[FFmpeg-devel] [PATCH RFC 0/6] MP4 editlist and HEVC decoder

[Zhao Zhili]

From: Zhao Zhili <zhilizhao at tencent.com>

Fix #11510

#11510 revealed multiple issues related to mp4 demuxer, hevc decoder
and videotoolbox.

1. mp4 demuxer output packets have rewind due to editlist,

POC		 POC
916 -----------> 944

then rewind back to

916 -----------> 944 942

2. Both POC 916 and POC 944 are CRA nalu, so no flush on output.

3. When decoding POC the second time, POC still inside DPB buffer.

Patch 1/6 fix videotoolbox which shouldn't reset when confronted with
    ReferenceMissingErr

Patch 2/6 is trial.

Patch 3/6 allow duplicated POC in DPB buffer. I'm not quite sure the
side effect.

Patch 4 to 6 add a flag to indicate the start of a new sequence, so
the decoder can flush on output. I know it looks suspicious, please
comment.

There are more general stream rewind issues to be resolved.

Zhao Zhili (6):
  avcodec/vt: Don't restart decoder when confronted with
    ReferenceMissingErr
  avformat/mov: generalize sgpd_sync index lookup
  avcodec/hevc: Don't drop packet with duplicate POC
  avcodec/packet: Add AV_PKT_FLAG_NEW_SEQUENCE flag
  avformat/mov: Notify new sequence at the start of editlist
  avcodec/hevc: Check AV_PKT_FLAG_NEW_SEQUENCE and flush pictures out

 libavcodec/hevc/hevcdec.c |  3 +++
 libavcodec/hevc/refs.c    |  4 ++--
 libavcodec/packet.h       | 10 ++++++++++
 libavcodec/videotoolbox.c | 10 ++++++----
 libavformat/avformat.h    |  2 ++
 libavformat/mov.c         | 21 ++++++++++++++-------
 6 files changed, 37 insertions(+), 13 deletions(-)

-- 
2.46.0