matroskademux: fix sending of tags

* Fix critical when new tags are found after segment event has already
  been sent.
* Send global tags before stream tags.
* Split sending of tags out of gst_matroska_demux_send_event() into its
  own function.

https://bugzilla.gnome.org/show_bug.cgi?id=745973

gst/matroska/matroska-demux.c

@@ -1396,7 +1396,6 @@ gst_matroska_demux_handle_src_query (GstPad * pad, GstObject * parent,
 static gboolean
 gst_matroska_demux_send_event (GstMatroskaDemux * demux, GstEvent * event)
 {
-  gboolean is_segment;
   gboolean ret = FALSE;
   gint i;
 
@@ -1405,8 +1404,6 @@ gst_matroska_demux_send_event (GstMatroskaDemux * demux, GstEvent * event)
   GST_DEBUG_OBJECT (demux, "Sending event of type %s to all source pads",
       GST_EVENT_TYPE_NAME (event));
 
-  is_segment = (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
-
   g_assert (demux->common.src->len == demux->common.num_streams);
   for (i = 0; i < demux->common.src->len; i++) {
     GstMatroskaTrackContext *stream;
@@ -1415,19 +1412,18 @@ gst_matroska_demux_send_event (GstMatroskaDemux * demux, GstEvent * event)
     gst_event_ref (event);
     gst_pad_push_event (stream->pad, event);
     ret = TRUE;
-
-    /* FIXME: send global tags before stream tags */
-    if (G_UNLIKELY (is_segment && stream->pending_tags != NULL)) {
-      GST_DEBUG_OBJECT (demux, "Sending pending_tags %p for pad %s:%s : %"
-          GST_PTR_FORMAT, stream->pending_tags,
-          GST_DEBUG_PAD_NAME (stream->pad), stream->pending_tags);
-      gst_pad_push_event (stream->pad,
-          gst_event_new_tag (stream->pending_tags));
-      stream->pending_tags = NULL;
-    }
   }
 
-  if (G_UNLIKELY (is_segment && demux->common.global_tags != NULL)) {
+  gst_event_unref (event);
+  return ret;
+}
+
+static void
+gst_matroska_demux_send_tags (GstMatroskaDemux * demux)
+{
+  gint i;
+
+  if (G_UNLIKELY (demux->common.global_tags != NULL)) {
     GstEvent *tag_event;
     gst_tag_list_add (demux->common.global_tags, GST_TAG_MERGE_REPLACE,
         GST_TAG_CONTAINER_FORMAT, "Matroska", NULL);
@@ -1447,8 +1443,21 @@ gst_matroska_demux_send_event (GstMatroskaDemux * demux, GstEvent * event)
     demux->common.global_tags = NULL;
   }
 
-  gst_event_unref (event);
+  g_assert (demux->common.src->len == demux->common.num_streams);
-  return ret;
+  for (i = 0; i < demux->common.src->len; i++) {
+    GstMatroskaTrackContext *stream;
+
+    stream = g_ptr_array_index (demux->common.src, i);
+
+    if (G_UNLIKELY (stream->pending_tags != NULL)) {
+      GST_DEBUG_OBJECT (demux, "Sending pending_tags %p for pad %s:%s : %"
+          GST_PTR_FORMAT, stream->pending_tags,
+          GST_DEBUG_PAD_NAME (stream->pad), stream->pending_tags);
+      gst_pad_push_event (stream->pad,
+          gst_event_new_tag (stream->pending_tags));
+      stream->pending_tags = NULL;
+    }
+  }
 }
 
 static gboolean
@@ -4185,6 +4194,8 @@ gst_matroska_demux_parse_id (GstMatroskaDemux * demux, guint32 id,
             GST_READ_CHECK (gst_matroska_demux_take (demux, read, &ebml));
             ret = gst_matroska_read_common_parse_info (&demux->common,
                 GST_ELEMENT_CAST (demux), &ebml);
+            if (ret == GST_FLOW_OK)
+              gst_matroska_demux_send_tags (demux);
           } else {
             GST_READ_CHECK (gst_matroska_demux_flush (demux, read));
           }
@@ -4286,6 +4297,8 @@ gst_matroska_demux_parse_id (GstMatroskaDemux * demux, guint32 id,
             GST_READ_CHECK (gst_matroska_demux_take (demux, read, &ebml));
             ret = gst_matroska_read_common_parse_attachments (&demux->common,
                 GST_ELEMENT_CAST (demux), &ebml);
+            if (ret == GST_FLOW_OK)
+              gst_matroska_demux_send_tags (demux);
           } else {
             GST_READ_CHECK (gst_matroska_demux_flush (demux, read));
           }
@@ -4294,6 +4307,8 @@ gst_matroska_demux_parse_id (GstMatroskaDemux * demux, guint32 id,
           GST_READ_CHECK (gst_matroska_demux_take (demux, read, &ebml));
           ret = gst_matroska_read_common_parse_metadata (&demux->common,
               GST_ELEMENT_CAST (demux), &ebml);
+          if (ret == GST_FLOW_OK)
+            gst_matroska_demux_send_tags (demux);
           break;
         case GST_MATROSKA_ID_CHAPTERS:
           if (!demux->common.chapters_parsed) {

gst/matroska/matroska-read-common.c

@@ -447,25 +447,10 @@ gst_matroska_read_common_found_global_tag (GstMatroskaReadCommon * common,
     GstElement * el, GstTagList * taglist)
 {
   if (common->global_tags) {
-    /* nothing sent yet, add to cache */
     gst_tag_list_insert (common->global_tags, taglist, GST_TAG_MERGE_APPEND);
     gst_tag_list_unref (taglist);
   } else {
-    GstEvent *tag_event = gst_event_new_tag (taglist);
+    common->global_tags = taglist;
-    gint i;
-
-    /* hm, already sent, no need to cache and wait anymore */
-    GST_DEBUG_OBJECT (common->sinkpad,
-        "Sending late global tags %" GST_PTR_FORMAT, taglist);
-
-    for (i = 0; i < common->src->len; i++) {
-      GstMatroskaTrackContext *stream;
-
-      stream = g_ptr_array_index (common->src, i);
-      gst_pad_push_event (stream->pad, gst_event_ref (tag_event));
-    }
-
-    gst_event_unref (tag_event);
   }
 }
 
@@ -2402,6 +2387,9 @@ gst_matroska_read_common_parse_metadata_id_tag (GstMatroskaReadCommon * common,
         GstMatroskaTrackContext *stream = g_ptr_array_index (common->src, j);
 
         if (stream->uid == tgt) {
+          if (stream->pending_tags == NULL)
+            stream->pending_tags = gst_tag_list_new_empty ();
+
           gst_tag_list_insert (stream->pending_tags, taglist,
               GST_TAG_MERGE_REPLACE);
           found = TRUE;