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Old 30th August 2006, 12:10   #61  |  Link
gatekeeper_007
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...from what I understand that this filter is being made only for viewing and not for processing.

I' searching for a filter that helps with 'banding' when compressing! (in YV12 mostly)...

any advice ?

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Old 30th August 2006, 12:46   #62  |  Link
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Banding is best fought during post processing. Whatever method you'll try to use in preprocessing, it's more than likely that the effects will get lost during the compression, unless you're using a very high bitrate.
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Old 30th August 2006, 12:53   #63  |  Link
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@ Manao: it still helps however. And, most important, this filter doesn't reallly destroy details in picture.

I use this filter for HD content which I transcode to avc. I can't see more banding added compared with filtered but not yet encoded video. Maybe AVC has less chance to create banding, dunno
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Old 30th August 2006, 12:56   #64  |  Link
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yes you're right..,
most of the time I get it when I'm compressing to much,
but sometimes I get banding even when all i/p/b-frames are 2 and 3 quant. with(H263/MPEG)... so I guess in that case it's not about the bitrate... and I try to found out why and how to fix this/if I can .

Thx 4 the reaply
and Keep up the good work
respect
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Old 30th August 2006, 16:52   #65  |  Link
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Quote:
Originally Posted by gatekeeper_007
yes you're right..,
but sometimes I get banding even when all i/p/b-frames are 2 and 3 quant. with(H263/MPEG)... so I guess in that case it's not about the bitrate...
Just cause a frame is a quant 2 or 3 doesn't mean it's high bitrate.
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Old 31st August 2006, 09:57   #66  |  Link
gatekeeper_007
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Quote:
Originally Posted by Hurricane Neddy
Just cause a frame is a quant 2 or 3 doesn't mean it's high bitrate.
yes, I know that with differend settings and/or scripts you can mess a lot with the compressability of a clip, and you can get frames 2/3 quant which will need a low bitrate...
(but they wont look much like 2/3 quant)

...but when you're compressing at a 640x480 res. without using a denoiser, - costum matrix, or settings like 'lumi masking', trelis ... and others that can be helpfull with the compressabilyty , -without Bvop's or with but never higer than 1/1.0/1.0... etc. the bitate can't be so low...
to go higher with the bitate it wouldn't be smart as it won't be much of a compression anymore...
after all this way the clip is almost perfect:
-no blocks
-no artifacts
-no mosquito noise
-the only thing is the 'banding' I get (hoping to fix that to)

anyway...
I'm really sorry to post my question here, I didn't meen to mess much with the thread.
4 the replys
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Old 8th September 2006, 04:36   #67  |  Link
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great filter

I just wanted to say thanks, this solved a problem for me!
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Old 18th September 2006, 21:35   #68  |  Link
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Originally Posted by foxyshadis View Post
Really, YV16/YV24 is the only way to truly remove visible banding in encodes. (If lavc could decode to YV24 and convert straight to RGB that would be awesome.)
That's not possible in inter-predicted codecs. No matter whether you meant higher colordepth or less chroma subsampling ("YV24" is ambiguous), any attempt to do that within the decoder will introduce encoder/decoder desync, thus adding way more artifacts than you save in reduced banding. OK, so you could decode B-frames with higher colordepth than the format specified, but that wouldn't really help if they're predicted from a banded P-frame.
The only way it will work is if the encoder and bitstream also use the higher colordepth, i.e. h264 hp.
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Old 5th February 2008, 21:47   #69  |  Link
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Two examples of gradfun2db in action (preprocessing, but it has a very nice effect when banding is this visible, even after encoding):

http://xs124.xs.to/xs124/08062/gradfun2db558.png

(this image is actually after a few scene changes from the last one)
http://xs124.xs.to/xs124/08062/gradfun2db2838.png
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Old 6th February 2008, 02:32   #70  |  Link
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Here is a question, how do you deal with the color residue leftover after a debanding filter has been applied?

Sure, the hard edges have been removed, but often times there is still a soft band of color lingering in its wake.

This only happens on some sources I know, mainly any with strong banding, but I am wondering how to deal with those select few.
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Old 6th February 2008, 05:27   #71  |  Link
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Raise the strength, then add noise. That's about it.
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Old 6th February 2008, 06:09   #72  |  Link
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So, say that I have gradfundb(1.4) and it removes the hardedges, but it leaves the color.

If I raise it to (1.5) or (1.6) and use AddGrain(), then that should take care of it? Wouldn't that hurt compressibility? Or is it negligible?
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Old 6th February 2008, 08:57   #73  |  Link
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Well, you might want to apply separately to luma and chroma.
l = gradfundb(1.4)
c = gradfundb(2.2).addgrainc(0.0,1.0)
mt_merge(l,c,c,y=2,chroma="copy second")
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Old 6th February 2008, 09:14   #74  |  Link
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Cool. Thanks for that.

I was under the assumption that banding was a chroma artifact only. I guess to assume makes an Ass out of U and Me.

I will give that code a try and see how it goes.
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Old 8th February 2008, 17:04   #75  |  Link
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although i havent tried it, but this filter would work great to help hide decoding artifacts from Divx videos and as such to provide a much cleaner source which doesnt appear to have much compression in the video file, like MPEG 2 and lossless (to be prefered, as there isnt any).
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Old 24th March 2008, 04:34   #76  |  Link
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Hello. I am trying to figure out what to do to get rid of banding (actually almost everybody in this thread)..

So I have this after encoding (Banding is mainly visible in the sky) :

What do you think I should try?

Last edited by vaioslar; 24th March 2008 at 04:45.
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Old 24th March 2008, 07:22   #77  |  Link
rfmmars
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I simply can't see it, is your display the problem?

Richard
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Old 24th March 2008, 16:29   #78  |  Link
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Originally Posted by rfmmars View Post
I simply can't see it, is your display the problem?

Richard
It is like some pixels are darker than others and these ones seem to be moving...i can upload a video sample..
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Old 24th March 2008, 18:15   #79  |  Link
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Yes a clip that would help...........looking at your samples I see no banding that why I thought you may not have your monitor set at 32 bit resolution. Does this show on a DVD?

Richard
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Old 24th March 2008, 18:31   #80  |  Link
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Yes a clip that would help...........looking at your samples I see no banding that why I thought you may not have your monitor set at 32 bit resolution. Does this show on a DVD?

Richard
I will now upload a sample. It is not actually a DVD. It is a BluRay

--->http://rapidshare.de/files/38916572/...muxed.rar.html

Last edited by vaioslar; 24th March 2008 at 18:34.
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