decoder_api: added decoder_tag()

Provide an API for submitting additional tags from the stream.

src/decoder/oggvorbis_plugin.c

@@ -179,7 +179,9 @@ static struct tag *oggCommentsParse(char **comments)
 	return tag;
 }
 
-static void putOggCommentsIntoOutputBuffer(char *streamName,
+static void putOggCommentsIntoOutputBuffer(struct decoder *decoder,
+					   struct input_stream *is,
+					   char *streamName,
 					   char **comments)
 {
 	struct tag *tag;
@@ -196,6 +198,7 @@ static void putOggCommentsIntoOutputBuffer(char *streamName,
 		tag_add_item(tag, TAG_ITEM_NAME, streamName);
 	}
 
+	decoder_tag(decoder, is, tag);
 	tag_free(tag);
 }
 
@@ -284,7 +287,8 @@ oggvorbis_decode(struct decoder *decoder, struct input_stream *inStream)
 				initialized = true;
 			}
 			comments = ov_comment(&vf, -1)->user_comments;
-			putOggCommentsIntoOutputBuffer(inStream->meta_name,
+			putOggCommentsIntoOutputBuffer(decoder, inStream,
+						       inStream->meta_name,
 						       comments);
 			ogg_getReplayGainInfo(comments, &replayGainInfo);
 		}

src/decoder_api.c

@@ -190,3 +190,16 @@ decoder_data(struct decoder *decoder,
 
 	return DECODE_COMMAND_NONE;
 }
+
+enum decoder_command
+decoder_tag(mpd_unused struct decoder *decoder, struct input_stream *is,
+	    const struct tag *tag)
+{
+	while (!music_pipe_tag(tag)) {
+		enum decoder_command cmd = need_chunks(is);
+		if (cmd != DECODE_COMMAND_NONE)
+			return cmd;
+	}
+
+	return DECODE_COMMAND_NONE;
+}

src/decoder_api.h

@@ -155,4 +155,15 @@ decoder_data(struct decoder *decoder,
 	     void *data, size_t datalen, float data_time, uint16_t bitRate,
 	     ReplayGainInfo * replayGainInfo);
 
+/**
+ * This function is called by the decoder plugin when it has
+ * successfully decoded a tag.
+ *
+ * @param is an input stream which is buffering while we are waiting
+ * for the player
+ */
+enum decoder_command
+decoder_tag(struct decoder *decoder, struct input_stream *is,
+	    const struct tag *tag);
+
 #endif