Anything I can do about lots of double frames?

[Ygramul]

I have a rip of an old movie and it's almost unwatchable because every third frame is duplicated (1-2-3-3, 4-5-6-6, 7-8-9-9 etc.). To make things more complicated, it's inconsistent and only affects SOME parts of the video.

Here's a sample: https://pixeldrain.com/u/5xz1qMrk

[Selur]

You could:
a. use SelectEvery in Avisynth or Vapoursynth if the pattern is fixed.
b. you could use TDecimate or sRestore if the pattern isn't fixed
The downside to these approaches is that, for your 24000/1001 source, you end up with a 18000/1001 output fps.
c. interpolate the duplicate frames (i.e. using FillDrops)

Cu Selur

[Ygramul]

You could:
a. use SelectEvery in Avisynth or Vapoursynth if the pattern is fixed.
b. you could use TDecimate or sRestore if the pattern isn't fixed
The downside to these approaches is that, for your 24000/1001 source, you end up with a 18000/1001 output fps.
c. interpolate the duplicate frames (i.e. using FillDrops)

Cu Selur

Thanks, I'll give those a try. It definitely isn't consistent. The first couple of minutes are like the sample I posted, but somehow the middle is fine.

[Hunk91]

I'm not an expert but here is what you can do with avisynth :
#1 opening the video file with FFMpegSource2 (this should delete the doubles)
#2 regarding the number of frames per second I would try a frame interpolation filter like interframe to match 24 fps if the source is film, or 25 fps if the source is Pal, 23.976 or 29.90 fps if the source is NTSC.

I fear this may cause audio sync issues but not sure.

Best regards

[jagabo]

The first of the duplicates is a substitute for missing frame -- a duplicate of the next frame was used instead of the missing frame. Simply removing one of the duplicates will give jerky motion as there's still a missing frame. Using a motion interpolation frame rate doubling you can restore the missing frames. Something like this:

LWLibavVideoSource("DoubleFrames.mp4") 
Trim(1,0) # just to make the starting point a little easier
InterFrame(FrameDouble=true, cores=2) # double the frame rate by adding a motion interpolated frame between each frame
SelectEvery(8, 0,2,4,5) # pick out the ones we want
# output is 23.976 fps with the dupes removed and the missing frames "restored"

A better frame rate doubler will give better results. The difference may not be so noticeable in talking head shots but it will be very noticeable in panning shots or other shots with smooth motion.

Attached is the above clip using RIFE instead of InterFrame.

[Ygramul]

The first of the duplicates is a substitute for missing frame -- a duplicate of the next frame was used instead of the missing frame. Simply removing one of the duplicates will give jerky motion as there's still a missing frame. Using a motion interpolation frame rate doubling you can restore the missing frames. Something like this:

LWLibavVideoSource("DoubleFrames.mp4") 
Trim(1,0) # just to make the starting point a little easier
InterFrame(FrameDouble=true, cores=2) # double the frame rate by adding a motion interpolated frame between each frame
SelectEvery(8, 0,2,4,5) # pick out the ones we want
# output is 23.976 fps with the dupes removed and the missing frames "restored"

A better frame rate doubler will give better results. The difference may not be so noticeable in talking head shots but it will be very noticeable in panning shots or other shots with smooth motion.

Attached is the above clip using RIFE instead of InterFrame.

This looks pretty good! I've never used Avisynth, though. I should read some tutorials because I don't even know how to use the commands you posted.