MPEG blocking & CNR2

[MattO]

Hello all,

Can someone tell me what is the best filter for getting rid of, or smoothing out, the MPEG blocking which mainly occurs in low bitrate encodes?
I know some people will tell me to test all the available filters myself but I didn't know if anyone else has looked into this before.

On another point ... can anyone help me with CNR2?
Could someone explain the various settings in CNR2 in basic terms (more basic than the readme file), for a stupid person;), and the effect they have on the image.
Does anyone have any good alternative settings other than the default ones?

thanks

MattO

[sh0dan]

Try Convolution3d, SmoothHiQ or TemporalSoften, or combinations of these.

Edit: spelling

[Boulder]

I tried CNR2(v2.2) yesterday and it didn't do anything to the video. I tried the compare script Marc wrote in the thread where he told about the filter but the result is just black, nothing more. Different settings do no good either.

I've found out that Convolution3d is a very good filter for deblocking. I've done several DivX->VCD conversions using that and it works very well. My settings were (0,8,16,8,16,3,0) most of the time, sometimes I use the more aggressive matrix (put 1 as first number). The blocks are mostly gone and it increases compression as well.

SmoothHiQ should give similar results but I think that Convolution3d's main advantage is that it does both spatial and temporal smoothing, which in my case has been very welcome.

[vidiot]

@Boulder:

CNR2 works like a charm (at least for me).
It reduces much of the (chroma-)noise in (my) tv captures.

It´s kind of useless with clean DVD source though...

Parameters can be edited (Marc FD has already included a small readme), but otherwise worked o.k. with standard settings.
" CNR2()"

For me it works 2 to 3 times faster than the original VD one.

[Boulder]

I tried it on a TV capture but there was no effect, strange.

The script was like this:

LoadPlugin("c:\windows\system\cnr2.dll")
clip=AVISource("c:\temp\capture.avi")
clip2=AVISource("c:\temp\capture.avi").CNR2()
Subtract(clip,clip2)

There was no visual effect. As I said, I also tried the script Marc used to compare the effect but that didn't work either! I'd very much like to use the filter as it might get rid of the slight rainbow noise occurring in the subtitles in the captures.

[wotef]

if you want a brute force approach, (depending on the horribleness of the blocking) try 2d cleaner optimised 15,2,5 followed by bilinearesize (320,240) and then bicubicresize back to the original frame size, then layer it to the original image using "add" about 100 or so

import("vdub_filters.avs")
clip=clip
clip1=clip1.converttorgb().vd_2dcleaneroptk7(15,2,5).bilinearresize(320,240).bicubicresize(640,480,0,0.5).converttoyyu2()
clip2=layer(clip,clip1,"add",100,use_chroma=true)
return clip2