Trying to fix badly interlaced video in Avisynth

[ENunn]

at the tv station i work at we have a setup for transferring our beta tapes. the issue is that the encoder that we have SUUUCKS. 10mbps mpeg2, anamorphic widescreen 480i with pillarboxing, and the fields are screwed. the raw video when imported in premiere is jagged and jumpy. i know you gotta do what you gotta do if you're in a time crunch but i wanted to see if this could be fixed in software.


i was able to fix this in vapoursynth with some help, but i'm much more familiar with avisynth. plus trimming both video and audio at the same time is much easier for me. is there a way to fix this in avisynth? sample attached.

[Selur]

QTGMC+SpotLess+Small_Deflicker should work, but you can probably do whatever you did in Vapoursynth,...

Cu Selur

[ENunn]

QTGMC+SpotLess+Small_Deflicker should work, but you can probably do whatever you did in Vapoursynth,...

Cu Selur

can't seem to get it to look as good as the vapoursynth script i used. it sucks because trimming is a LOT easier in avisynth :/

[Selur]

What does your Vapoursynth script look like?

[Alwyn]

@ENunn, difficult to experiment without knowing what you achieved with Vapoursynth. Can you post an example of that.

Re trimming, can't you do that in Premiere?

MPEG 2 in AVI is rather odd, I would have thought. And the frame size is normally for PAL, not 29.97/NTSC.

Surely a standard modern USB digitiser would do a far better job than the current gear the station is using. That sample really does look bad. The video itself looks pretty good, just badly captured.

[Selur]

@Alwyn: Thanks, fixed the link of Small_DeFlicker to https://forum.doom9.org/showthread.php?p=1812060#post1812060

[Alwyn]

Here's my attempt with AVISynth.

v=LWLibavVideoSource("H:\Videohelp\Enunn\Monday 10PM B Week Cap 2 clip2.avi")
a=LWlibavAudioSource("H:\Videohelp\Enunn\Monday 10PM B Week Cap 2 clip2.avi")
AudioDub(v,a)
ConvertToYV16()
Spline16Resize(400,300)
santiagmod(3,3)
QTGMC(inputtype=2)
converttoyv12()
lsfmod(strength=100,Smode = 3)
Spline64Resize(720,576)
dehalo_alpha()

[lollo]

Alwin, I did not check the source neither the outcomes, but a dehaloing after a sharpening makes little sense in principle. Are you sure of the sequence of the operations in your script?

[Selur]

DeHalo after sharpening makes sense if you want to remove some artifacts introduced by the sharpening.

[lollo]

Which makes no sense. Better to play on the sharpening parameters than, because dehaloing is a (global) destruptive operation

But maybe there is a good reason for this source, I did not check it...

[Selur]

DeHalo should be mainly around edges and not 'global',...

[lollo]

Not really

[Alwyn]

@Lollo, since LSFMod creates halos, I thought Dehalo should come after.

[Selur]

I use DeHalo filters (mostly YAHR) quite often to remove halos caused by sharpen filters. ¯\_(ツ)_/¯

[jagabo]

The fields are stored in the wrong spacial order. Ie, the lines of the top field are stored below the lines of the bottom field.

LWLibavVideoSource("Monday 10PM B Week Cap 2 clip2.avi") 
ConvertToYV24(interlaced=true) # to allow cropping one line off the top and adding one at the bottom
Crop(0,1,-0,-0).AddBorders(0,0,0,1)
SwapFields()
QTGMC()

You can then fix other issues...

[Sharc]

The fields are stored in the wrong spacial order. Ie, the lines of the top field are stored below the lines of the bottom field.

Wow! Good catch!

[jagabo]

The fields are stored in the wrong spacial order. Ie, the lines of the top field are stored below the lines of the bottom field.

Wow! Good catch!

I've dealt with this many times before. There was an old Matrox capture device that stored video that way.

[ENunn]

What does your Vapoursynth script look like?

@ENunn, difficult to experiment without knowing what you achieved with Vapoursynth. Can you post an example of that.

someone cobbled this up in vapoursynth and sent it to me.

import vssource
import vstools
import vsdeinterlace
import vskernels
import ctypes
import sys
import os
import adjust

vs, core = vstools.vs, vstools.core


clip = vssource.BestSource.source(r"Monday 10PM B Week Cap 2 clip.mxf").std.SetFieldBased(2)

luma = vstools.get_y(clip)

fields = luma.std.SeparateFields()
fixed_top = vskernels.Point().scale(fields[::2], shift=(1, 0))
woven = vsdeinterlace.reweave(fixed_top, fields[1::2], True).std.SetFieldBased(1)
fixed = vstools.join(woven, clip).std.CopyFrameProps(clip, "_ChromaLocation")

qtgmc = vsdeinterlace.QTempGaussMC(fixed)
qtgmc.basic(noise_restore=0.5)
qtgmc.source_match(tr=2, mode=qtgmc.SourceMatchMode.TWICE_REFINED)
qtgmc.lossless(mode=qtgmc.LosslessMode.PRESHARPEN)
qtgmc.final(tr=2, noise_restore=0.25)
deinterlaced = qtgmc.deinterlace()

vstools.set_output(clip)
vstools.set_output(fixed)
vstools.set_output(deinterlaced)

Re trimming, can't you do that in Premiere?

yeah i could. i have to encode the whole thing out but i definitely could.

MPEG 2 in AVI is rather odd, I would have thought. And the frame size is normally for PAL, not 29.97/NTSC.

it was originally an mxf file, but videohelp doesn't support attaching mxf files for some reason so i rewrapped it into an avi file.

Surely a standard modern USB digitiser would do a far better job than the current gear the station is using. That sample really does look bad. The video itself looks pretty good, just badly captured.

right?? even my jank setup at home looks better than this! whoever set this up should be fired lmao

The fields are stored in the wrong spacial order. Ie, the lines of the top field are stored below the lines of the bottom field.

LWLibavVideoSource("Monday 10PM B Week Cap 2 clip2.avi") 
ConvertToYV24(interlaced=true) # to allow cropping one line off the top and adding one at the bottom
Crop(0,1,-0,-0).AddBorders(0,0,0,1)
SwapFields()
QTGMC()

You can then fix other issues...

thanks!! that helped a lot!!

[Alwyn]

yeah i could. i have to encode the whole thing out but i definitely could.

Just open the AVS in VDub2 and trim there. Depends what you want to do with it, of course.