Several VAAPI/deinterlacing issues.

Gravarty

I've been using TVHeadend+DVB-S(2) SAT-IP for one year now, and there are some things I wonder could be implemented or fixed. One is adding a toggle or some kind of detection to bypass deinterlacing on progressive channels. 1080i HD channels are deinterlaced just fine, but there are also some 720p progressive channels that are still being deinterlaced, which results in slow-motion playback. Doing deinterlacing on my Fire TV or Android TV stick is impossible because it is simply too weak, so I am using VAAPI to deinterlace and compress the video a bit.

Another problem, which might be a German-only thing, is that all free-to-air private channels are broadcast in 576i, but uses a flag to tell the receiver to stretch the image. The issue occurs when a channel switches from 16:9 to 4:3 and vice versa, which causes the video to freeze and starts to flicker.

I tried experimenting with ffmpeg spawn, but unfortunately this is not supported in Kodi.

ukn_unknown

if I understand right, you want to separate deinterlace checkbox into a combobox with 3 options:

disabled
enabled
enabled (except progressive)
Can you confirm this is what you want?

Gravarty

Yes, a detection to avoid deinterlacing channels that are already airing in progressive.

ukn_unknown

I investigated a little and I think what you asked is possible, if you use software decoding. For testing purpose can you confirm it is fixing your problem. Change that settings to Enable. Note you have to disable Hardware acceleration (in order to use software deinterlace).

ukn_unknown

Upon further reviewing I can tell you that even hardware accelerated deinterlace (vaapi_deinterlace) has this feature (to skip progressive videos if you enable Deinterlace fields only. There is a catch here: if you have Intel CPU this is available now for more than 2 years, if you have AMD this might not be implemented (or maybe was implemented very recently).
Based on the info above, I think we answered your request and I don't plan to change anything in tvheadend. Let me know if you disagree.

Gravarty

Thanks for looking further into this. I already had this setting enabled from the beginning. I now recompiled TVheadend from the latest sources and the issue is somewhat fixed in Kodi, but as soon as I go back to the channel list, it's desynced again and video playback is sped up, like 2x speed (only on progressive channels). This happens on all devices running Kodi, even on my somewhat recent PC (RTX 3060 Ti/12th Gen i5).

This issue doesn’t happen with M3U playback in VLC, so maybe this is really just a Kodi-only issue.

ukn_unknown

Gravarty
I wander if the channels that are progressive, are not tagged properly.
Can you confirm if this behavior is identical when Hardware acceleration check box is On and Off? On will use vaapi hw deinterlace filter and when is Off will use yadif filter. We can try to add in front of yadif (only for software decoding) the filter idet. I don't know if will help of not ... for your case. But this is the best I could come up with 🙁 .