"hevc_cuvid" did not correctly decode H.265 video

[yuhongl]

Summary of the bug: hevc_cuvid does not correctly decode h265 video, but hevc correctly decode h265 video.
How to reproduce:

% ffmpeg -loglevel warning -hwaccel cuda -hwaccel_device 0  -vcodec hevc_cuvid -i h265.mp4 output_cuvid.mp4

% ffmpeg -loglevel warning -hwaccel cuda -hwaccel_device 0  -vcodec hevc -i h265.mp4 output_hevc.mp4
ffmpeg version: master branch, hash tag: d89930f8666c563a96f1dc1835b450522b4cd6da
built on:
  Ubuntu 20.04.6 LTS
  ./configure --enable-cuda --enable-cuvid --enable-nvdec --enable-nvenc --enable-nonfree --enable-libnpp --extra-cflags=-I/usr/local/cuda/include  --extra-ldflags=-L/usr/local/cuda/lib64 --disable-x86asm

The file output_cuvid.mp4 is wrong, output_hevc.mp4 is correct.

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[yuhongl]

Video file uploaded to streams.videolan.org. File name is h265.mp4

[MasterQuestionable]

͏    ​https://streams.videolan.org/ffmpeg/incoming/11158/h265.mp4
͏    (~ 98.97 MiB)

[Balling]

You are not allowed to use both hwaccel and HW decoder, or use vcodec in ffmpeg, only in ffplay, since it has no c:v option:

ffplay.exe -vcodec hevc_cuvid -i ​https://streams.videolan.org/ffmpeg/incoming/11158/h265.mp4

or

ffmpeg.exe -c:v hevc_cuvid -i ​https://streams.videolan.org/ffmpeg/incoming/11158/h265.mp4 -frames:v 1 -crf 0 -cpu-used 0 file.avif

But yes some issue is there.

[yuhongl]

Hi Balling, can you please help me to delete the mp4 file from ​https://streams.videolan.org/ffmpeg/incoming/11158/h265.mp4, then I will close the ticket.

[Balling]

This looks like a real bug, why do you want to close it, and I imagine the samples from the our sample directory cannot be removed, even with DMCA (?).

[yuhongl]

It shows some license plates, which are not masked by my mistake, so I would like to delete it and close the ticket.

[Balling]

Is #11324 also you?

[yuhongl]

We found the bug is related to Nvidia's GPU video decoder. We already contacted Nvidia about it. We had the video deleted from Videolan, so the ticket is closed as wontfix.