Banding With Avisynth

[PDB]

I wanted to pick some brains here. Anyone get banding from avisynth?

I ask because I'm getting some banding in some of my upscale work. I'm wondering what is causing it. Some of the DVD's have it built in already. Problems of the 8-bit world but upscaling seems to make it worse. Could that be a function of working in the 8-bit area or some color space conversions?

I've tried some of the avi plugin de-banding solutions and they all look sub par and destroy picture details.

[Colek]

Mostly because of digital sharpening used for the said master that wasn't implemented good. If you want to sharpen out your video, I recommend using LSFmod but it's very performance heavy.

[Chewtobacca]

Problems of the 8-bit world but upscaling seems to make it worse. Could that be a function of working in the 8-bit area or some color space conversions?

Yes. If you are converting to RGB and back and then upscaling, banding would probably be more noticeable.  I don't know what your workflow is, but you I suppose you might upscale and then apply color correction (if that's what you are doing).

[PDB]

Thanks guys for the help

Mostly because of digital sharpening used for the said master that wasn't implemented good. If you want to sharpen out your video, I recommend using LSFmod but it's very performance heavy.

I just tried turning off all sharpening and its still there sadly. Its on the DVD and I guess the upscaling seems to make it worse

Problems of the 8-bit world but upscaling seems to make it worse. Could that be a function of working in the 8-bit area or some color space conversions?

Yes. If you are converting to RGB and back and then upscaling, banding would probably be more noticeable.  I don't know what your workflow is, but you I suppose you might upscale and then apply color correction (if that's what you are doing).

The workflow I have right now is:

1. keep it in yv12 (rec601) in avisynth (since the plugins mostly require that colospace)
2. upscale and process the script in vdub, convert to RGB colorspace (also rec709)
3. output in lags RGB
4. pull into premiere for editing and color correction

Is there a way to supersample/up-sample in avisynth that might help?

[Chewtobacca]

AviSynth is not exactly high bit-depth friendly.  Have a look here.  I've never experimented with this though.

[PDB]

Thanks Chew, that was my understanding. I do want to look at vapoursynth. Been meaning to for a while