help to deinterlace blended dvd video

[spiritgumm]

Trying to convert dvd video (source unknown) to avi or mp4. Seems to be interlaced with blends. Tried deinterlacing with srestore(23.976), but there's slight judder (an extra frame every couple seconds). Also tried removing blends by deinterlacing with srestore(29.97) and Tdecimate, but same judder. Just TFM/Tdecimate wont remove the blends.

[jagabo]

frate=23.5 looks about right.

[spiritgumm]

My god, how did you figure that out? I jumped thru the rest of the video with that, seems to play fine.

Well anyway, needless to say, many thanks!! Would still love to know how you figured it since I wasted time on it, and you got it pretty quickly.

[theewizard]

probably experience, he looked at it , and that 'feeling' what he was viewing should be 23.5

like a race car driver listening to an engine

[spiritgumm]

Probably trial and error since this is a non-standard frame rate. Amateur transfers of silent films are often transferred at non-standard speeds, so I tried a few different ones here, but got discouraged. I was just surprised he hit on it so quickly.

[jagabo]

I counted the number of repeat frames over a period of video then calculated what frame rate should be. For example, if you have 10 repeats over 100 frames you need to reduce the rate by 10 percent. But the repeats in this video aren't at fixed intervals so the method may be a little off. I came up with 23.35. When I tried that rate it was too low -- it removed a few unique frames. So I guessed at a higher rate and picked 23.5. I was going to use successive approximations but 23.5 worked.

[spiritgumm]

Do you mean before or after decimation? I had difficulty trying to count repeat frames before decimation because of the irregular intervals, which is why I only tried to treat the errant dupes after decimation. I got an extra frame after 52 frames, then an extra after 45 frames, etc. So I guess that would be aprox. 98% which would yield approx. 23.5, but I would never have used that equation to figure out the correct FPS.
Anyway, bravo for sticking thru with it, jagabo! They dont pay you enough to do this stuff.

[jagabo]

I counted dups after the decimation to 25 fps by SRrestore. I counted something like 13 dups in 225 frames -- I forget the exact numbers. But using those numbers:

25 fps * (225-13) / 225 = 23.55 fps