adaptivedemux: Fix playback of live streams

dashdemux seeks each live stream to its current fragment in the beginning, but
the base class does not know about this. Update the demuxer segment with this
seek so we generate the correct SEGMENT event and can actually play the
stream.

This needs some refactoring at some point.

https://bugzilla.gnome.org/show_bug.cgi?id=755047

1 files changed, 33 insertions, 7 deletions

diff --git a/gst-libs/gst/adaptivedemux/gstadaptivedemux.c b/gst-libs/gst/adaptivedemux/gstadaptivedemux.c
index 6e0d88dfd..d43fdc953 100644
--- a/gst-libs/gst/adaptivedemux/gstadaptivedemux.c
+++ b/gst-libs/gst/adaptivedemux/gstadaptivedemux.c
@@ -151,7 +151,8 @@ static void gst_adaptive_demux_updates_loop (GstAdaptiveDemux * demux);
 static void gst_adaptive_demux_stream_download_loop (GstAdaptiveDemuxStream *
     stream);
 static void gst_adaptive_demux_reset (GstAdaptiveDemux * demux);
-static gboolean gst_adaptive_demux_expose_streams (GstAdaptiveDemux * demux);
+static gboolean gst_adaptive_demux_expose_streams (GstAdaptiveDemux * demux,
+    gboolean first_and_live);
 static gboolean gst_adaptive_demux_is_live (GstAdaptiveDemux * demux);
 static GstFlowReturn gst_adaptive_demux_stream_seek (GstAdaptiveDemux * demux,
     GstAdaptiveDemuxStream * stream, GstClockTime ts);
@@ -510,7 +511,8 @@ gst_adaptive_demux_sink_event (GstPad * pad, GstObject * parent,
         }
 
         if (demux->next_streams) {
-          gst_adaptive_demux_expose_streams (demux);
+          gst_adaptive_demux_expose_streams (demux,
+              gst_adaptive_demux_is_live (demux));
           gst_adaptive_demux_start_tasks (demux);
           if (gst_adaptive_demux_is_live (demux)) {
             /* Task to periodically update the manifest */
@@ -736,11 +738,12 @@ gst_adaptive_demux_get_period_start_time (GstAdaptiveDemux * demux)
 }
 
 static gboolean
-gst_adaptive_demux_expose_streams (GstAdaptiveDemux * demux)
+gst_adaptive_demux_expose_streams (GstAdaptiveDemux * demux,
+    gboolean first_and_live)
 {
   GList *iter;
   GList *old_streams;
-  GstClockTime period_start;
+  GstClockTime period_start, min_pts = GST_CLOCK_TIME_NONE;
 
   g_return_val_if_fail (demux->next_streams != NULL, FALSE);
 
@@ -756,6 +759,29 @@ gst_adaptive_demux_expose_streams (GstAdaptiveDemux * demux)
             GST_ADAPTIVE_DEMUX_STREAM_CAST (stream))) {
       /* TODO act on error */
     }
+
+    if (first_and_live) {
+      /* TODO we only need the first timestamp, maybe create a simple function */
+      gst_adaptive_demux_stream_update_fragment_info (demux, stream);
+
+      if (GST_CLOCK_TIME_IS_VALID (min_pts)) {
+        min_pts = MIN (min_pts, stream->fragment.timestamp);
+      } else {
+        min_pts = stream->fragment.timestamp;
+      }
+    }
+  }
+
+  /* For live streams, the subclass is supposed to seek to the current
+   * fragment and then tell us its timestamp in stream->fragment.timestamp.
+   * We now also have to seek our demuxer segment to reflect this.
+   *
+   * FIXME: This needs some refactoring at some point.
+   */
+  if (first_and_live) {
+    gst_segment_do_seek (&demux->segment, demux->segment.rate, GST_FORMAT_TIME,
+        GST_SEEK_FLAG_FLUSH, GST_SEEK_TYPE_SET, min_pts, GST_SEEK_TYPE_NONE, -1,
+        NULL);
   }
 
   period_start = gst_adaptive_demux_get_period_start_time (demux);
@@ -1090,7 +1116,7 @@ gst_adaptive_demux_src_event (GstPad * pad, GstObject * parent,
       }
 
       if (demux->next_streams) {
-        gst_adaptive_demux_expose_streams (demux);
+        gst_adaptive_demux_expose_streams (demux, FALSE);
       } else {
         GList *iter;
         GstClockTime period_start =
@@ -2583,7 +2609,7 @@ gst_adaptive_demux_stream_advance_fragment_unlocked (GstAdaptiveDemux * demux,
       /* TODO only allow switching streams if other downloads are not ongoing */
       GST_DEBUG_OBJECT (demux, "Subclass wants new pads "
           "to do bitrate switching");
-      gst_adaptive_demux_expose_streams (demux);
+      gst_adaptive_demux_expose_streams (demux, FALSE);
       gst_adaptive_demux_start_tasks (demux);
       ret = GST_FLOW_EOS;
     }
@@ -2737,7 +2763,7 @@ gst_adaptive_demux_advance_period (GstAdaptiveDemux * demux)
 
   GST_DEBUG_OBJECT (demux, "Advancing to next period");
   klass->advance_period (demux);
-  gst_adaptive_demux_expose_streams (demux);
+  gst_adaptive_demux_expose_streams (demux, FALSE);
   gst_adaptive_demux_start_tasks (demux);
 }