Changeset 5616 for pjproject/trunk/pjmedia/src/pjmedia-audiodev/alsa_dev.c

Timestamp:

Jul 4, 2017 10:32:39 AM (7 years ago)

Author:

riza

Message:

Fix #1991: Support ALSA audio device volume setting.

File:

• pjproject/trunk/pjmedia/src/pjmedia-audiodev/alsa_dev.c (modified) (5 diffs)

pjproject/trunk/pjmedia/src/pjmedia-audiodev/alsa_dev.c

@@ -45 +45 @@
 #define MAX_SOUND_DEVICES_PER_CARD      5
 #define MAX_DEVICES                     32
+#define MAX_MIX_NAME_LEN                64 
 
 /* Set to 1 to enable tracing */
@@ -98 +99 @@
     unsigned                     dev_cnt;
     pjmedia_aud_dev_info         devs[MAX_DEVICES];
+    char                         pb_mixer_name[MAX_MIX_NAME_LEN];
 };
 
@@ -271 +273 @@
 }
 
+static void get_mixer_name(struct alsa_factory *af)
+{
+    snd_mixer_t *handle;
+    snd_mixer_elem_t *elem;
+
+    if (snd_mixer_open(&handle, 0) < 0)
+        return;
+
+    if (snd_mixer_attach(handle, "default") < 0) {
+        snd_mixer_close(handle);
+        return;
+    }
+
+    if (snd_mixer_selem_register(handle, NULL, NULL) < 0) {
+        snd_mixer_close(handle);
+        return;
+    }
+
+    if (snd_mixer_load(handle) < 0) {
+        snd_mixer_close(handle);
+        return;
+    }
+
+    for (elem = snd_mixer_first_elem(handle); elem;
+         elem = snd_mixer_elem_next(elem))
+    {
+        if (snd_mixer_selem_is_active(elem) &&
+            snd_mixer_selem_has_playback_volume(elem))
+        {
+            pj_ansi_strncpy(af->pb_mixer_name, snd_mixer_selem_get_name(elem),
+                            sizeof(af->pb_mixer_name));
+            TRACE_((THIS_FILE, "Playback mixer name: %s", af->pb_mixer_name));
+            break;
+        }
+    }
+    snd_mixer_close(handle);
+}
+
 
 /* Create ALSA audio driver. */
@@ -356 +396 @@
         n++;
     }
+
+    /* Get the mixer name */
+    get_mixer_name(af);
 
     /* Install error handler after enumeration, otherwise we'll get many
@@ -893 +936 @@
                                        const void *value)
 {
-    PJ_UNUSED_ARG(strm);
-    PJ_UNUSED_ARG(cap);
-    PJ_UNUSED_ARG(value);
+    struct alsa_factory *af = ((struct alsa_stream*)strm)->af;
+
+    if (cap==PJMEDIA_AUD_DEV_CAP_OUTPUT_VOLUME_SETTING && af->pb_mixer_name) {
+        int result;
+        pj_ssize_t min, max;
+        snd_mixer_t *handle;
+        snd_mixer_selem_id_t *sid;
+        snd_mixer_elem_t* elem;
+        unsigned vol = *(unsigned*)value;
+
+        if (snd_mixer_open(&handle, 0) < 0)
+            return PJMEDIA_EAUD_SYSERR;
+
+        if (snd_mixer_attach(handle, "default") < 0)
+            return PJMEDIA_EAUD_SYSERR;
+
+        if (snd_mixer_selem_register(handle, NULL, NULL) < 0)
+            return PJMEDIA_EAUD_SYSERR;
+
+        if (snd_mixer_load(handle) < 0)
+            return PJMEDIA_EAUD_SYSERR;
+
+        snd_mixer_selem_id_alloca(&sid);
+        snd_mixer_selem_id_set_index(sid, 0);
+        snd_mixer_selem_id_set_name(sid, af->pb_mixer_name);
+        elem = snd_mixer_find_selem(handle, sid);
+        if (!elem)
+            return PJMEDIA_EAUD_SYSERR;
+
+        snd_mixer_selem_get_playback_volume_range(elem, &min, &max);
+        if (snd_mixer_selem_set_playback_volume_all(elem, vol * max / 100) < 0)
+            return PJMEDIA_EAUD_SYSERR;
+
+        snd_mixer_close(handle);
+        return PJ_SUCCESS;
+    }
 
     return PJMEDIA_EAUD_INVCAP;