VHS chroma banding troubles

[LeoH]

Hi there,

Wondering if any kind soul can offer advice on this one? I've got a multi-generational PAL VHS tape that I'm trying to encode for DVD - I'm using a "cocktail" of denoisers, and I've cut down the grain and other VHS crap significantly. BUT one thing I can't seem to figure out is this:

http://s90519770.onlinehome.us/test.png
(these annoying horizontal chroma bands that flicker randomly from frame to frame)

Nothing I've tried has had any effect on this. Here's a short clip:

Clip (http://s90519770.onlinehome.us/testclip.avi) (12MB)

Does anyone have any idea for something I could try? Thanks!

~Leo :)

[scharfis_brain]

this clip already has been filtered.

please provide the unprocessed capture without any filtering applied.
(it looks like it is deinterlaced, noise-filtered [heavy smoothed] and deshaked...)

I think, with some special kind of brute force-filtering one could get an acceptable level of quality.

[LeoH]

Thanks for the reply scharfis_brain, OK I've replaced the clip with the unprocessed capture. (The processed clip was deinterlaced and smoothed, but not deshaked.) You can see it's pretty terrible quality! I don't believe in miracles, so I'm just wondering if anything can be done?

Thanks for any input!

~Leo :)

[Wilbert]

Are you using an ATI device?

[LeoH]

Wilbert, no I used a Canopus ADVC-100 to capture the tape. I've used this setup for other tapes without this problem, so I think it must be specific to this tape.

~Leo

[scharfis_brain]

to sort out possible problems with the capping device:

is the color-banding also visible on the TV?

btw.: I have some success filtering the the video, but I need a sample with much more movement in it.
could you up such a sample?

(I had never ever such bad tapes to work on...)

EDIT: here the first attempt to denoise this video:
http://home.arcor.de/scharfis_brain/samples/leoh-den1.avi
I've left it interlaced, so you do not loose the smooth movements!

(I'll post the script later, it is currently more than ultra-crappy!)

[LeoH]

So you like my extremely crappy video?? haha, maybe it makes a good training tool? ;)

The color banding seems to be visible on my TV as well - so i think it is on the tape... :(

Here I've uploaded another clip with more motion in it:

Clip2 (http://s90519770.onlinehome.us/testclip2.avi) (47MB)

Let me know if that is good enough for motion.

Your denoising looks very good to me! I'd be very curious to see your script for it!

Thanks again for your help.

~Leo :)

[scharfis_brain]

loadplugin("D:\x\depan.dll")

avisource("testclip2.avi")
assumetff()

# doubling the framerate
bob()
converttoyv12()

# compensate pans to avoid motion smearing
data=last.greyscale().depanestimate(pixaspect=1.094)
converttoyuy2()
# compensation radius
r=2

last.depaninterleave(data,prev=r,next=r)

# brute force-chroma smoothing over five fields
temporalsoften(r,0,255)

# luma denoising.
# use your favourite denoiser here:
temporalsoften(1,15,0)

# select the 'original' frames
selectevery(1+(2*r),r)

#reinterlace the video
assumetff()
converttoyuy2()
separatefields().selectevery(4,0,3).weave()



this is the script I am using.
it brute-blurs the chroma over 2*r+1 fields.
for temporalsoften(1,15,0) you may insert any other denoiser, you like to.