Reimplement dynamic metadata handling

This has been tested for both playback of streams and
outputting to streams, and seems to work fine with minimal
locking.  This reuses the sequence number infrastructure
in OutputBuffer for synchronizing metadata payloads; so
(IMNSHO) should be much more understandable than various
flags being set here and there..

It could still use some cleanup and much testing, but
synchronization issues should be minimal.

1 files changed, 29 insertions, 7 deletions

diff --git a/src/outputBuffer.c b/src/outputBuffer.c
index 7e899e574..ff3a8e901 100644
--- a/src/outputBuffer.c
+++ b/src/outputBuffer.c
@@ -70,8 +70,8 @@ struct output_buffer {
 	size_t conv_buf_len;
 	pthread_t thread;
 	ConvState conv_state;
-	unsigned int seq_drop;
-	unsigned int seq_player; /* only gets changed by ob.thread */
+	mpd_uint8 seq_drop;
+	mpd_uint8 seq_player; /* only gets changed by ob.thread */
 	mpd_uint8 seq_decoder; /* only gets changed by dc.thread */
 	struct ringbuf preseek_index;
 	enum ob_state preseek_state;
@@ -154,7 +154,7 @@ static enum action_status ob_do_drop(void)
 {
 	struct iovec vec[2];
 	long i;
-	unsigned int seq_drop;
+	mpd_uint8 seq_drop;
 
 	cond_enter(&ob_seq_cond);
 	seq_drop = ob.seq_drop;
@@ -202,9 +202,10 @@ static void reader_reset_buffer(void)
 		c->len = 0;
 	}
 	ringbuf_read_advance(ob.index, nr);
+	metadata_pipe_clear();
 }
 
-static void ob_seq_player_set(unsigned int seq_num)
+static void ob_seq_player_set(mpd_uint8 seq_num)
 {
 	cond_enter(&ob_seq_cond);
 	ob.seq_player = seq_num;
@@ -222,7 +223,7 @@ static enum action_status ob_do_reset(int close)
 	if (close)
 		closeAudioDevice();
 	ob.xfade_state = XFADE_DISABLED;
-	ob_seq_player_set((unsigned int)ob.seq_decoder);
+	ob_seq_player_set(ob.seq_decoder);
 	return ob_finalize_action();
 }
 
@@ -277,7 +278,7 @@ static enum action_status ob_do_seek_finish(void)
 		ob.total_time = dc.total_time;
 		reader_reset_buffer();
 		dropBufferedAudio();
-		ob_seq_player_set((unsigned int)ob.seq_decoder);
+		ob_seq_player_set(ob.seq_decoder);
 	}
 	return ob_finalize_action();
 }
@@ -398,12 +399,31 @@ static void new_song_chunk(struct ob_chunk *a)
 	ob.xfade_state = XFADE_DISABLED;
 	ob.total_time = dc.total_time;
 	/* DEBUG("ob.total_time: %f\n", ob.total_time); */
-	ob_seq_player_set((unsigned int)a->seq);
+	ob_seq_player_set(a->seq);
 	wakeup_main_task(); /* sync playlist */
 }
 
 #include "outputBuffer_audio.h"
 
+static void send_next_tag(void)
+{
+	static MpdTag *last_tag;
+	MpdTag *tag;
+
+	if ((tag = metadata_pipe_recv())) { /* streaming tag */
+		DEBUG("Caught new metadata! %p\n", tag);
+		sendMetadataToAudioDevice(tag);
+		freeMpdTag(tag);
+		wakeup_main_task(); /* call sync_metadata() in playlist.c */
+	} else if ((tag = playlist_current_tag())) { /* static file tag */
+		/* shouldn't need mpdTagsAreEqual here for static tags */
+		if (last_tag != tag) {
+			sendMetadataToAudioDevice(tag);
+			last_tag = tag;
+		}
+	}
+}
+
 static void play_next_chunk(void)
 {
 	struct iovec vec[2];
@@ -459,6 +479,8 @@ static void play_next_chunk(void)
 			return;
 		new_song_chunk(a);
 	}
+	send_next_tag();
+
 	/* pcm_volumeChange(a->data, a->len, &ob.audio_format, ob.sw_vol); */
 	if (playAudio(a->data, a->len) < 0)
 		stop_playback();