dashdemux: Fix issue when manifest update sets slow start without passing necessary header & caps changes downstream

https://bugzilla.gnome.org/show_bug.cgi?id=777206

2 files changed, 30 insertions, 0 deletions

diff --git a/ext/dash/gstdashdemux.c b/ext/dash/gstdashdemux.c
index f6f812f6b..2ba32fc54 100644
--- a/ext/dash/gstdashdemux.c
+++ b/ext/dash/gstdashdemux.c
@@ -713,6 +713,7 @@ gst_dash_demux_setup_all_streams (GstDashDemux * demux)
           (stream), tags);
     stream->index = i;
     stream->pending_seek_ts = GST_CLOCK_TIME_NONE;
+    stream->last_representation_id = NULL;
     if (active_stream->cur_adapt_set &&
         active_stream->cur_adapt_set->RepresentationBase &&
         active_stream->cur_adapt_set->RepresentationBase->ContentProtection) {
@@ -1152,6 +1153,33 @@ gst_dash_demux_stream_update_fragment_info (GstAdaptiveDemuxStream * stream)
 
   if (gst_mpd_client_get_next_fragment_timestamp (dashdemux->client,
           dashstream->index, &ts)) {
+    if (gst_mpd_client_is_live (dashdemux->client)) {
+      if (!GST_ADAPTIVE_DEMUX_STREAM_NEED_HEADER (stream)) {
+        if (dashstream->active_stream
+            && dashstream->active_stream->cur_representation) {
+          /* id specifies an identifier for this Representation. The
+           * identifier shall be unique within a Period unless the
+           * Representation is functionally identically to another
+           * Representation in the same Period. */
+          if (!g_strcmp0 (dashstream->active_stream->cur_representation->id,
+                  dashstream->last_representation_id)) {
+            GstCaps *caps;
+            stream->need_header = TRUE;
+
+            GST_INFO_OBJECT (dashdemux, "Switching bitrate to %d",
+                dashstream->active_stream->cur_representation->bandwidth);
+            caps =
+                gst_dash_demux_get_input_caps (dashdemux,
+                dashstream->active_stream);
+            gst_adaptive_demux_stream_set_caps (stream, caps);
+          }
+        }
+      }
+      g_free (dashstream->last_representation_id);
+      dashstream->last_representation_id =
+          g_strdup (dashstream->active_stream->cur_representation->id);
+    }
+
     if (GST_ADAPTIVE_DEMUX_STREAM_NEED_HEADER (stream)) {
       gst_adaptive_demux_stream_fragment_clear (&stream->fragment);
       gst_dash_demux_stream_update_headers_info (stream);
@@ -2739,6 +2767,7 @@ gst_dash_demux_stream_free (GstAdaptiveDemuxStream * stream)
     gst_isoff_moof_box_free (dash_stream->moof);
   if (dash_stream->moof_sync_samples)
     g_array_free (dash_stream->moof_sync_samples, TRUE);
+  g_free (dash_stream->last_representation_id);
 }
 
 static GstDashDemuxClockDrift *
diff --git a/ext/dash/gstdashdemux.h b/ext/dash/gstdashdemux.h
index 0757d76b1..2bbd4f18b 100644
--- a/ext/dash/gstdashdemux.h
+++ b/ext/dash/gstdashdemux.h
@@ -96,6 +96,7 @@ struct _GstDashDemuxStream
 
   guint64 moof_average_size, first_sync_sample_average_size;
   gboolean first_sync_sample_after_moof, first_sync_sample_always_after_moof;
+  gchar *last_representation_id;
 };
 
 /**