mpegpsdemux: Send gap events for late streams whenever updating the SCR

Instead of doing it on each packet and doing it based on the distance to
the previous SCR instead of based on the DTS.

Previously we would send gap events for audio all the time if the SCR
distance was 400ms because the threshold for audio is 300ms and by only
ever updating the position when the SCR updates we would always be 100ms
above the threshold and send needless gap events.

This fixes audio glitches on various files caused by gap events.

diff --git a/gst/mpegdemux/gstmpegdemux.c b/gst/mpegdemux/gstmpegdemux.c
index 42bb15b..2f60414 100644 (file)
--- a/gst/mpegdemux/gstmpegdemux.c
+++ b/gst/mpegdemux/gstmpegdemux.c
@@ -663,26 +663,17 @@ gst_ps_demux_send_data (GstPsDemux * demux, GstPsStream * stream,
   GST_BUFFER_DTS (buf) = dts;
 
   /* update position in the segment */
-  gst_segment_set_position (&demux->src_segment, GST_FORMAT_TIME,
-      MPEGTIME_TO_GSTTIME (demux->current_scr - demux->first_scr));
-
-  GST_LOG_OBJECT (demux, "last stop position is now %" GST_TIME_FORMAT
-      " current scr is %" GST_TIME_FORMAT,
-      GST_TIME_ARGS (demux->src_segment.position),
-      GST_TIME_ARGS (MPEGTIME_TO_GSTTIME (demux->current_scr)));
-
-  if (demux->src_segment.position != GST_CLOCK_TIME_NONE &&
-      demux->base_time != GST_CLOCK_TIME_NONE) {
-    GstClockTime new_time = demux->base_time + demux->src_segment.position;
-
-    if (stream->last_ts == GST_CLOCK_TIME_NONE || stream->last_ts < new_time) {
-      GST_LOG_OBJECT (demux,
-          "last_ts update on pad %s to time %" GST_TIME_FORMAT,
-          GST_PAD_NAME (stream->pad), GST_TIME_ARGS (new_time));
-      stream->last_ts = new_time;
-    }
-
-    gst_ps_demux_send_gap_updates (demux, new_time);
+  if (stream->last_ts == GST_CLOCK_TIME_NONE || stream->last_ts < dts) {
+    GST_LOG_OBJECT (demux,
+        "last_ts update on pad %s to time %" GST_TIME_FORMAT
+        ", current scr is %" GST_TIME_FORMAT, GST_PAD_NAME (stream->pad),
+        GST_TIME_ARGS (dts),
+        GST_TIME_ARGS (MPEGTIME_TO_GSTTIME (demux->current_scr)));
+    stream->last_ts = dts;
+    if (demux->src_segment.position == GST_CLOCK_TIME_NONE
+        || stream->last_ts > demux->src_segment.position)
+      gst_segment_set_position (&demux->src_segment, GST_FORMAT_TIME,
+          stream->last_ts);
   }
 
   /* Set the buffer discont flag, and clear discont state on the stream */
@@ -944,6 +935,9 @@ gst_ps_demux_send_gap_updates (GstPsDemux * demux, GstClockTime new_start)
   gint i, count = demux->found_count;
   GstEvent *event = NULL;
 
+  if (new_start == GST_CLOCK_TIME_NONE)
+    return;
+
   /* Advance all lagging streams by sending a gap event */
   if ((base_time = demux->base_time) == GST_CLOCK_TIME_NONE)
     base_time = 0;
@@ -969,8 +963,9 @@ gst_ps_demux_send_gap_updates (GstPsDemux * demux, GstClockTime new_start)
         gst_ps_demux_send_segment (demux, stream, GST_CLOCK_TIME_NONE);
 
         GST_LOG_OBJECT (demux,
-            "Sending gap update to pad %s time %" GST_TIME_FORMAT,
-            GST_PAD_NAME (stream->pad), GST_TIME_ARGS (new_start));
+            "Sending gap update to pad %s from time %" GST_TIME_FORMAT " to %"
+            GST_TIME_FORMAT, GST_PAD_NAME (stream->pad),
+            GST_TIME_ARGS (stream->last_ts), GST_TIME_ARGS (new_start));
         event =
             gst_event_new_gap (stream->last_ts, new_start - stream->last_ts);
         gst_pad_push_event (stream->pad, event);
@@ -1851,6 +1846,12 @@ gst_ps_demux_parse_pack_start (GstPsDemux * demux)
   gst_adapter_unmap (demux->adapter);
   gst_adapter_flush (demux->adapter, length);
   ADAPTER_OFFSET_FLUSH (length);
+
+  /* Now check for all streams if they're behind the new SCR and if
+   * they are then move them forward to the SCR position */
+  gst_ps_demux_send_gap_updates (demux,
+      MPEGTIME_TO_GSTTIME (demux->current_scr - demux->first_scr));
+
   return GST_FLOW_OK;
 
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