Cannot get rid of banding/blocks in darker scenes.

[SatoriGFX]

Hi there,

I have been doing quite a bit of encoding using both TMPG and CCE. One thing that I have found is that I am unable to get rid of the banding or blocks in darker, low motion scenes. The artifacts show up mostly on things like walls, fog and other slow/non-moving wide areas of a similar color. I have noticed these problems while backing up several DVD's including City Of Lost Children, In The Mood For Love, The Devil's Backbone and so on.

I have experienced this with everything from XVCD's to XSVCD's. I always use a fairly high bitrate (usually at 2750 (video only) CBR if I can). But even with a 352x240 XSVCD's at 2500 CBR or CVD's at 2750 CBR I still get some artifacts.

I have tried a few different filters (convolution3d, temporal smoother and so on...found alot of ideas in the script database thread) with no substantial improvements (and often many negative effects).

This isn't a bitrate issue, I don't think, since most of the rest of these encodes look exceptional.

How can a high action scene with lots of moving objects look so good yet a simple (though darker) scene with few or no moving objects look so bad if I am using CBR? Logic would suggest that the darker/simpler scenes should come out looking, if anything, "better" than the brighter/higher action scenes.

I have searched the forums front to back. Seems most of the posts regarding this issue are all bitrate related. Usually, people are encoding using VBR and need to increase their min. bitrate or their average or "smooth" the video because they are using a lowish average bitrate. Since I am already using a fairly high bitrate and CBR and experience the same problems at CVD and VCD res. using these same bitrates, there must be another explanation.

Any help would be greatly appreciated.

SatoriGFX.

[jorel]

did you try the Sansgrip filters:
fluxmoother, blockbuster and legalclip?
i ever use them with lanczosresize...
result in sharping without blocks.

use the "search" and you find them all here!
it's a good idea test a chapter or litle avi!;)

[SatoriGFX]

Originally posted by jorel
did you try the Sansgrip filters:
fluxmoother, blockbuster and legalclip?
i ever use them with lanczosresize...
result in sharping without blocks.

use the "search" and you find them all here!
it's a good idea test a chapter or litle avi!;)

I have used blockbuster and fluxsmooth but never legalclip. I will try that one out as well.

Thanks.

SatoriGFX.

[SatoriGFX]

jorel,

Well, I tried an encode using the following script:

[AVISYNTH_LanczosResize, Fluxsmooth, Blockbuster, Legalclip]
0=LoadPlugin(!FluxSmooth.dll)
1=LoadPlugin(!Blockbuster.dll)
2=LoadPlugin(!Legalclip.dll)
3=LanczosResize(^TargetWidth,^TargetHeight)
4=FluxSmooth()
5=Blockbuster( method="noise", detail_min=3, detail_max=10, variance=1 )
6=Blockbuster( method="sharpen", detail_min=^detail_min, detail_max=^detail_max, strength=^Strength)
7=Legalclip()
8=AddBorders(0,^BorderTop,0,^BorderBottom)
!FluxSmooth.dll=F:\Creation\DVD2SVCD\Avisynth\plugins\FluxSmooth.dll
!Blockbuster.dll=F:\Creation\DVD2SVCD\Avisynth\plugins\Blockbuster.dll
!Legalclip.dll=F:\Creation\DVD2SVCD\Avisynth\plugins\Legalclip.dll
^detail_min=20
^detail_max=90
^Strength=3

I used 2750 CBR as usual and I still see lots of contour lines. This movie (City Of Lost Children) has lots of darker, foggy, moody scenes. The fog in particular shows the banding/contour lines alot.

I have no idea where to go from here. I have tried so many test encodes with little difference as far as dark scene quality goes.

Thanks for the suggestion anyhow.

SatoriGFX.