madVR - high quality video renderer (GPU assisted)

[hozes]

Originally Posted by nevcairiel

That's not true. The chroma scaling and the rgb conversion already make dithering mandatory. Range conversion just slightly changes the coefficients used for the rgb conversion, it doesn't add a new step in the process.

i just ask about the color production and blacks...

which option gives the truest color production and blacks for movies

[James Freeman]

Originally Posted by nevcairiel

That's not true. The chroma scaling and the rgb conversion already make dithering mandatory.

@nevcairiel
I learn something new everyday.
Can you please elaborate (loosely) how Dithering is needed for Chroma Scaling and YUV -> RGB conversion?

Thanks

@hozes
Use Nev's option (1).

[huhn]

Originally Posted by James Freeman

@nevcairiel
I learn something new everyday.
Can you please elaborate (loosely) how Dithering is needed for Chroma Scaling and YUV -> RGB conversion?

Thanks

@hozes
Use Nev's option (1).

chroma upscaling is done in 16 bit, so the hole picture is 16 bit. do you need more informations?

and at giving a tv limited that can do both limited and unlimited, don't you think the tv has to do limited -> unlimited conversation and i don't think a tv does this in 16 bit. and black is still 0 so even with a 16 input the pixel has to be 0.

[James Freeman]

Originally Posted by huhn

chroma upscaling is done in 16 bit, so the hole picture is 16 bit. do you need more informations?

I don't think UPscaling is what nevcairiel meant.
As far as I understand, Upscaling does not need Dithering at all.
There is probably some kind of YUV->RGB conversion/extraction that needs dithering to be accurate.

Originally Posted by huhn

and at giving a tv limited that can do both limited and unlimited, don't you think the tv has to do limited -> unlimited conversation and i don't think a tv does this in 16 bit.

IMO the quality of the range conversion (resulting banding or not) depends on the quality of the TV.
Most likely than not, the native range of HDMI is Limited TV range (16-235) and it is band-less, unless the TV is really crappy.
Most of the Satellite boxes and Blu-Ray/DVD players are also 16-235 range.

Originally Posted by huhn

and black is still 0 so even with a 16 input the pixel has to be 0.

If the TV is in PC/Full range, this statement is true.

One thing you have to know; You have to understand TV's visible (displayed) black and input signal black.
When you select Limited/TV range in the TV, the displayed black that the TV shows you will be expected at step 16 of the input signal.
When you select Full/PC range in the TV, the displayed black that the TV shows you will be expected at step 0 of the input signal.

[hozes]

is btb/wtw is important for color production or for blacks...
i am wanna learn whats is the truest option for watching movies...

for eq, movies lik batman dark knight, blacks areimportant and full rgb and limited rgb affects too much, with limited rgb the screen seems to dark, with full rgb the screen seems brighter, blacks are less black...

which one is correct for true production of black

[vivan]

Originally Posted by James Freeman

I don't think UPscaling is what nevcairiel meant.
As far as I understand, Upscaling does not need Dithering at all.
There is probably some kind of YUV->RGB conversion that needs dithering to be accurate.

No, after any scaling you'll end up with floating point values. And to represent those fp values as integers you'll need dithering.
Let's take simple 1.5x bilinear scaling. You had 10 and 11, after scaling you'll have 10, 10.5 and 11.

[James Freeman]

Originally Posted by vivan

No, after any scaling you'll end up with floating point values. And to represent those fp values as integers you'll need dithering.
Let's take simple 1.5x bilinear scaling. You had 10 and 11, after scaling you'll have 10, 10.5 and 11.

You are absolutely right!
Thanks.

But how a Blu-Ray player does this (Chroma upscaling) without complicated dithering, and without introducing error?

If I'm not mistaken, the native output of a Blu-Ray player is YCbCr 4:4:4 (or 4:2:2), 16-235.
The question is can a PC (HDMI) + madVR output the same "kind" of signal like a stand alone blu-ray player without overprocessing it?

@hozes
No, BTB & WTW are NOT important for 100% full quality movie watching.
Use Nev's option (1).

[huhn]

Originally Posted by James Freeman

I don't think UPscaling is what nevcairiel meant.
As far as I understand, Upscaling does not need Dithering at all.
There is probably some kind of YUV->RGB conversion/extraction that needs dithering to be accurate.

ok i try it again.

chroma upscaling/up sampling is needed this creates flat point data stored at 16 bit integar so every bd gets up sampled and the picture is now 16 bit.
RGB -> YCrCb creates 32 bit float point too if a colorspace conversation is needed.

in any case you get 16 bit data and the best way to get this to 8 bit is dithering not rounding

IMO the quality of the range conversion (resulting banding or not) depends on the quality of the TV.
Most likely than not, the native range of HDMI is Limited TV range (16-235) and it is band-less, unless the TV is really crappy.
Most of the Satellite boxes and Blu-Ray/DVD players are also 16-235 range.

hdmi doesn't care if the data is limited or full range the bit are all the same it is tranfered as it is. if you change from unlimited to limted the tv gets now a stream with 16-235 but all information are in the stream even the 0-15/236-255.

and bd/dvd player aren't limited the source is limited and they simply decode it and change it to YCbCr 4:2:2/4:4:4 (this should be done with dither too...) so the tv gets the "same picture"/same range like it decodes the picture it self.

all non gaming consols/pc should always send limited because normal broadcast/DVD/BD even live stream from twitch/youtube are all limited and it should be excepted to be limited.

But how a Blu-Ray player does this (Chroma upscaling) without complicated dithering, and without introducing error?

they don't do this in 16 bit. but this can change from dvd/bd players maybe some use 10 bit bit if some of them dither i don't think so

and they can't send it untouched in 4:2:0 (now possible with hdmi 2.0) so they need it too.

If I'm not mistaken, the native output of a Blu-Ray player is YCbCr 4:4:4 (or 4:2:2), 16-235.
The question is can a PC + madVR output the same "kind" of singnal like a stand alone blu-ray player?

no MADVR can't do this MADVR output 8 bit RGB to the GPU.
you can send 4:2:2 or 4::4:4 YCbCr but this just make the picture worse are at least not better.
MADVR does a lot of this a lot better then every DVD/BD player

(1) TV accepts PC/Full levels: Set madVR to PC/Full, set GPU to PC/Full - This is usually considered the better option, if your TV can do it.

@hozes
nevcairiel provided all information you need to setup your pc/tv

1 is best then 2 (a) followed by 2 (b)

(2) TV accepts only TV/Limited levels:

(a) Set GPU to PC/Full and set madVR to TV/Limited
(b) Set GPU to TV/Limited and set madVR to PC/Full

nevcairiel provided all information you need to setup your pc/tv

1 is best then 2 (a) followed by 2 (b)

[hozes]

ok, i have a pioneer 428xd and it accepts all kind of colors...

is the full rgb in lav filter have any effect? it has also these settings, 16-255, 0-255 or untouched...

so i have set all of them to 0-255 full rgb full best and truest clolr production..thanks...

there is only one thing left, qb uses his plasma(lg) 1024x768@72hz.. my pioneer has also the same native resolution, but with cru, i cannot set it to 72hz whatever i do..does anybody advice how to set it 72hz, how another way?

[huhn]

Originally Posted by hozes

ok, i have a pioneer 428xd and it accepts all kind of colors...

is the full rgb in lav filter have any effect? it has also these settings, 16-255, 0-255 or untouched...

so i have set all of them to 0-255 full rgb full best and truest clolr production..thanks...

there is only one thing left, qb uses his plasma(lg) 1024x768@72hz.. my pioneer has also the same native resolution, but with cru, i cannot set it to 72hz whatever i do..does anybody advice how to set it 72hz, how another way?

The lavfilter settings have no effect on MADVR with normal contend, just leave them as they are.
the only thing you may need to change is HW decoding. you can enable ayuv but only if xy vsfilter and a unusual 4:4:4 8 bit source is used with subtitle.

[nevcairiel]

Originally Posted by James Freeman

@nevcairiel
I learn something new everyday.
Can you please elaborate (loosely) how Dithering is needed for Chroma Scaling and YUV -> RGB conversion?

Like others already pointed out, the conversion results in floating point data.

Simplified, and only for one color matrix, YUV -> RGB works like this: (without range change)

R = Y + 1.54 * (V - 128)
G = Y - 0.183 * (U - 128) - 0.45 * (V - 128)
B = Y + 1.81 * (U - 128)

(No guarantees for the exact coefficients, I just cobbled them together quickly)

As you can see, its quite odd values which are used here, which are guaranteed to produce odd results in 16-bit float.
If you want to convert that back to 8-bit integer for RGB output, you need to round, or better, dither!

Now if you want to do range expansion, the values used here just change slightly, and it looks like this:

R = 1.16 * (Y - 16) + 1.79 * (V - 128)
G = 1.16 * (Y - 16) - 0.213 * (U - 128) - 0.532 * (V - 128)
B = 1.16 * (Y - 16) + 2.11 * (U - 128)

No change in functionality, just a few changes in coefficients.

[vivan]

Originally Posted by James Freeman

But how a Blu-Ray player does this (Chroma upscaling) without complicated dithering, and without introducing error?

Who said that they don't introduce errors?
I doubt that they could be visible to a human eye, though.

[John Carmack]

Originally Posted by vivan

Who said that they don't introduce errors?
I doubt that they could be visible to a human eye, though.

This. People sometimes forget that DVD or Blu-ray players are just tiny computers with RISC CPUs.

[James Freeman]

Originally Posted by huhn

...in any case you get 16 bit data and the best way to get this to 8 bit is dithering not rounding

Thank You !
I realize Dithering is MUCH more important than I thought.

[Procrastinating]

I had not considered this, and I'm not sure how you would search for it, but does madVR select the most "ideal" of the input refresh rates? Ie will it choose 48hz for 24fps content, 47.952 for 23.976, 60hz for 30fps and so on? Assuming these are all indicated refresh rates in the settings.

In other words, does madVR select choose the refresh rate with the lowest remainder when starting the video?

[nevcairiel]

Originally Posted by Procrastinating

In other words, does madVR select choose the refresh rate with the lowest remainder when starting the video?

Yes, it does.

Easy enough to test for yourself as well, if you don't trust it.

[Procrastinating]

Originally Posted by nevcairiel

Yes, it does.
Easy enough to test for yourself as well, if you don't trust it.

Thanks, I didn't have enough sources at the time to test it

[huhn]

Originally Posted by Procrastinating

Thanks, I didn't have enough sources at the time to test it

you don't have mkv merge and a video file? X-)

[annovif]

Hello everyone, a friend of mine told me he is sure that our video card output can be 10 bit because hdmi 1.3 . To do so, i have to select ybcr 4:2:2 in the catalyst control panel. I'm not sure he is right , but i'm interested in it because my Sony panel are 10 bit native. He has a radiance too setted in that way , supported by Lumagen creator.
Another friend of mine has hacked an nvidia card to transform it in a Quadro card with 10 bit output. So is it true? Our video card are really 10 bit output?

Thanks

[James Freeman]

I wonder what madshi is cooking...