Bluetooth information

[Sixonlon]

Hi man,

Thks for your wonderfull job !

I wonder if there would be a way to retrive information from the music that is streamed to the ESP32? I think of title, album, etc

[tierneytim]

Thanks man,

I think so using the AVRC profile but it may be complicated for two reasons. 1) the example code to use the profile is hard to understand and 2) it requires that the device sending the audio also uses this profile which there is no guarantee of.

What is the application you are thinking of?

[Sixonlon]

I'm trying to convert an old Phillips car radio to a modern system. I wire up a DAB+ shield to my ESP32 and add the blutooth function using your work but i'd like to display music info on the LCD. I can do it with the DAB shield for the radio part but I struggle with bluetooth one

[tierneytim]

Sounds Like a cool idea. This will probably take some time to get working but I think it will be a very useful addition. Will close issue when implemented.

[tierneytim]

OK, metadata queries are now possible with the updateMeta method. Examples are provided for printing, title, artist, album and genre to the serial port. Let me know if this works for you.

[Sixonlon]

Thks for the responsivness. The qeries work perfectly. Thks for your work and merry christmass

[haldi4803]

If one would like to expand the metadata with other info... The void updateMeta(); asks in the btaudio.cpp

void btAudio::updateMeta() {
  uint8_t attr_mask = ESP_AVRC_MD_ATTR_TITLE | ESP_AVRC_MD_ATTR_ARTIST | ESP_AVRC_MD_ATTR_ALBUM | ESP_AVRC_MD_ATTR_GENRE;
  esp_avrc_ct_send_metadata_cmd(1, attr_mask);
}

but the whole definition happens in the next function.

void btAudio::avrc_callback(esp_avrc_ct_cb_event_t event, esp_avrc_ct_cb_param_t *param) {
  esp_avrc_ct_cb_param_t *rc = (esp_avrc_ct_cb_param_t *)(param);
  char *attr_text;
  String mystr;

  switch (event) {
    case ESP_AVRC_CT_METADATA_RSP_EVT: {
      attr_text = (char *) malloc (rc->meta_rsp.attr_length + 1);
      memcpy(attr_text, rc->meta_rsp.attr_text, rc->meta_rsp.attr_length);
      attr_text[rc->meta_rsp.attr_length] = 0;
      mystr = String(attr_text);

      switch (rc->meta_rsp.attr_id) {
        case ESP_AVRC_MD_ATTR_TITLE:
          //Serial.print("Title: ");
          //Serial.println(mystr);
          title= mystr;
          break;
        case ESP_AVRC_MD_ATTR_ARTIST:
          //Serial.print("Artist: ");
          //Serial.println(mystr);
          artist= mystr;
          break;
        case ESP_AVRC_MD_ATTR_ALBUM:
          //Serial.print("Album: ");
          //Serial.println(mystr);
          album= mystr;
          break;
        case ESP_AVRC_MD_ATTR_GENRE:
          //Serial.print("Genre: ");
          //Serial.println(mystr);
          genre= mystr;
          break;
      }
      free(attr_text);
  }break;
    default:
      ESP_LOGE(BT_RC_CT_TAG, "unhandled AVRC event: %d", event);
      break;
  }
}

Seeing as up to 15 commands can be used. How would one go to include ESP_AVRC_MD_ATTR_PLAYING_TIME to get an audio.playingtime value to create a progess bar? Sadly i'm not very well versed in c++ or programming in general.