Question / Help Deinterlacing with Yadif 2x on Linux

[Daren_K]

Hi,

I've not managed to get a proper 480p60 output with the Yadif 2x deinterlace option from a proper 480i60 source that has 60 separate fields per second (smooth as 60 fps on CRT and TV).
I'm instead getting either 30 fps or jitter as if the field order is wrong (tested both top and bottom field first). Sometimes it periodically switches between jitter and 30 fps.
Yadif (1x) works stable for deinterlacing to 480p30.

This happens with two different capture cards that forward interlaced footage without doing deinterlacing themselves:

• Blackmagic Design Intensity Pro - OBS Blackmagic Device API - Both HDMI and Analog cables tested
• A chinese USB grabber - V4L2 API - lsusb output "Bus 001 Device 006: ID 1b71:3002 Fushicai USBTV007 Video Grabber [EasyCAP]"

Combing visible when deinterlacing is not activated, both with the same issues described above with Yadif 2x.Tried off a complete fresh .config/obs-studio with no scaling filters or additional effects on the source.

I can record interlaced footage with the Blackmagic Software (Media Express) and deinterlace that footage offline with "ffmpeg -vf yadif=1" for smooth deinterlaced 480p60.

obs-studio 25.0.4 on Arch Linux without special build options:

Explore groups · GitLab

GitLab Enterprise Edition

git.archlinux.org

I talked to a Windows OBS user that doesn't have any such issues deinterlacing e.g. 1080i60 to 1080p60 using Yadif 2x.
Might this functionality be broken on Linux for some reason?

 

[evf]

I am having the same issue with the BlackMagic Intensity Pro 4K. It seems it doesn't deinterlace properly with "Yadif 2X", where both the top or bottom field first options make the picture look very jittery. I only see this problem with the yadif 2x on the Blackmagic though, as I've tried other deinterlace options and other (cheap) capture cards without any problems.