madVR - high quality video renderer (GPU assisted)

[Oguignant]

Originally Posted by Asmodian

Complete (full) range is preferred unless your display doesn't like it.

@Asmodian

But if I use full RGB with a TV, do not lose details?

Sorry for insist, I want to understand. I am very upset, but, I am reading contradictory information from this web:

RGB Full will display video games and other 0-255 content at the correct 0-255 range. TV, Movies and other video range use the RGB Limited range 16-235 .

http://referencehometheater.com/2014...ll-vs-limited/

Q: My TV supports Full mode, shouldn’t I use this?

A: No. TVs support Full to make them easier to calibrate. Most TVs will not display a black level below 16 because video content should never have it. By letting you see Black 15 or 14, it can make it easier to calibrate the display and get the black level correct. However, you really should not use this as your main setting as most displays are not designed to display levels below 16, and often introduce color tints when doing white levels past 240 or so. Additionally, if you restrict yourself to levels 16-235 you wind up with a brighter image with a better contrast ratio, as you can turn up the contrast level higher. Contrast Ratio is the thing your eye notices most, and so it will produce a more pleasing image.

[huhn]

ignore this link it is not about computer.

on a computer we have "full" control of the GPU output.

[QBhd]

Originally Posted by huhn

ignore this link it is not about computer.

on a computer we have "full" control of the GPU output.

Agreed.... that link is about StandAlone Players (Blu-Ray or Consoles).... nothing to do with madVR and PC's

QB

[Oguignant]

Originally Posted by huhn

ignore this link it is not about computer.

on a computer we have "full" control of the GPU output.

Perfectly clear. That's why I consult you here, are experts in these topics.

But I do not understand why the page says otherwise and gives incorrect information.

[Paul Tronc]

May I ask 2 little questions ?
1) I'm watching 1080p BluRay sources on a good 1080p REC709 projector, what's the ultimate algorithm to be used? Luma doubling + chroma doubling? I have an i7@4.4Ghz + GTX960.

2) I'm using 60Hz FRC via SVP. To make it work with madvr I have set the FFDShow Raw video filter + avisynth in MPCHC, together with LAV Video Filter (mandatory for Madvr), in external filters. Everything seems working fine. What I don't understand, is why don't I get frame dropping, as I reach 20ms average render time. Because SVP is supposed to work on the raw video, Madvr should see 60fps, and the render time should be under 16ms, isn't it? Frame dropping starts after 33ms render time, as if SVP was working after Madvr. Is it normal? Is it possible to change this?

[huhn]

i don't understand it too.

it is totally outdated. if your TV support correct full range RGB than there is nothing wrong in using it even with stand alone BD players.

[iSeries]

Hi,

It's generally accepted that going an all-PC levels chain is the way to go if you can. My TV can switch to PC levels but I do get more banding than if I output TV levels from MadVR and with TV set to TV levels (GPU at PC levels).

This may be a stupid question but I'm not sure how the conversions work. Eg with YCbCr luma goes to 235 but chroma goes to 240. When Madvr converts to RGB does it scale both luma and chroma to 235? What happens to the chroma information 235-240? And how does it handle WTW information, is that also all scaled to 235?

[Asmodian]

WTW (and BTB) is clipped, but is is clipped by the display when in limited range too so this isn't very different.

The 240 v.s. 235 is not an issue, the matrix converting YCbCr always uses 0-255 with different weights to go to limited or full range RGB, it is not a two step conversion to RGB, with one step doing the conversion and one scaling the range.

[iSeries]

Originally Posted by Asmodian

WTW (and BTB) is clipped, but is is clipped by the display when in limited range too so this isn't very different.

The 240 v.s. 235 is not an issue, the matrix converting YCbCr always uses 0-255 with different weights to go to limited or full range RGB, it is not a two step conversion to RGB, with one step doing the conversion and one scaling the range.

Thanks, although that does confuse me a little more. WTW is clipped by the TV when in limited range? With this chain: MadVR limited-GPU full-TV limited, I can see all the bars on the white clipping test up to 254. Is that not passing WTW? And when I have the whole chain at PC levels white is clipped at 235.

[CruNcher]

@madshi

do you think i reached the lowest possible overhead with MadVR comparing here against EVR Sync in a split load test ?



MadVR Performance Settings (low overhead)



interesting with MadVR MPC-BE shows in it's FPS counter 60 FPS measured not like with EVR Sync the exact 59.940 also if MadVRs Statistics shows that.

In Power output i measured around ~5W overhead vs EVR Sync for MadVR in that configuration.

But that's not even the worst case MadVR really seems to become more inefficient the more it's scaling even nearest neighbor becomes crazy inefficient fulllscreen and is tasking the GPU Shaders like crazy ???

[cork_OS]

Originally Posted by Paul Tronc

What I don't understand, is why don't I get frame dropping, as I reach 20ms average render time.

Did you disable smooth motion in madVR?

[Asmodian]

Originally Posted by iSeries

With this chain: MadVR limited-GPU full-TV limited, I can see all the bars on the white clipping test up to 254. Is that not passing WTW? And when I have the whole chain at PC levels white is clipped at 235.

If you can see WtW your display is not properly calibrated for limited range input, with limited range input 16 is 0% brightness and 235 is 100%. That means the display should never show blacker than black or whiter than white.

[CruNcher]

Ok lesson learned MadVR needs to be configured per source

Nearest Neighbor/Billinear = 200W
DXVA = 150W

Inline with EVR Sync now



Huh DXVA gets lost if nothing of the gui is being drawn ?

So there is no other way then to intentional downscale the image (draw a gui element, or resize it) or the overhead on the shaders will stay on billinear or nearest neighbor ?



So the middle layer is never low overhead except when using DXVA explicitly from the Decoder, and this isn't override able via the options at all ?

[iSeries]

Originally Posted by Asmodian

If you can see WtW your display is not properly calibrated for limited range input, with limited range input 16 is 0% brightness and 235 is 100%. That means the display should never show blacker than black or whiter than white.

I'm sorry but I don't think that's true. It's entirely correct that I would get BTB and WTW passed through with MadVR at limited range, GPU at Full range, and TV at limited range.

"Originally Posted by nevcairiel

For the level settings, there is basically 3 combinations of settings:

(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.

(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
In the second case, both a and b have small drawbacks.
With (a), you get crushed black/white on the desktop, but everything is perfect in madVR.
With (b), you get proper colors everywhere, except that the GPU is doing the PC range -> TV range conversion, which may not be the highest quality and end up in banding.

NEVER set both madVR to TV/Limited AND GPU to TV/Limited, you get double range compression.

Because of these drawbacks with either a or b, its usually recommended to use (1) if your TV accepts it. Its only "downside" is that BTB/WTW are lost, but its arguable if those are even worth keeping. If you insist on WTW/BTB, the 2a setting is probably the next best for video quality, if you can live with crushed black/white on the Desktop."

End quote. Now, whether or not to choose to clip WTW in the TV using the contrast control is up for debate and has been for years.

[Asmodian]

I wasn't trying to say the digital values for WtW and BtB never make it to the display, only that you never see them so whether they are clipped by madVR or displayed exactly the same as if they had been clipped doesn't make any difference to the image.

In this digital age I think it is totally appropriate that contrast is as high as possible, there is no analog uncertainty in a 100% signal so there is no reason to run below max contrast. Also contrast is the most limiting aspect of most modern displays, reducing contrast in order to "keep" WtW is a tragedy.

[CruNcher]

Ouch i looked at old issues virtually all of those are fixed (options added) in 0.91.5 and performance (stability) pretty awesome as well on low overhead config.

Core Render Performance on a really high level





Updating options in MPC-BE though still can cause to much CPU overhead causing frames to get dropped by MadVR when pushing "Apply"

Needs to be better separated from each other thread wise (async)

[ryrynz]

Originally Posted by iSeries

(2) TV accepts only TV/Limited levels:
(a) Set GPU to PC/Full and set madVR to TV/Limited

This is how I used to have my TV set up and wondered why everything was off.. My TV only accept 16-235 via HDMI unless I use CRU to remove the audio block then my TV exposes a full range input option.
I prefer to bitstream so I've decided to keep it with 16-235 output via the GPU control panel.

Not sure why using 0-255 output via the GPU with madVR set to 16-235 for the display looks different to the GPU outputting 16-235 with madVR set to 0-255 for the display..

Could be beneficial for madVR to have a level checker image included to perhaps assist users.

0-255 -> 16-235 vs 16-235 -> 0-255

[iSeries]

Originally Posted by Asmodian

I wasn't trying to say the digital values for WtW and BtB never make it to the display, only that you never see them so whether they are clipped by madVR or displayed exactly the same as if they had been clipped doesn't make any difference to the image.

In this digital age I think it is totally appropriate that contrast is as high as possible, there is no analog uncertainty in a 100% signal so there is no reason to run below max contrast. Also contrast is the most limiting aspect of most modern displays, reducing contrast in order to "keep" WtW is a tragedy.

Ah i see. Yes i generally agree, although the behaviour of the tv plays a big part in where contrast is set.

[Asmodian]

Originally Posted by ryrynz

0-255 -> 16-235 vs 16-235 -> 0-255

For the second screenshot it looks exactly like the GPU is still compressing the range. Are you sure the GPU is in full range?

Originally Posted by iSeries

Ah i see. Yes i generally agree, although the behaviour of the tv plays a big part in where contrast is set.

True, a lot of displays go very weird when contrast is set too high.

[ryrynz]

Originally Posted by Asmodian

For the second screenshot it looks exactly like the GPU is still compressing the range. Are you sure the GPU is in full range?

The second screenshot is 16-235 set via the GPU and madVR set to 0-255. This is near enough visually identical to 0-255 -> 0-255 output being used on this desktop PC.

For anyone interested in this video and others, link.