[HELP] Unstable Umatic capture

[Miranda]

Is there anything I can do to fix this? Its from a 1983 PAL Umatic master.

sample clip

[Selur]

Looks like extrem skew error.
Aside from writing a custom script similar to ReduceFlicker, maybe applying ReduceFlicker 10+ times and Small_Deflicker additionally helps,... (not really, see attachment)
Hybrid has no build-in filter, really tailored for this.
Maybe someone over at https://forum.videohelp.com/forums/41-Restoration or https://www.digitalfaq.com/forum/video-restore/ can suggest a tool for this.

Cu Selur

[Selur]

LOL, I think I found something, try:

# removing flickering using ReduceFlicker
clip = core.rdfl.ReduceFlicker(clip=clip, strength=3, aggressive=1)
# removing grain using SMDegrain
clip = smdegrain.SMDegrain(input=clip, interlaced=False, dct=1)

the dct=1 in SMDegrain is what really helps. (but, yes it's slow)

attached an encode with:

# removing flickering using ReduceFlicker
clip = core.rdfl.ReduceFlicker(clip=clip, strength=3, aggressive=1)
# removing grain using SMDegrain
clip = havsfunc.SMDegrain(input=clip, tr=4, interlaced=False, dct=1)
# removing grain using SMDegrain
clip = havsfunc.SMDegrain(input=clip, tr=4, interlaced=False, dct=1)

=> so with some tinkering this might really be somewhat fixable.

Cu Selur

[Miranda]

Thanks, will this also work on an interlaced upscale?

[Selur]

Probably, but a lot slower,... dct=1 will slow stuff down a lot when the resolution increases,...
This is something that should be fixed during capturing the further you go down the line the harder it will be to fix,...

[i4004]

on a hardware side of things, tbc is made to fix stuff like that....if you have one at hand....

[Miranda]

How do I add SMDegrain twice?

[Selur]

You use 'Filter Queue' instead of 'Filter Order' (read: [INFO] About Vapoursynth Filter Order/Queue), then go to SMDeGrain and add it.
With 'Filter Queue' enabled there are '+'and '-' controls to the right of each filter. (will probably move these to the front in the next release)


Cu Selur

[zspeciman]

I recall a model called vhs-deshaker, it addresses horizontal shakes  It analyzes the pure black at the left and right borders of VHS video frames it tries to align the frame itself.
Perhaps worth looking at.  

https://github.com/rsnitsch/vhs-deshaker...me-ov-file

[Miranda]

Looks interesting, any plans to add it to Hybrid I wonder?