Add skip_to_keyframe stream variable.

This replaces the matroskadec one with the same name.
The advantage is not only easier reuse in other demuxers
but also that we can make the decisions after the parser.
This fixes seeking in files that mark the keyframes incorrectly,
for example the file in track ticket #1003.
The matroska variable is still kept to be able to complain
about such broken files.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>

1 files changed, 6 insertions, 0 deletions

diff --git a/libavformat/utils.c b/libavformat/utils.c
index 3c3ced75a0..0636742b4e 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1315,6 +1315,12 @@ static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
             /* free packet */
             av_free_packet(&cur_pkt);
         }
+        if (pkt->flags & AV_PKT_FLAG_KEY)
+            st->skip_to_keyframe = 0;
+        if (st->skip_to_keyframe) {
+            av_free_packet(&cur_pkt);
+            got_packet = 0;
+        }
     }
 
     if (!got_packet && s->parse_queue)