dashdemux: Subtract the period start time from the presentation offset

We're interested in the offset between the period start timestamp and the
actual media timestamp so that we can properly correct for it. The absolute
presentation offset to timestamp 0 is useless as the only thing we really
care about is the offset between the current fragment timestamp and the
media timestamp.

diff --git a/ext/dash/gstmpdparser.c b/ext/dash/gstmpdparser.c
index d5f9956..e7420ec 100644 (file)
--- a/ext/dash/gstmpdparser.c
+++ b/ext/dash/gstmpdparser.c
@@ -3761,13 +3761,17 @@ gst_mpd_parser_get_stream_presentation_offset (GstMpdClient * client,
     guint stream_idx)
 {
   GstActiveStream *stream = NULL;
+  GstStreamPeriod *stream_period = gst_mpdparser_get_stream_period (client);
 
   g_return_val_if_fail (client != NULL, FALSE);
   g_return_val_if_fail (client->active_streams != NULL, FALSE);
   stream = g_list_nth_data (client->active_streams, stream_idx);
   g_return_val_if_fail (stream != NULL, FALSE);
 
-  return stream->presentationTimeOffset;
+  if (stream->presentationTimeOffset > stream_period->start)
+    return stream->presentationTimeOffset - stream_period->start;
+  else
+    return 0;
 }
 
 gboolean