Add track info support for BT audio sink (#2190)

Author: earlephilhower

libraries/BluetoothAudio/examples/A2DPSink/A2DPSink.ino

@@ -43,6 +43,8 @@ void setup() {
   a2dp.begin();
 }
 
+char *nowPlaying = nullptr;
+
 void loop() {
   if (BOOTSEL) {
     if (status == A2DPSink::PAUSED) {
@@ -54,4 +56,9 @@ void loop() {
     }
     while (BOOTSEL);
   }
+  if (!nowPlaying || strcmp(nowPlaying, a2dp.trackTitle())) {
+    free(nowPlaying);
+    nowPlaying = strdup(a2dp.trackTitle());
+    Serial.printf("NOW PLAYING: %s\n", nowPlaying);
+  }
 }

libraries/BluetoothAudio/src/A2DPSink.cpp

@@ -559,6 +559,14 @@ void A2DPSink::avrcp_controller_packet_handler(uint8_t packet_type, uint16_t cha
         break;
 
     case AVRCP_SUBEVENT_NOTIFICATION_TRACK_CHANGED:
+        _title[0] = 0;
+        _artist[0] = 0;
+        _album[0] = 0;
+        _genre[0] = 0;
+        avrcp_controller_get_now_playing_info(avrcp_connection->avrcp_cid);
+        if (_trackChangedCB) {
+            _trackChangedCB(_trackChangedData);
+        }
         DEBUGV("AVRCP Controller: Track changed\n");
         break;
 
@@ -585,27 +593,35 @@ void A2DPSink::avrcp_controller_packet_handler(uint8_t packet_type, uint16_t cha
     case AVRCP_SUBEVENT_NOW_PLAYING_TITLE_INFO:
         if (avrcp_subevent_now_playing_title_info_get_value_len(packet) > 0) {
             memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_title_info_get_value(packet), avrcp_subevent_now_playing_title_info_get_value_len(packet));
+            strncpy(_title, (char *)avrcp_subevent_value, sizeof(_title));
+            _title[sizeof(_title) - 1] = 0;
             DEBUGV("AVRCP Controller: Title %s\n", avrcp_subevent_value);
         }
         break;
 
     case AVRCP_SUBEVENT_NOW_PLAYING_ARTIST_INFO:
         if (avrcp_subevent_now_playing_artist_info_get_value_len(packet) > 0) {
             memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_artist_info_get_value(packet), avrcp_subevent_now_playing_artist_info_get_value_len(packet));
+            strncpy(_artist, (char *)avrcp_subevent_value, sizeof(_artist));
+            _artist[sizeof(_artist) - 1] = 0;
             DEBUGV("AVRCP Controller: Artist %s\n", avrcp_subevent_value);
         }
         break;
 
     case AVRCP_SUBEVENT_NOW_PLAYING_ALBUM_INFO:
         if (avrcp_subevent_now_playing_album_info_get_value_len(packet) > 0) {
             memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_album_info_get_value(packet), avrcp_subevent_now_playing_album_info_get_value_len(packet));
+            strncpy(_album, (char *)avrcp_subevent_value, sizeof(_album));
+            _album[sizeof(_album) - 1] = 0;
             DEBUGV("AVRCP Controller: Album %s\n", avrcp_subevent_value);
         }
         break;
 
     case AVRCP_SUBEVENT_NOW_PLAYING_GENRE_INFO:
         if (avrcp_subevent_now_playing_genre_info_get_value_len(packet) > 0) {
             memcpy(avrcp_subevent_value, avrcp_subevent_now_playing_genre_info_get_value(packet), avrcp_subevent_now_playing_genre_info_get_value_len(packet));
+            strncpy(_genre, (char *)avrcp_subevent_value, sizeof(_genre));
+            _genre[sizeof(_genre) - 1] = 0;
             DEBUGV("AVRCP Controller: Genre %s\n", avrcp_subevent_value);
         }
         break;

libraries/BluetoothAudio/src/A2DPSink.h

@@ -33,6 +33,10 @@
 class A2DPSink : public Stream {
 public:
     A2DPSink() {
+        _title[0] = 0;
+        _artist[0] = 0;
+        _album[0] = 0;
+        _genre[0] = 0;
     }
     virtual int available() override {
         return 0; // Unreadable, this is output only
@@ -96,6 +100,11 @@ class A2DPSink : public Stream {
         _connectData = cbData;
     }
 
+    void onTrackChanged(void (*cb)(void *), void *cbData = nullptr) {
+        _trackChangedCB = cb;
+        _trackChangedData = cbData;
+    }
+
     typedef enum { STOPPED, PLAYING, PAUSED } PlaybackStatus;
     void onPlaybackStatus(void (*cb)(void *, PlaybackStatus), void *cbData = nullptr) {
         _playbackStatusCB = cb;
@@ -190,6 +199,22 @@ class A2DPSink : public Stream {
         }
     }
 
+    const char *trackTitle() {
+        return _title;
+    }
+
+    const char *trackArtist() {
+        return _artist;
+    }
+
+    const char *trackAlbum() {
+        return _album;
+    }
+
+    const char *trackGenre() {
+        return _genre;
+    }
+
 private:
     void handle_pcm_data(int16_t * data, int num_audio_frames, int num_channels, int sample_rate, void * context);
 
@@ -224,6 +249,9 @@ class A2DPSink : public Stream {
     void *_connectData;
     void (*_playbackStatusCB)(void *, PlaybackStatus) = nullptr;
     void *_playbackStatusData;
+    void (*_trackChangedCB)(void *) = nullptr;
+    void *_trackChangedData;
+
     char *_name = nullptr;
     uint8_t _sourceAddress[6];
 
@@ -301,4 +329,9 @@ class A2DPSink : public Stream {
     a2dp_sink_avrcp_connection_t a2dp_sink_avrcp_connection;
 
     int16_t output_buffer[(128 + 16) * NUM_CHANNELS]; // 16 * 8 * 2
+
+    char _title[64];
+    char _artist[64];
+    char _album[64];
+    char _genre[32];
 };