dashdemux: support downloading segments in reverse order

When a seek with a negative rate is requested, find the target
segment where gstsegment.stop belongs in and then download from
this segment backwards until the first segment.

This allows proper reverse playback.

diff --git a/ext/dash/gstdashdemux.c b/ext/dash/gstdashdemux.c
index 605d607..a46e6ab 100644 (file)
--- a/ext/dash/gstdashdemux.c
+++ b/ext/dash/gstdashdemux.c
@@ -511,7 +511,10 @@ gst_dash_demux_src_event (GstPad * pad, GstObject * parent, GstEvent * event)
         gst_dash_demux_wait_stop (demux);
 
         /* select the requested Period in the Media Presentation */
-        target_pos = (GstClockTime) demux->segment.start;
+        if (demux->segment.rate > 0.0)
+          target_pos = (GstClockTime) demux->segment.start;
+        else
+          target_pos = (GstClockTime) demux->segment.stop;
         GST_DEBUG_OBJECT (demux, "Seeking to target %" GST_TIME_FORMAT,
             GST_TIME_ARGS (target_pos));
         current_period = 0;
@@ -2216,7 +2219,8 @@ gst_dash_demux_stream_download_fragment (GstDashDemux * demux,
   }
 
   g_mutex_lock (&stream->fragment_download_lock);
-  if (gst_mpd_client_get_next_fragment (demux->client, stream_idx, fragment)) {
+  if (gst_mpd_client_get_next_fragment (demux->client, stream_idx, fragment,
+          stream->demux->segment.rate > 0.0)) {
     GST_INFO_OBJECT (stream->pad,
         "Fetching next fragment %s ts:%" GST_TIME_FORMAT " dur:%"
         GST_TIME_FORMAT " Range:%" G_GINT64_FORMAT "-%" G_GINT64_FORMAT,

diff --git a/ext/dash/gstmpdparser.c b/ext/dash/gstmpdparser.c
index 0b3b5ec..29c8c1a 100644 (file)
--- a/ext/dash/gstmpdparser.c
+++ b/ext/dash/gstmpdparser.c
@@ -3574,7 +3574,7 @@ gst_mpd_client_get_next_fragment_timestamp (GstMpdClient * client,
 
 gboolean
 gst_mpd_client_get_next_fragment (GstMpdClient * client,
-    guint indexStream, GstMediaFragmentInfo * fragment)
+    guint indexStream, GstMediaFragmentInfo * fragment, gboolean forward)
 {
   GstActiveStream *stream = NULL;
   GstMediaSegment currentChunk;
@@ -3679,7 +3679,8 @@ gst_mpd_client_get_next_fragment (GstMpdClient * client,
     }
   }
 
-  gst_mpd_client_set_segment_index (stream, segment_idx + 1);
+  gst_mpd_client_set_segment_index (stream,
+      forward ? segment_idx + 1 : segment_idx - 1);
   GST_MPD_CLIENT_UNLOCK (client);
 
   GST_DEBUG ("Loading chunk with URL %s", fragment->uri);

diff --git a/ext/dash/gstmpdparser.h b/ext/dash/gstmpdparser.h
index 5d059b8..24755de 100644 (file)
--- a/ext/dash/gstmpdparser.h
+++ b/ext/dash/gstmpdparser.h
@@ -492,7 +492,7 @@ GstClockTime gst_mpd_client_get_next_fragment_duration (GstMpdClient * client, G
 GstClockTime gst_mpd_client_get_media_presentation_duration (GstMpdClient *client);
 gboolean gst_mpd_client_get_last_fragment_timestamp (GstMpdClient * client, guint stream_idx, GstClockTime * ts);
 gboolean gst_mpd_client_get_next_fragment_timestamp (GstMpdClient * client, guint stream_idx, GstClockTime * ts);
-gboolean gst_mpd_client_get_next_fragment (GstMpdClient *client, guint indexStream, GstMediaFragmentInfo * fragment);
+gboolean gst_mpd_client_get_next_fragment (GstMpdClient *client, guint indexStream, GstMediaFragmentInfo * fragment, gboolean forward);
 gboolean gst_mpd_client_get_next_header (GstMpdClient *client, gchar **uri, guint stream_idx, gint64 * range_start, gint64 * range_end);
 gboolean gst_mpd_client_get_next_header_index (GstMpdClient *client, gchar **uri, guint stream_idx, gint64 * range_start, gint64 * range_end);
 gboolean gst_mpd_client_is_live (GstMpdClient * client);