[Regression] HEVC decoding error for those of image based subtitles

[planetrocky]

Summary of the bug:
How to reproduce:

% ffmpeg -i input.mp4 output.mp4
% ffmpeg -i input.mp4 -an -dn -sn output.mp4
% ffmpeg -i input.mkv output.mkv
% ffmpeg -i input.mkv -an -dn -sn output.mkv

ffmpeg versions built since approximately 2025-02-02 git master are broken;

ffmpeg-2025-01-22-git-e20ee9f9ae works and processes all the file that fail above (I have about 40x files that break).

Log attached shows log from -report, the error logs extracted here:

` sh
[vist#0:0/hevc @ 000001e7847c7b00] [dec:hevc @ 000001e7847c4280] Error processing packet in decoder: File exists
[vist#0:0/hevc @ 000001e7847c7b00] [dec:hevc @ 000001e7847c4280] Task finished with error code: -17 (File exists)
[vist#0:0/hevc @ 000001e7847c7b00] [dec:hevc @ 000001e7847c4280] Terminating thread with return code -17 (File exists)
[vost#0:0/libx264 @ 000001e78483c300] [enc:libx264 @ 000001e785216b00] Could not open encoder before EOF
[vost#0:0/libx264 @ 000001e78483c300] Task finished with error code: -22 (Invalid argument)
[vost#0:0/libx264 @ 000001e78483c300] Terminating thread with return code -22 (Invalid argument)
[out#0/matroska @ 000001e7847c7e80] Nothing was written into output file, because at least one of its streams received no packets.
`

[planetrocky]

ffmpeg report

[planetrocky]

1 second clip that demonstrates the HEVC error

[planetrocky]

ffmpeg -i Sample.mkv output.mkv breaks with same erorr on the 1-second sample attached

[Chris]

I have multiple users also experiencing this issue and confirmed that it is caused with a HEVC video with image based subtitles. Another example video in thread:

​https://github.com/cdgriffith/FastFlix/issues/633

[MasterQuestionable]

͏    Regression window:
͏    ​https://github.com/FFmpeg/FFmpeg/commits/master/libavcodec?since=2025-01-22&until=2025-02-02
͏    ​https://github.com/search?type=commits&q=repo:FFmpeg/FFmpeg+committer-date:>2025-01-22T15:15:18Z+hevc&s=committer-date&o=asc

[James]

Fixed in 8e6032990cdad1d8455ffd24d4fec20fcc78a3e2.