vertical jitter reduction filters?

[lordsmurf]

Aside from deshaker (which is not very good at jitter removal from my trials), what are our options?

The TBC and VCR can reduce these.
Sometimes simple deinterlacing can help reduce it (although that introduces new artifacts that must be countered).

But what else can we do?

[guns1inger]

MSU have a field shift plugin for Avisynth : http://compression.ru/video/old_film_recover/field_shift_en.html

The difference between this and other field shifters or field reversers is that it appears to do analysis and adjust it's behaviour on the fly.

Not sure if it is exactly what you are looking for though.

[lordsmurf]

I'm a GUI user. What would be the proper avisynth script for loading from either HuffYUV or MPEG-2 source, and then running this filter on it?

Should I pre-crop the video, to remove overscan noise?

The jitter I refer to is VHS instability, the jitter is usually a few field lines, not just 1 line. Would this still work?

An option I've had success with in the past was a hard(simple) deinterlace of footage, followed by a session in Steadyhand. It fixed many problems, but added some, too. The final video was built from multiple de-jitter methods, taking best part from each. But it's so much work. 20 minutes of footage takes about 20 hours of user work (excluding encode times, which can run into days/weeks of time)

The new problems were caused by non-vertical adjustments, because the "steady" or "shake" softwares always tend to look at horizontals, too. I'm hoping for something that can address purely vertical flaws, be it interlaced or progressive (or deinterlaced) footage.

[guns1inger]

They actually take you through a basic script on the page I posted, including an explanation of each line. You only need the last ConvertRGB24() line if you are going to encode with the old Tmpgenc, which required RGB input, or if you are going to do further work in virtualdub.

You can crop using the Crop() statement

If you prefer a GUI playground, use AvsP to generate your scripts. It has a preview function, and a pretty good coding environment with hints and auto-completes for most Avisynth functions.

Ironically, this is one of the few purely Avisynth filters they have. Most are written for Vdub, with AVS supported added afterwards through the LoadVirtualdubFilter() statement

[lordsmurf]

I'd generally de-jitter, export to new AVI, then work on AVI more either in VirtualDub or the editor. The videos tend to be so degraded that a few uncompressed re-encodes won't cause any quality loss, especially not compared against the improvements being made at each step.

I don't think what you've suggested is going to work, but I plan to try it anyway -- it's the most hopeful so far. I plan to try out vReveal too (again), but I doubt it will do much for the high-speed sync jitters. There's another Premiere plugin, on other computer, have trial of it, too.

I don't think anything exists.

Reason for post was to learn any and all possible methods.

Thanks for the help so far.

[guns1inger]

I suspect this is basically for screwed field order, however the adaptive nature suggests something more. Be interested in your results.

[lordsmurf]

Mercalli Expert is the name of the Premiere plugin.

Lots of people online consider it crap from reviews I've read.
But if you know me, you know my thoughts on bad online user reviews.

[2Bdecided]

The problem I found with deshaker is that it always tries to follow the unwanted movement a little. Other than that, it should work with appropriate parameters.

The "comparable" AVIsynth filter (actually completely different, but designed for the same job!) is depan. It's easy enough to make it correct vertical movement only.

I don't know either software well enough to make it fix single errant frames, but leave everything else untouched. Might not be too much of a problem in practice.

Cheers,
David.

[jagabo]

Try AviSynth's Stab()

[2Bdecided]

I've used that. It's "just" a depan preset. It's great for small errors.

It has the same inherent flaws as other options, but because it's hard wired to only correct small errors, it can also only make small mistakes.

Cheers,
David.

[jagabo]

It's designed for projector bounce so it should work well with Smurf's jitter problem -- if I understand what he means by that.

[poisondeathray]

If I'm not mistaken, you can limit depan to one axis by changing depanestimate's dxmax or dymax to zero. I think changing dxmax=0 would make depan only affect y-axis shifts.

[lordsmurf]

I see Depan at http://avisynth.org.ru/depan/depan.html

@poison (or anybody, jagabo)
What would be the proper script for making dxmax=0, etc. ?
I see some script examples at the above URL, but they don't really make a lot of sense to me. As usual, it assumes prior experience with Avisynth.

VHS jitter is very fast, generally lasts only 1-2 frames, and can move from just 1 line to 3-4 lines. That's why simple interlace swapper filters don't really work.

I would want to set the filter to ONLY work on those sudden vertical movements, not on slower movements, like pans or even camera shakes (which still move much slow than jitter). Is there a way to set minimum speed for what is consider bad movement?

[poisondeathray]

I did a quick test and the dxmax=0 does limit it to y-axis jitters.

I only know the basics lordsmurf - you'll have to play with the values to get better results. e.g. to change the sensitivity like vibration cutoff for the frequency in hertz to match your clip's sudden movements. It might look something like this:

LoadPlugin("PATH\DePan.dll")
LoadPlugin("PATH\DePanEstimate.dll")

AVISource("shaky.avi")
mdata = DePanEstimate(dxmax=0)
DePanStabilize(data=mdata, cutoff=0.5, damping=0.5, mirror=15, blur=30, method=1)

In this example, I set to mirror edges - it shouldn't matter if your jitter is only like 1 or 2 pixel amplitude.

Here are some examples (stacked a/b compare), with normal depanstabilize (no dxmax limit), and one with dxmax=0. The test clip has jitters in x and y.

jitters.rar

Another option , if you have After Effects, is to motion track and apply stabilization data to y-axis only

[lordsmurf]

I have After Effects in CS3 and CS4, but I've never used it.

Thanks for the assist on the depan. I'm to going to give that a try on a test video.