Opened 3 years ago
Closed 3 years ago
#5138 closed defect (wontfix)
[H264 Decoder] Missing B frame in the H264 decoded stream.
Reported by: | jbbetton | Owned by: | |
---|---|---|---|
Priority: | normal | Component: | avcodec |
Version: | git-master | Keywords: | h264 |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | yes | |
Analyzed by developer: | no |
Description
Summary of the bug:
I use the demuxing_decoding example to decode an H264 stream that contains different sizes of sub-GOP (dynamic B-Frames). The first five sub-GOPs have 3 B-Frames. The sixth sub-GOP has 7 B-Frames and is not decoded correctly.
How to reproduce:
./demuxing_decoding CNBC_3B_7B_in.264 CNBC_3B_7B_out.yuv CNBC_3B_7B_out.pcm ffmpeg version : git-master built on CentOS 6.6
Result :
Coded frame 24 is missing. It should be between coded frames 17 and 23.
Attachments (1)
Change History (8)
Changed 3 years ago by jbbetton
comment:1 Changed 3 years ago by cehoyos
- Keywords h264 added; H264 Decoder B-Frames removed
- Reproduced by developer set
- Status changed from new to open
comment:2 Changed 3 years ago by jbbetton
- Resolution set to fixed
- Status changed from open to closed
Thanks for the answer and the changesets.
comment:3 Changed 3 years ago by cehoyos
- Resolution fixed deleted
- Status changed from closed to reopened
I don't know if this ticket is valid or not or if it will be fixed or not, but it definitely isn't fixed.
comment:4 Changed 3 years ago by cehoyos
How was your sample recorded? Is this the original broadcast stream or did you reencode it?
comment:5 Changed 3 years ago by jbbetton
It's not the original stream. I reencoded it to have dynamic B-Frames.
comment:6 Changed 3 years ago by cehoyos
Which encoder supports dynamic B-frames?
comment:7 Changed 3 years ago by cehoyos
- Priority changed from important to normal
- Resolution set to wontfix
- Status changed from reopened to closed
A message is shown since 69dbecf920f6fe7e5a7fc0b38ecaeeb444bc1d7a that tells the user about the increasing reorder buffer by default.
I believe the default behaviour will not change as long as no encoder supports dynamic B-frames.
For future tickets: Please do not report a ticket with ffplay, ffprobe or demuxing_decoding if it is reproducible with ffmpeg.
Currently needs -strict 1, related to 10e55bd658b06034d700553190b419b1af92b7cb / b09ad37c83841c399abb7f2503a2ab214d0c2d48
61 output frames are bitexact compared with the reference decoder.