Chroma Smoother

[DrEaMeR86]

Hi! I was wondering if the "chroma smoother" from VirtualDub(mod) is available as avisynth plugin.

I'm working with a DVD and the filter:
chroma smoother (mode: 4:2:0 MPEG-2) is all I need to deal with the red color.

[scharfis_brain]

mergechroma(blur(1))

[DrEaMeR86]

It becomes blurry :s

[scharfis_brain]

so what do you expect?

[DrEaMeR86]

Ok, look at the pictures.

original:
http://img397.imageshack.us/i/original.png/
http://img82.imageshack.us/i/2original.png/

mergechroma(blur(1)):
http://img379.imageshack.us/i/blur.png/
http://img32.imageshack.us/i/2blur.png/

Vdub chroma smooth
http://img73.imageshack.us/i/perfect.png/
http://img76.imageshack.us/i/2perfect.png/

[kemuri-_9]

is LoadVirtualDubPlugin() not working for you?

[LoRd_MuldeR]

is LoadVirtualDubPlugin() not working for you?

But the "Chroma Smoother" is an internal filter. There's no Plugin to load (except an "external" version exists somewhere).

[kemuri-_9]

Ah, my fault, I never use vdub filters, so i had forgotten that there were some internal ones.
the description of the filter says "Applies linear interpolation to point-upsampled chroma without affecting luma"
that more sounds like it's using point up and downsampling in some fashion to get a blur effect...

[Gavino]

Here is the full description of the VDub filter:
Video compression algorithms often store color (chroma) information at a lower resolution than grayscale brightness information, since the eye is less sensitive to detail in color; however, some video codecs don't interpolate chroma well on decompression, resulting in blockiness around sharp color transitions. The chroma smoother filter attempts to apply a blur solely in the color channels to correct this situation.

Each chroma option in chroma smoother's configuration corresponds to a blur that is tuned for a particular type of chroma subsampling; assuming that the video decoder did not interpolate chroma at all, choosing the correct setting will produce a result approximating bilinear interpolation. Of course, stronger or weaker options can be picked to taste.

[DrEaMeR86]

Ok, actually I don't care if it is the same filter or not. What I want is the same result, I've been playing with some filters but I couldn't get the same result.

What would you use?

[thewebchat]

How about MergeChroma(PointResize(last.width*2,last.height*2).Sangnom.TurnLeft.Sangnom.TurnRight.BilinearResize(last.width,last.height))

[DrEaMeR86]

It does some chroma shifting. :S

[scharfis_brain]

you cannot get rid of this chroma-aliasing in YUV 4:2:0 colourspace (YV12) unless you are willing to blur the chroma or go to non-subsampled YUV 4:4:4 (which doesn't exsist in AVISynth).

You could go for RGB.
so converttorgb24() should do the trick for you.
BUT: you cannot compress RGB or YUV444 with any MPEG-ish codec.

I suggest you to use ffdshow as output rendering filter and set the output to RGB24 or RGB32
as well as using the "High Quality YV12 to RGB conversion" of ffdshow

[DrEaMeR86]

Ok, thanks a lot.

[kemuri-_9]

or go to non-subsampled YUV 4:4:4 (which doesn't exsist in AVISynth).

should probably choose your words a bit more carefully as it does exist, just in avisynth 2.6 which has no official releases as of yet.

2.6 adds Y8 (luma only), YV16 (4:2:2), YV24 (4:4:4), and YV411 (4:1:1) colorspaces.

[scharfis_brain]

YUV444 practically is unavailable in AVS until now.
So I don't think I chose my words wrong....