ColorMatrix v2.3

[henryho_hk]

Can ColorMatrix derive the "interlaced" parameter from specified d2v file?

Search => http://forum.doom9.org/showpost.php?...&postcount=246

[Wilbert]

No, it can't. Afaik you can't decide on basis of the d2v whether your clip is interlaced or progressive.

[Sharro]

Originally Posted by Wilbert

No, it can't. Afaik you can't decide on basis of the d2v whether your clip is interlaced or progressive.

Originally Posted by neuron2

No, because the stream might not be progressive. And no, DGIndex cannot rely on the pogressive frame flag as it often lies.

Wilbert and neuron2 should be right

All the best,

Sharro

[12monkeys]

What should I set the interlaced parameter to if I am dealing with progressive encoded as interlaced?

[Guest]

That's controversial. I'm in the camp that says to treat it as progressive. My AutoYUY2() filter is interesting in this regard:

http://neuron2.net/autoyuy2/autoyuy2.html

[Jeremy Duncan]

If I calibrate my monitor to Rec.601, and use colormatrix to then convert the Rec.601 to Rec.709.
Will my monitor calibration transfer from Rec.601 to Rec.709 ?
So it's as if I calibrated my monitor to Rec.709 specifications ?

[new7up]

all link bad, I can't downland it.can repair it?

[Guest]

Which link are you having trouble with?

[Jeremy Duncan]

Originally Posted by Jeremy Duncan

If I calibrate my monitor to Rec.601, and use colormatrix to then convert the Rec.601 to Rec.709.
Will my monitor calibration transfer from Rec.601 to Rec.709 ?
So it's as if I calibrated my monitor to Rec.709 specifications ?

What I do (I'm not sure this is the correct way), is calibrate my monitor to Rec.601 then use colormatrix. I tried to calibrate my monitor using Colormatrix and a Rec.601 calibration disk and I couldn't do it.

Colormatrix is a color upconverter. So I'm figuring it'll upconvert a monitor calibrated to Rec.601, to Rec.709 or HDTV standard.

So far I like the results.

Can somebody please confirm if my meathod is correct ?
Please.

[Jeremy Duncan]

Tritical, Your colormatrix.dll version 2.1 is broken.

Link

Originally Posted by dr1394

The 601 and 709 matrices only effect colors. Cb and Cr are equal to 128 when there is absence of color (black, white, gray, BTB, WTW). Both matrices will output the same RGB values when Cb and Cr are 128. Just look at the equations:

601
R = Y + 1.371(Cr - 128)
G = Y - 0.698(Cr - 128) - 0.336(Cb - 128)
B = Y + 1.732(Cb - 128)

709
R = Y + 1.54(Cr - 128)
G = Y - 0.459(Cr - 128) - 0.183(Cb - 128)
B = Y + 1.816(Cb - 128)

When Cb and Cr are 128, both equations become R = G = B = Y.

Ron

The BTB, and WTW changes with Colormatrix version 2.1
I've tested bt601tobt709.dll and there was no change in BTB, WTW when I tested Rec.601, Rec.709

[tritical]

You can test for yourself using blankclip that colormatrix does not alter luma values when both chroma planes = 128, regardless of source/dest. Perhaps you have scaling=0 (which clips input and output to 16-235/16-240) when you actually want scaling = 1 or 2?

[Jeremy Duncan]

Tritical,

My Dell Notebook LCD cannot calibrate the Contrast as well as a expensive monitor, and the very light colored bars in the Getgray Caldisc contrast pattern are not visible unless I use FFDshow Levels.

So I set FFDshow levels and the very light Contrast color bars were visible.
I then lowered the Levels tweak, so that I could just barely see the lightest contrast bars.
I then set the Colormatrix version 2.1 into FFDshow's avisynth.
I set it to convert Rec.601, to Rec.709.

Now, I have the Levels set so that the contrast pattern is barely showing it's lightest white bars. And I have Colormatrix ready to use.
- I check the FFDshow Avisynth box and activate Colormatrix.
The lightest white bars Disappear !

I do the very same test with the other plugin I linked to, and the lightest white bars did not disappear.
Both plugins did change the rgb colors too.

So I don't know what test you did, but I saw it with my own eyes.
Maybe you better double check.

Edit. I'm only using this code;
ColorMatrix(mode="Rec.601->Rec.709")

[tritical]

I tested that using colormatrix on a black and white clip (both chroma planes = 128) is a nop, as it should be. However, if you set scaling = 0 (which is the default value) then the input and output luma values will be clipped to 16-235 range. This is probably why the lightest bars disappear. If you want to keep the full 0-255 range then use scaling=1 so that the clipping doesn't occur.

ColorMatrix(mode="Rec.601->Rec.709",scaling=1)

The scaling parameter is explained in the readme.

[Jeremy Duncan]

Originally Posted by tritical

I tested that using colormatrix on a black and white clip (both chroma planes = 128) is a nop, as it should be. However, if you set scaling = 0 (which is the default value) then the input and output luma values will be clipped to 16-235 range. This is probably why the lightest bars disappear. If you want to keep the full 0-255 range then use scaling=1 so that the clipping doesn't occur.

ColorMatrix(mode="Rec.601->Rec.709",scaling=1)

The scaling parameter is explained in the readme.

That fixed the problem. Thank you very, very much Tritical.

[Sharro]

Originally Posted by tritical

I tested that using colormatrix on a black and white clip (both chroma planes = 128) is a nop, as it should be. However, if you set scaling = 0 (which is the default value) then the input and output luma values will be clipped to 16-235 range. This is probably why the lightest bars disappear. If you want to keep the full 0-255 range then use scaling=1 so that the clipping doesn't occur.

ColorMatrix(mode="Rec.601->Rec.709",scaling=1)

The scaling parameter is explained in the readme.

Tritical is it my eyes tricking me on for no clipping + unscaled should be scaling=2 ?

From the readme:


o 2 - no pre/post clipping and unscaled coefficients

All the best,

Sharro

[tritical]

You're correct that scaling = 2 is needed for no clipping + unscaled coefficients... scaling = 1 also has no clipping but uses scaled coefficients. In his case the difference doesn't matter since he is using a greyscale clip and both will give the same result (the output will be exactly the same as the input). If it wasn't a black/white clip then he'd have to determine which one is actually correct based on the origin of the clip.

[Sharro]

I got it tritical...but now I got confused, I always do my D2V's with PC Scale which I is full range 0-255 and mostly I'm doing Rec709 to Xvid so Rec601 and should be full range also.

Should I always use scaling=2 ?

Thanks.

Sharro

[Wilbert]

I got it tritical...but now I got confused, I always do my D2V's with PC Scale which I is full range 0-255

The range is always [16,235] YCbCr. So that PC Scale setting doesn't do anything, unless you use dgvfapi (which converts it to RGB).

[HeadBangeR77]

Originally Posted by Sharro

I got it tritical...but now I got confused, I always do my D2V's with PC Scale which I is full range 0-255 and mostly I'm doing Rec709 to Xvid so Rec601 and should be full range also.

Should I always use scaling=2 ?

Thanks.

Sharro

I've done some sample encodes using colomatrix, and haven't spotted any difference between those 3 scaling settings, although I sould have, actually.

Does the fact, that so called PC-Scale is suggested in my every d2v project could have an ifluence on that?

@ Wilbert: I've just marked your post: so what's the point in choosing between PC and TV-scale while doing a d2v project with DGIndex?

[tritical]

Yes, the PC scale setting in dgindex is somewhat strange and is only used if dgdecode is delivering rgb (either by dgvfapi or upconv=2). With pc scale it converts yuv->RGB(0-255) with tv scale it converts yuv->RGB(16-235). The conversion routines in dgindex/dgdecode all assume yuv 16-235 range (i.e. they use scaled coefficients). However, dgindex/dgdecode never actually clamp values to that range (either on output or on input to the color conversion routines), which makes it similar to scaling=1 in colormatrix.

Should I always use scaling=2 ?

If you are working with dvd footage then you should use scaling=0 or 1.

The thing to remember is that colormatrix simulates a yuv->rgb->yuv conversion. If you use scaling = 0 you are simulating yuv(16-235/16-240)->rgb(0-255)->yuv(16-235/16-240), where the yuv values are clamped before and after. With scaling = 2 you are simulating yuv(0-255)->rgb(0,255)->yuv(0-255). Scaling=1 is the same as 0 except that the yuv values aren't clamped to the 16-235/16-240 range before and after the conversion.