qsv does not deinterlace properly

[s170361683]

(a sample is attached)

using 50i source, DXVA for decoding, and qsv for encoding, I thought by specifying rate=field and deinterlace=bob in vpp_qsv filter that each field would be transformed to a frame in a 50p output. But the result was just a non-smooth 50p file that feels like 25p with frames being doubled.

yadif with yadif=send_field produced the desired smooth 50p output

ffmpeg ^
    -hwaccel dxva2 ^
    -hwaccel_output_format dxva2_vld ^
    -i "50i_sample.m2v" ^
    -c:v h264_qsv ^
    -vf "hwmap=derive_device=qsv,vpp_qsv=rate=field:deinterlace=bob" ^
    -y output.mp4

ffmpeg version git-2023-09-18-fa20f5c-ffmpeg-windows-build-helpers Copyright (c) 2000-2023 the FFmpeg developers
  built with gcc 10.2.0 (GCC)

​wenbin.chen@intel.com

[wenbin,chen]

You can try "deinterlace=advanced", this may meet your requirement.

[AmshTemp]

Unfortunately the deinterlace=advanced produces the same result as deinterlace=bob .

Perhaps my wording wasn't precise enough to point out the problem. So I will try to do better with examples.

Yadiff (with Bob) takes every "field" in 50i and converts it to a frame in 50p, which produces the smoothness you would expect from such a conversion.

For vpp_qsv, however, it seems that vpp_qsv converts the 50i source to 25p and then just doubles the framerate to 50p, which results in a non-smooth 50p

NOTE: I attached two videos demonstrating the output difference between Yadiff and vpp_qsv

[wenbin,chen]

I tried it on linux with a similar command line:

ffmpeg -hwaccel vaapi -hwaccel_output_format vaapi -i 50i_sample.m2v -c:v h264_qsv -vf "hwmap=derive_device=qsv,vpp_qsv=rate=field:deinterlace=advanced" -y output.mp4

And I get smooth output. I attach it as well. I going to test it on windows.

[wenbin,chen]

Sorry, I tried on windows, but I still cannot reproduce the issue. Almost all Intel platform support deinterlace so I don't think it is hardware's problem. I am using the latest ffmpeg, and the windows driver is "31.0.101.4824". You can update them and try again. I cannot debug on your environment so I don't know what causes the issue.

[AmshTemp]

My processor is sandy bridge (very old) do you think this might be the problem?

[AmshTemp]

I tested it on another relatively modern processor. Indeed my processor's integrated IGP HD4000 is the source of the problem.

The newer processor didn't have this issue.