demux, stream: change metadata notification

(Again.)

This time, we simply make it event-based, as it should be. This is done
for both demuxer metadata and stream metadata.

For some ogg-over-icy streams, 2 updates are reported on stream start.
This is because libavformat reports an update right on start, while
including the same info in the "static" metadata. I don't know if that's
a bug or a feature.

1 files changed, 9 insertions, 1 deletions

diff --git a/demux/demux.h b/demux/demux.h
index df1762eb08..3929e23c94 100644
--- a/demux/demux.h
+++ b/demux/demux.h
@@ -87,6 +87,10 @@ enum demux_check {
     DEMUX_CHECK_NORMAL, // normal, safe detection
 };
 
+enum demux_event {
+    DEMUX_EVENT_METADATA = (1 << 0),
+};
+
 #define MAX_SH_STREAMS 256
 
 struct demuxer;
@@ -181,6 +185,9 @@ typedef struct demuxer {
     bool ts_resets_possible;
     bool warned_queue_overflow;
 
+    // Bitmask of DEMUX_EVENT_*
+    int events;
+
     struct sh_stream **streams;
     int num_streams;
     bool stream_autoselect;
@@ -203,7 +210,8 @@ typedef struct demuxer {
     struct playlist *playlist;
 
     struct mp_tags *metadata;
-    char *previous_metadata;
+
+    struct mp_tags *stream_metadata;
 
     void *priv;   // demuxer-specific internal data
     struct MPOpts *opts;