Added bluez sound playback support

This adds sound playback for incoming sound from
connected bluetooth devices.
In this version, the softmixer relies on a modified
bluez-alsa version (https://github.com/iotbzh/bluez-alsa),
that provides an ioplug PCM bluezalsa connection proxy.

The softmixer api has a new verb to dynamically set the
device to listen to:

afb-client-demo ws://localhost:1234/api?token=\uuid=123 smixer bluezalsa_dev '{"interface":"hci0", "device":"F6:32:15:2A:80:70", "profile":"a2dp"}'

In this way it is possible to switch from a bluezalsa audio source to
another without any further configuration.

For now, only interface hci0 is supported.

This commit also migrates the softmixer binding to API v3

Signed-off-by: Thierry Bultel <thierry.bultel@iot.bzh>

1 files changed, 15 insertions, 1 deletions

diff --git a/plugins/alsa/alsa-core-ctl.c b/plugins/alsa/alsa-core-ctl.c
index d128b6c..01e560f 100644
--- a/plugins/alsa/alsa-core-ctl.c
+++ b/plugins/alsa/alsa-core-ctl.c
@@ -25,6 +25,8 @@ for the specific language governing permissions and
 #define _GNU_SOURCE  // needed for vasprintf
 
 #include "alsa-softmixer.h"
+#include "alsa-bluez.h"
+
 #include <pthread.h>
 #include <sys/syscall.h>
 
@@ -279,12 +281,22 @@ OnErrorExit:
 
 // Clone of AlsaLib snd_card_load2 static function
 
-PUBLIC snd_ctl_card_info_t *AlsaCtlGetInfo(SoftMixerT *mixer, const char *cardid) {
+PUBLIC snd_ctl_card_info_t *AlsaCtlGetCardInfo(SoftMixerT *mixer, const char *cardid) {
     int error;
     snd_ctl_t *ctl;
 
     AFB_ApiNotice(mixer->api, "Looking for card '%s'", cardid);
 
+    /* "bluealsa" is the name of the control external plugin
+     * (https://www.alsa-project.org/alsa-doc/alsa-lib/ctl_external_plugins.html)
+     */
+    if (strstr(cardid, "bluealsa")) {
+    	cardid="bluealsa";
+    	alsa_bluez_init();
+    }
+
+    AFB_ApiNotice(mixer->api, "Opening card control '%s'", cardid);
+
     if ((error = snd_ctl_open(&ctl, cardid, SND_CTL_READONLY)) < 0) {
         cardid = "Not Defined";
         goto OnErrorExit;
@@ -627,6 +639,8 @@ OnErrorExit:
 PUBLIC int AlsaCtlRegister(SoftMixerT *mixer, AlsaSndCtlT *sndcard, AlsaPcmCtlT *pcmdev, RegistryNumidT type, int numid) {
     int index;
 
+    AFB_ApiInfo(mixer->api,"%s: %d!\n", __func__, numid);
+
     for (index = 0; index < sndcard->rcount; index++) {
         if (!sndcard->registry[index]) break;
     }