NVDEC - quality degradation with adaptive deinterlace since 535 drivers

We have observed large quality degradation when using ADAPTIVE deinterlace, i did some regression testing :
470 - not affected
510 - not affected
515 - not affected
525 - not affected
535 - affected
545 - affected

HW used: RTX 2060 Super, RTX 2070, Quadro RTX 4000, RTX 3050

There is image which will show very bad results on 535 drivers.

Bob and Weave deinterlace is not affected


Is this still a problem with 551?

Problem still present. HW deinterlace was broken more than a year ago (since 530 series) and still not fixed.

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It looks like it is fixed in 550.54.14 drivers, can anyone else confirm this?

@Thunderm I can confirm it is fixed in 550.54.14
nvidia-deinterlace-problem-535.154.05-550.54.14.zip (1.2 MB)
(left: 535.154.05, right: 550.54.14)


There is other issue on 550.76 drivers, when using different viewport resolution (1920x1080 → 1280x720) and format yuv420p(tv, bt470bg, top first) with adaptive deinterlace, on latest ffmpeg it will not even start, do you need more info, or is this known issue?

Can you share exact steps to reproduce this issue and any relevant files required to reproduce? Thanks.

Used command (BROKEN since 535 drivers):
ffmpeg -drop_second_field 1 -deint adaptive -resize 1280x720 -c:v h264_cuvid -i in.mp4 -c:v h264_nvenc -b:v 1M out.mp4

Command without using different ulTargetWidth and ulTargetHeight (CORRECT):
ffmpeg -drop_second_field 1 -deint adaptive -c:v h264_cuvid -i in.mp4 -c:v h264_nvenc -b:v 1M out.mp4

ffmpeg version is current stable, but it is observed on version 3-7


Output (broken):

Detail image of broken output:

What is that detailed image of broken output? I do not get it?

Your file has warning about 5 reference frames used in CABAC if I ffplay it, while it signals only 4 are in use. That is bad.

Stream could be somehow not perfectly valid, but anyway drivers 525 and lower will decode and deinterlace this sample without any issues.

I could check another stream 1080i50, but i think wrong REF frames is not reason for this issue. Should i check it on other stream?

5 reference frames is a different preset and profile theoretically.

Also not even allowed on blu-ray. Please test another.

Maybe 5 reference frames are even more rare for legacy interlaced content.

It is same with another correct sample as broken is deinterlace part, not decoding part.

Write if you need more tests…