Opened 7 years ago

Closed 3 years ago

#4365 closed defect (needs_more_info)

Multithreaded slice decoding in HEVC producing incorrect output

Reported by: Christophe Owned by:
Priority: important Component: avcodec
Version: git-master Keywords: HEVC regression
Cc: jsantiago@fastmail.us Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

When using the appropriate sequence (containing slices or wavefronts), that kind of command-line produce varying CRCs:
./ffmpeg -threads 12 -thread_type slice -i <seq> -an -sn -f crc -

The expected output is a constant CRC, indicating valid decoding. This is what happends when 1 thread is used, or thread type is frame.

This is a regression since cf92cc8. The commit in itself can cause crashes, and to test it, 7117547 is required. I'm unfortunately not sure if any other commit/fix is required. Note that the code has changed much since cf92cc8, but the issue is still present.

The sequence on which I observed it is unfortunately not distribuable, and I don't know what freely distribuable sequence would exhibit the issue.

Change History (7)

comment:1 by Christophe, 7 years ago

Cc: christophe.gisquet@gmail.com added
Version: unspecifiedgit-master

comment:2 by Carl Eugen Hoyos, 6 years ago

Keywords: regression added
Priority: normalimportant

Please provide an input sample that allows to reproduce this issue.

comment:3 by Carl Eugen Hoyos, 6 years ago

Is this problem still reproducible? Ronald fixed a bug that may be related.

comment:4 by Jose Santiago, 5 years ago

Cc: jsantiago@fastmail.us added

comment:5 by Christophe, 5 years ago

Cc: christophe.gisquet@gmail.com removed

comment:6 by Carl Eugen Hoyos, 5 years ago

Would you mind telling us if the issue is still reproducible?

comment:7 by Elon Musk, 3 years ago

Resolution: needs_more_info
Status: newclosed
Note: See TracTickets for help on using tickets.