_max;
+}
+
+void _alsa_set_volume (int num, unsigned int channel, unsigned int vol) {
+
+ if (!dev_ctx_a || !dev_ctx_a[num] || !dev_ctx_a[num]->mixer_elm ||
+ vol > 100)
+ return;
+
+ snd_mixer_selem_set_playback_volume (dev_ctx_a[num]->mixer_elm, SCHANNELS[channel], (vol*dev_ctx_a[num]->vol_max)/100);
+}
+
+void _alsa_set_volume_all (int num, unsigned int vol) {
+
+ if (!dev_ctx_a || !dev_ctx_a[num] || !dev_ctx_a[num]->mixer_elm ||
+ vol > 100)
+
+ fflush (stdout); /* seems to force this logic to apply quickly */
+ snd_mixer_selem_set_playback_volume_all (dev_ctx_a[num]->mixer_elm, (vol*dev_ctx_a[num]->vol_max)/100);
+}
+
+unsigned char _alsa_get_mute (int num) {
+
+ int mute = 0;
+ snd_mixer_elem_t *elm_m;
+
+ if (!dev_ctx_a || !dev_ctx_a[num] || !dev_ctx_a[num]->mixer_elm)
+ return 0;
+
+ dev_ctx_a[num]->mixer_elm_m ? (elm_m = dev_ctx_a[num]->mixer_elm_m) :
+ (elm_m = dev_ctx_a[num]->mixer_elm);
+
+ if (snd_mixer_selem_has_playback_switch (elm_m)) {
+ snd_mixer_selem_get_playback_switch (elm_m, SND_MIXER_SCHN_FRONT_LEFT, &mute);
+ snd_mixer_selem_get_playback_switch (elm_m, SND_MIXER_SCHN_FRONT_RIGHT, &mute);
+ }
+
+ if (dev_ctx_a[num]->mixer_elm_m)
+ return (unsigned char)mute;
+ else
+ return (unsigned char)!mute;
+}
+
+void _alsa_set_mute (int num, unsigned char tomute) {
+
+ snd_mixer_elem_t *elm_m;
+ int mute;
+
+ if (!dev_ctx_a || !dev_ctx_a[num] || !dev_ctx_a[num]->mixer_elm || 1 < tomute)
+ return;
+
+ if (dev_ctx_a[num]->mixer_elm_m) {
+ elm_m = dev_ctx_a[num]->mixer_elm_m;
+ mute = (int)!tomute;
+ } else {
+ elm_m = dev_ctx_a[num]->mixer_elm;
+ mute = (int)tomute;
+ }
+
+ if (snd_mixer_selem_has_playback_switch (elm_m))
+ snd_mixer_selem_set_playback_switch_all (elm_m, !mute);
+}
+
+void _alsa_set_rate (int num, unsigned int rate) {
+
+ if (!dev_ctx_a || !dev_ctx_a[num])
+ return;
+
+ snd_pcm_hw_params_set_rate_near (dev_ctx_a[num]->dev, dev_ctx_a[num]->params, &rate, 0);
+}
+
+void _alsa_set_channels (int num, unsigned int channels) {
+
+ if (!dev_ctx_a || !dev_ctx_a[num])
+ return;
+
+ snd_pcm_hw_params_set_channels (dev_ctx_a[num]->dev, dev_ctx_a[num]->params, channels);
+}
+
+ /* ---- LOCAL THREADED FUNCTIONS ---- */
+
+void* _alsa_play_thread_fn (void *ctx) {
+
+ dev_ctx_alsa_T *dev_ctx_a = (dev_ctx_alsa_T *)ctx;
+ FILE *file = NULL;
+ char *buf = NULL;
+ long size;
+ int frames, res;
+
+ file = fopen (AUDIO_BUFFER, "rb");
+
+ while (dev_ctx_a->thr_should_run && file && (access (AUDIO_BUFFER, F_OK) != -1) ) {
+ fseek (file, 0, SEEK_END);
+ size = ftell (file);
+ buf = (char*) realloc (buf, size * sizeof(char));
+ frames = (size * sizeof(char)) / 4;
+
+ fseek (file, 0, SEEK_SET);
+ fread (buf, 1, size, file);
+ fflush (file);
+
+ if ((res = snd_pcm_writei (dev_ctx_a->dev, buf, frames)) != frames) {
+ snd_pcm_recover (dev_ctx_a->dev, res, 0);
+ snd_pcm_prepare (dev_ctx_a->dev);
+ }
+ /* snd_pcm_drain (dev_ctx->dev); */
+ }
+ if (buf) free(buf);
+ if (file) fclose(file);
+
+ dev_ctx_a->thr_finished = 1;
+ return 0;
+}