mxfdemux: Add keyframe detection for MPEG2 video streams

This is useful for seeking as we usually want to seek to the previous
keyframe. The keyframe detection is done by parsing the MPEG2
elementary stream and if a GOP or I-frame packet is found we
assume a keyframe in this edit unit.

1 files changed, 7 insertions, 0 deletions

diff --git a/gst/mxf/mxfd10.c b/gst/mxf/mxfd10.c
index c24d163c..1195d3b4 100644
--- a/gst/mxf/mxfd10.c
+++ b/gst/mxf/mxfd10.c
@@ -30,6 +30,8 @@
 
 #include "mxfd10.h"
 
+#include "mxfmpeg.h"
+
 GST_DEBUG_CATEGORY_EXTERN (mxf_debug);
 #define GST_CAT_DEFAULT mxf_debug
 
@@ -81,6 +83,11 @@ mxf_d10_picture_handle_essence_element (const MXFUL * key, GstBuffer * buffer,
     return GST_FLOW_ERROR;
   }
 
+  if (mxf_mpeg_is_mpeg2_keyframe (buffer))
+    GST_BUFFER_FLAG_UNSET (buffer, GST_BUFFER_FLAG_DELTA_UNIT);
+  else
+    GST_BUFFER_FLAG_SET (buffer, GST_BUFFER_FLAG_DELTA_UNIT);
+
   return GST_FLOW_OK;
 }