videodecoder: handle buffer's flags at offset

For reverse playback it is important to handle correctly the frame sync
points, which is set when the input buffer doesn't have the DELTA_UNIT flag.

This is handled correctly when decoder is packetized, but when it is not the
frame's sync point is not copied, and the reverse playback never decodes frame
batches.

The current patch adds the buffer's flags to the Timestamp list, where the
timestamp and duration of the input buffers are hold.

diff --git a/gst-libs/gst/video/gstvideodecoder.c b/gst-libs/gst/video/gstvideodecoder.c
index 3dd82f0..da00a8b 100644 (file)
--- a/gst-libs/gst/video/gstvideodecoder.c
+++ b/gst-libs/gst/video/gstvideodecoder.c
@@ -216,7 +216,7 @@
  *   gather queue:  9  8  7
  *                        D
  *
- * Whe buffer 4 is received (with a DISCONT), we flush the gather queue like
+ * When buffer 4 is received (with a DISCONT), we flush the gather queue like
  * this:
  *
  *   while (gather)
@@ -1975,6 +1975,7 @@ struct _Timestamp
   GstClockTime pts;
   GstClockTime dts;
   GstClockTime duration;
+  guint flags;
 };
 
 static void
@@ -2001,6 +2002,7 @@ gst_video_decoder_add_timestamp (GstVideoDecoder * decoder, GstBuffer * buffer)
   ts->pts = GST_BUFFER_PTS (buffer);
   ts->dts = GST_BUFFER_DTS (buffer);
   ts->duration = GST_BUFFER_DURATION (buffer);
+  ts->flags = GST_BUFFER_FLAGS (buffer);
 
   priv->timestamps = g_list_append (priv->timestamps, ts);
 }
@@ -2008,7 +2010,7 @@ gst_video_decoder_add_timestamp (GstVideoDecoder * decoder, GstBuffer * buffer)
 static void
 gst_video_decoder_get_timestamp_at_offset (GstVideoDecoder *
     decoder, guint64 offset, GstClockTime * pts, GstClockTime * dts,
-    GstClockTime * duration)
+    GstClockTime * duration, guint * flags)
 {
 #ifndef GST_DISABLE_GST_DEBUG
   guint64 got_offset = 0;
@@ -2019,6 +2021,7 @@ gst_video_decoder_get_timestamp_at_offset (GstVideoDecoder *
   *pts = GST_CLOCK_TIME_NONE;
   *dts = GST_CLOCK_TIME_NONE;
   *duration = GST_CLOCK_TIME_NONE;
+  *flags = 0;
 
   g = decoder->priv->timestamps;
   while (g) {
@@ -2030,6 +2033,7 @@ gst_video_decoder_get_timestamp_at_offset (GstVideoDecoder *
       *pts = ts->pts;
       *dts = ts->dts;
       *duration = ts->duration;
+      *flags = ts->flags;
       g = g->next;
       decoder->priv->timestamps = g_list_remove (decoder->priv->timestamps, ts);
       timestamp_free (ts);
@@ -3355,6 +3359,7 @@ gst_video_decoder_have_frame (GstVideoDecoder * decoder)
   GstBuffer *buffer;
   int n_available;
   GstClockTime pts, dts, duration;
+  guint flags;
   GstFlowReturn ret = GST_FLOW_OK;
 
   GST_LOG_OBJECT (decoder, "have_frame");
@@ -3371,11 +3376,16 @@ gst_video_decoder_have_frame (GstVideoDecoder * decoder)
   priv->current_frame->input_buffer = buffer;
 
   gst_video_decoder_get_timestamp_at_offset (decoder,
-      priv->frame_offset, &pts, &dts, &duration);
+      priv->frame_offset, &pts, &dts, &duration, &flags);
 
   GST_BUFFER_PTS (buffer) = pts;
   GST_BUFFER_DTS (buffer) = dts;
   GST_BUFFER_DURATION (buffer) = duration;
+  GST_BUFFER_FLAGS (buffer) = flags;
+
+  if (!GST_BUFFER_FLAG_IS_SET (buffer, GST_BUFFER_FLAG_DELTA_UNIT)) {
+    GST_VIDEO_CODEC_FRAME_SET_SYNC_POINT (priv->current_frame);
+  }
 
   GST_LOG_OBJECT (decoder, "collected frame size %d, "
       "PTS %" GST_TIME_FORMAT ", DTS %" GST_TIME_FORMAT ", dur %"