Smoother 24fps @ 60hz playback

My stupid plasma claims to support 24fps, but judders with it (probably does 3:2 internally).

When playing 24fps @ 60Hz, usually 3:2 is applied like this:

A, A, A, B, B, C, C, C, D, D, E, E, E, F, F

This approach produces very visible motion judder. Is there any chance to implement a simple frame blending algo like the following to “upsample” 24fps to 60fps?

A, A, (A+B)/2, B, B, (B+C)/2, C, C, (C+D)/2, D, D, (D+E)/2, E, E, (E+F)/2, F, F

Just to make sure there are no misunderstandings: This is not motion interpolation, instead it’s very simple frame blending. This is (more or less) similar to what madVR and mpv do when activating “smooth motion”. It very nicely removes the 3:2 pulldown judder, resulting in playback which is just as smooth as true native 24fps @ 24Hz playback. Of course it’s not a perfect solution, it does introduce a small amount of blur and ghosting, but these problems are almost invisible, and the motion smoothness improvement is dramatic.

(Ideally, the frame blending should be done in linear light, but I expect that to require too high GPU power, so simple blending in gamma light would be more than fine.)

If there’s any chance to add support for something like this, I’d be quite happy. If this gets added, we might need an additional option like “my TV sucks at 24fps playback”, to make sure OSMC/Kodi don’t ever activate native 24Hz output. Instead Kodi should auto switch to 60Hz (if auto refresh rate adjustment is enabled) and activate this smooth motion algorithm.

Edit: FernetMenta already implemented something similar for Kodi, but only for OpenGL, and his approach is probably more complicated than my very simple suggestion above:

Just curious: What brand and model is your plasma?

It’s an old Panasonic TX-50PF10EK. Bought 2nd hand. Used plasmas are insanely cheap atm. Quality is great, overall, except for 24fps motion smoothness.

Mine is a Panasonic TX -P42GTW60 and 24 fps as well as all other modes are absolute fluent, so I wonder what could be the problem. I think you have checked that the frame is really 24 fps when seeing this effects (use the context button on the remote control while the playback).

Your plasma is 5 generations beyond his (60 at the end vs 10). I have a VT50 and it’s fine with 24p, too.

Oh, and I’m pretty sure if he says something is happening a certain way, it is. More of his video tools are used in the BluRay to rip viewing process than pretty much any other (other than maybe MKV Tools).

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Thanks nabsltd :slight_smile:

Yeah, my brother and I recently both bought a used plasma, when we noticed how cheap they were. His is a GW10, I think 1-2 generations newer than mine, and his is perfectly smooth at 24fps playback. Unfortunately mine is not. Mine is great at 50hz and 60hz, but judders to some extent at 24hz.

Over the years I’ve also received quite a lot of reports from madVR users, saying that their displays don’t handle 24fps playback very well, either, and that madVR’s smooth motion frame blending produces smoother/better results for them. Seems that there are still some TVs out there today which don’t handle 24fps as well as they should, although the situation has clearly improved a lot.

In any case, I think having an algo which can improve 24fps @ 60hz playback on the Vero 4K would be pretty awesome. If that’s not possible, I’ll either have to replace the plasma, or replace the Vero 4K. Would be so much easier to keep both…

This same sort of blend works with 25p on a display that doesn’t support it natively. Some 25p works great for me, but Broadchurch was terrible until I did the same frame blending to convert to 30p.