Is there a way to dither or reduce banding?

[Zap250]

I'm having a problem with a video I'm encoding from an HDTV source. The original 1080i vob file has some major banding problems but it's mostly covered up by grain. There are no fast-motion scenes, but the lighting is somewhat poor.

Here's a sample of an area with some bad banding, taken from the encoded video:
http://img245.imageshack.us/img245/2146/vlcsnap1430231ip0.png
(The same frame from the original video looks about the same, but when playing the encoded video it looks much worse because when in motion it shows up as bands instead of blocks)

I've tried encoding to xvid and it looks about the same as the original, and again the grain covers up the banding. In my x264 encode the banding is very evident as the grain has been removed. I'm using a very minimal avs script btw. Now if there is a way to dither the banding in the background without sacrificing detail in the subject I think it would be barely noticeable.

I've searched all over the forum but haven't found a solution. It seems others who have had this problem have either resorted to using xvid, or ended up using smoothing filters that destroy detail -- neither of which I want to do.

[Blue_MiSfit]

No fast P-skip is a good option.. try chosing a CQM, and reducing the settings of the deblocking filter to preserve more details.

It's tough... H.264 acts as a de-noiser to a certain extent. ASP is better sometimes, especially for noisy stuff that would have lots of banding otherwise.

You can also use GradFun on playback, which will dither out banding nicely.

~MiSfit

[Zap250]

Thanks for the advice. I always have "no fast p-skip" checked, and I can't rely on playback filters such as gradfun - I want to be able to play it in VLC which I understand doesn't support ffdshow filters. I'm not asking to remove the blocking as I understand that's just not possible in AVC without loss of detail, but if the blocking is dithered or blended it would be much more tolerable. I've tried the eqm_avc_hr CQM in the past but I've stopped using it since it seems to destroy detail.

[R3Z]

Thanks for the advice. I always have "no fast p-skip" checked, and I can't rely on playback filters such as gradfun - I want to be able to play it in VLC which I understand doesn't support ffdshow filters. I'm not asking to remove the blocking as I understand that's just not possible in AVC without loss of detail, but if the blocking is dithered or blended it would be much more tolerable. I've tried the eqm_avc_hr CQM in the past but I've stopped using it since it seems to destroy detail.

I find that Blockbuster(method="dither") works very very well. Also if you dont like sharktooths matrix, try the prestige cqm matrix found here;

Prestige.cqm (http://forum.doom9.org/attachment.php?attachmentid=7278&d=1180682736)

[Zap250]

I tried Blockbuster, and I tried the prestige matrix. Blockbuster seemed to work best, but the improvement was still negligible.

I think I had the gamma set just a little too high on my monitor; I turned it down just a couple notches and it made a big improvement. Not sure how it got out of adjustment, but I should have noticed that. Anyway, I would say everything is ok now.

But next time I run into major blocking problems (now that my monitor is adjusted properly) I have some more solutions I can try. So thanks to both of you for your help.

:thanks: