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, 67 insertions, 0 deletions

diff --git a/plugins/alsa/alsa-bluez.c b/plugins/alsa/alsa-bluez.c
new file mode 100644
index 0000000..bd6bc99
--- /dev/null
+++ b/plugins/alsa/alsa-bluez.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright(C) 2018 "IoT.bzh"
+ * Author Thierry Bultel <thierry.bultel@iot.bzh>
+ *
+ * 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 "alsa-bluez.h"
+
+#include <stdbool.h>
+#include <dlfcn.h>
+
+#define ALSA_BLUEZ_PROXY_LIB "/usr/lib/alsa-lib/libasound_module_pcm_bluealsa_proxy.so"
+#define ALSA_BLUEZ_PROXY_SETDEVICE "bluealsa_proxy_set_remote_device"
+
+typedef	int (*bluealsa_set_remote_device_ptr) (const char * interface, const char * device, const char * profile);
+
+static bluealsa_set_remote_device_ptr bluealsa_proxy_set_remote_device = NULL;
+
+void alsa_bluez_init() {
+	static bool initialized = false;
+	if (initialized)
+		goto failed;
+
+	char errbuf[256];
+	void * dl = snd_dlopen(ALSA_BLUEZ_PROXY_LIB, RTLD_NOW, errbuf, 256);
+	if (!dl) {
+		printf("Failed to open bluealsa proxy plugin\n");
+		goto failed;
+	}
+
+	void * func = snd_dlsym(dl, ALSA_BLUEZ_PROXY_SETDEVICE, SND_DLSYM_VERSION(SND_PCM_DLSYM_VERSION));
+	if (!func) {
+		printf("Unable to find %s symbol\n", ALSA_BLUEZ_PROXY_SETDEVICE);
+		goto failed;
+	}
+
+	bluealsa_proxy_set_remote_device = func;
+	initialized = true;
+
+failed:
+	return;
+}
+
+int alsa_bluez_set_device(const char * interface, const char * device, const char * profile) {
+	if (!bluealsa_proxy_set_remote_device)
+		return -1;
+
+	return bluealsa_proxy_set_remote_device(interface,device,profile);
+}
+
+