// get info about the stream
  GList* streaminfo;
  g_object_get(G_OBJECT(playbin), "stream-info", &streaminfo, NULL);
                 
  for( ; streaminfo != NULL; streaminfo = streaminfo->next) {
    GObject* info = (GObject*) streaminfo->data;
                 
                 
    typedef enum {
      GST_STREAM_TYPE_UNKNOWN = 0,
      GST_STREAM_TYPE_AUDIO   = 1,
      GST_STREAM_TYPE_VIDEO   = 2,
      GST_STREAM_TYPE_TEXT    = 3,
    } GstStreamType;
                 

    int type;
    g_object_get(info, "type", &type, NULL);
                 
    switch(type) {
      case GST_STREAM_TYPE_AUDIO: {
        break;
      }

      // video
      case GST_STREAM_TYPE_VIDEO: {
        break;
      }
    }

    char* decoder;
    char* codec;

    g_object_get(info, "decoder", &decoder, "codec", &codec, NULL);

    if(decoder == NULL && codec == NULL) {
       std::cout << "error while getting stream-info" << std::endl;
       return 1;
    }

    std::cout << "decoder: " << decoder << std::endl;
    std::cout << "codec: " << codec << std::endl;
  }
  g_list_free(streaminfo);