tf_level 4 Defect

[Jigsawbg]

When using the following settings for hevc_nvenc:
-tune 5
-tf_level 4
-lookahead_level 15
The output file is reported as "isTruncated" in MediaInfo. The usual statistics(-stats) after the end of encoding are not displayed. It seems that shortly before it finishes encoding ffmpeg crashes silently. In the log file generated by -report the encoding appears incomplete.

With -tf_level 0 , everything seems fine.

The problem also exists in version ffmpeg-git-full 2024-04-15-git-5e380bcdb1.

Update:

Actually, the problem is not in tf_level 4 per se. The problem occurs when I use:

-hwaccel cuda -hwaccel_output_format cuda or -hwaccel cuda or -hwaccel nvdec or -hwaccel dxva2 or hwaccel auto. . . I tested with these.

If I use -c:v h264_cuvid then no problem.

This is enough to recreate the problem:

ffmpeg.exe -hwaccel auto -i input.m2ts -map 0:v:0 -c:v hevc_nvenc -bf 4 -tf_level 4 output.mkv

That's how it works:

ffmpeg.exe -c:v h264_cuvid -i input.m2ts -map 0:v:0 -c:v hevc_nvenc -bf 4 -tf_level 4 output.mkv

I'm on Windows 10 pro 22H2 OS build 19045.4291
Nvidia RTX 3060Ti Founders Edition
Driver 551.86