Add albumArtist and composer lists if available. Add a FramePosition property giving the RTP frame number and the time it is to be played. ASlso add a SetFramePositionUpdateInterval method to get it to be generated at intervals.

dbus-service.c

@@ -97,6 +97,16 @@ void dbus_metadata_watcher(struct metadata_bundle *argc, __attribute__((unused))
     }
   }
 
+  if (argc->frame_position_string) {
+    // debug(1, "Check frame position string");
+    th = shairport_sync_get_frame_position(shairportSyncSkeleton);
+    if ((th == NULL) || (strcasecmp(th, argc->frame_position_string) != 0)) {
+      // debug(1, "Frame position string should be changed");
+      shairport_sync_set_frame_position(shairportSyncSkeleton,
+                                                        argc->frame_position_string);
+    }
+  }
+
   if (argc->stream_type) {
     // debug(1, "Check stream type");
     th = shairport_sync_remote_control_get_stream_type(shairportSyncRemoteControlSkeleton);
@@ -243,7 +253,7 @@ void dbus_metadata_watcher(struct metadata_bundle *argc, __attribute__((unused))
     g_variant_builder_add(dict_builder, "{sv}", "xesam:album", album_name);
   }
 
-  // Add the artist name if it exists
+  // Add the artist name list if it exists
   if (argc->artist_name) {
     GVariantBuilder *artist_as = g_variant_builder_new(G_VARIANT_TYPE("as"));
     g_variant_builder_add(artist_as, "s", argc->artist_name);
@@ -252,7 +262,25 @@ void dbus_metadata_watcher(struct metadata_bundle *argc, __attribute__((unused))
     g_variant_builder_add(dict_builder, "{sv}", "xesam:artist", artists);
   }
 
-  // Add the genre if it exists
+  // Add the album artist list if it exists
+  if (argc->album_artist_name) {
+    GVariantBuilder *album_artist_as = g_variant_builder_new(G_VARIANT_TYPE("as"));
+    g_variant_builder_add(album_artist_as, "s", argc->album_artist_name);
+    GVariant *album_artists = g_variant_builder_end(album_artist_as);
+    g_variant_builder_unref(album_artist_as);
+    g_variant_builder_add(dict_builder, "{sv}", "xesam:albumArtist", album_artists);
+  }
+
+  // Add the composer list if it exists
+  if (argc->composer) {
+    GVariantBuilder *composer_as = g_variant_builder_new(G_VARIANT_TYPE("as"));
+    g_variant_builder_add(composer_as, "s", argc->composer);
+    GVariant *composers = g_variant_builder_end(composer_as);
+    g_variant_builder_unref(composer_as);
+    g_variant_builder_add(dict_builder, "{sv}", "xesam:composer", composers);
+  }
+
+  // Add the genre list if it exists
   if (argc->genre) {
     GVariantBuilder *genre_as = g_variant_builder_new(G_VARIANT_TYPE("as"));
     g_variant_builder_add(genre_as, "s", argc->genre);
@@ -835,6 +863,18 @@ static gboolean on_handle_drop_session(ShairportSync *skeleton, GDBusMethodInvoc
   return TRUE;
 }
 
+static gboolean on_handle_set_frame_position_update_interval(ShairportSync *skeleton,
+                                             GDBusMethodInvocation *invocation,
+                                             const gdouble seconds,
+                                             __attribute__((unused)) gpointer user_data) {
+  debug(1, ">> set frame position update interval to %.6f.", seconds);
+  config.metadata_progress_interval = seconds;
+  shairport_sync_complete_set_frame_position_update_interval(skeleton, invocation);
+  return TRUE;
+}
+
+
+
 static void on_dbus_name_acquired(GDBusConnection *connection, const gchar *name,
                                   __attribute__((unused)) gpointer user_data) {
 
@@ -893,6 +933,10 @@ static void on_dbus_name_acquired(GDBusConnection *connection, const gchar *name
   g_signal_connect(shairportSyncSkeleton, "handle-drop-session", G_CALLBACK(on_handle_drop_session),
                    NULL);
 
+  g_signal_connect(shairportSyncSkeleton, "handle-set-frame-position-update-interval",
+                   G_CALLBACK(on_handle_set_frame_position_update_interval),
+                   NULL);
+
   g_signal_connect(shairportSyncDiagnosticsSkeleton, "notify::verbosity",
                    G_CALLBACK(notify_verbosity_callback), NULL);
 
@@ -952,7 +996,7 @@ static void on_dbus_name_acquired(GDBusConnection *connection, const gchar *name
                                         config.loudness_reference_volume_db);
   shairport_sync_set_drift_tolerance(SHAIRPORT_SYNC(shairportSyncSkeleton), config.tolerance);
   shairport_sync_set_volume(SHAIRPORT_SYNC(shairportSyncSkeleton), config.airplay_volume);
-
+  
 #ifdef CONFIG_APPLE_ALAC
   if (config.use_apple_decoder == 0) {
     shairport_sync_set_alacdecoder(SHAIRPORT_SYNC(shairportSyncSkeleton), "hammerton");