madVR - high quality video renderer (GPU assisted)

[dansrfe]

Is it possible to use the GPU on the dedicated graphics card alone or combined with the iGPU for all processing power used by madVR, etc. regardless of whether the monitor is connected to the motherboard's displayport/hdmi/dvi or the graphics card's?

EDIT: Nevermind, found the answer: http://www.lucidlogix.com/product-virtu-mvp.shtml http://www.lucidlogix.com/eshop.shtml#compare

Now the question is, will this virtual GPU work well with madVR? I'm not sure if the "HyperPerformance" and "Virtual Vsync" will work with madVR.

[dansrfe]

If I already have an 16bit ICC profile generated by an i1 DisplayPro is it possible to extract the 3DLUT from it? Or do I need to do some other steps to get the 3DLUT?

[e-t172]

Originally Posted by dansrfe

If I already have an 16bit ICC profile generated by an i1 DisplayPro is it possible to extract the 3DLUT from it? Or do I need to do some other steps to get the 3DLUT?

Yes, using the madVR ArgyllCMS procedure. Just skip everything before the collink step since you already have the ICC profile. You only have one command to run. You probably shouldn't disable GPU gamma ramps however, since the profile you're using is probably meant to be used with video gamma ramps.

[dansrfe]

Originally Posted by e-t172

Yes, using the madVR ArgyllCMS procedure. Just skip everything before the collink step since you already have the ICC profile. You only have one command to run. You probably shouldn't disable GPU gamma ramps however, since the profile you're using is probably meant to be used with video gamma ramps.

Super useful link thanks! I think I'll redo the icc profile generation with all the steps in the post to get a more accurate reading as well as use the 3DLUT in madVR with gamma ramps disabled which I've heard results in greater output accuracy from madVR as well?

[jkauff]

Originally Posted by dansrfe

Now the question is, will this virtual GPU work well with madVR? I'm not sure if the "HyperPerformance" and "Virtual Vsync" will work with madVR.

I've had no luck getting Virtu MVP and madVR to work together. You can add a player application to the Virtu list in iMode, but when you do madVR refuses to run. I've never tried it with the display connected to the iGPU--that causes my normal apps to use the iGPU unless specifically set to dMode in Virtu. I've come to the conclusion that Virtu MVP is essentially for gamers using the dGPU who still want to use the iGPU for video processing (using QuickSync).

You can use Eric Gur's QuickSync decoder in LAV and ffdshow without Virtu when the iGPU is not connected to the display. You need a motherboard that allows you to enable dual GPUs in the BIOS, and then you create a "fake" display for the iGPU in Windows Display Resolution page. You can follow Eric's instructions in the QuickSync thread in the Video Encoding section of the board.

[ginhead]

has anyone had any issues with madNvLevelsTweaker working with the latest Nvidia drivers (I'm using 320.49). I see no change to any output after running this tool. are there specific registry edits I can check to see if the tweaker is working on my system?

btb/wtw clips when I set madvr to 0-255. I can see btb/wtw when I set madvr to 16-235, but I see a lot of banding in grayramp from madTestPatternSource. from what I've read I'm guessing that the gpu is still sending out 16-235. setting madvr to 16-235 results in a scaling of the full 0-255 output, so I see the full signal but also get banding. and there is also the nagging feeling of this not being setup correctly.

i've tested this using a panasonic plasma (set to full range) connected via HDMI and a pc monitor with a straight dvi-dvi connection. I was expecting the dvi-dvi monitor connection to send btw/wtw with madvr set to full range, but even this is not working correctly.

i've also read about editing the ini file during driver install to get full range. I'll probably try that tomorrow. and/or look into getting an ATI card.

[dansrfe]

madshi, I wonder if it's possible to have madVR to run a quick query for other discrete GPUs and possibly parallelize usage of multiple GPUs for processing? Software SLI essentially.

If the monitor is connected directly to the motherboard, madVR could bypass the iGPU and use any and all discrete graphics cards connected to the motherboard. Assuming of course that SLI isn't enabled already. I know that this would probably be at the the bottom of your list or not on it even if this was possible however, just thought I'd ask.

[ginhead]

Originally Posted by dansrfe

Apparently, the last beta update came with a bunch of issues for a lot of people. My monitors quit being recognized right after I installed and rebooted so I had to revert back to the latest stable. Not sure if this also affected what madNvLevelsTweaker does though.

thanks! I am using the last released version (not beta) but this might be part of the problem. Any recommendation on a recent version that is known to work?

I did just test my HD4000 and the dvi-dvi-monitor setup. Same result. It would be nice if I could find some combination that worked as expected.

[dansrfe]

Originally Posted by ginhead

thanks! I am using the last released version (not beta) but this might be part of the problem. Any recommendation on a recent version that is known to work?

I did just test my HD4000 and the dvi-dvi-monitor setup. Same result. It would be nice if I could find some combination that worked as expected.

Yeah I deleted my post after I saw you were using the latest stable haha.

The levels tweaker should work with the latest stable. Just checked. Did you reboot after applying the tweak?

[Vyral]

Originally Posted by e-t172

Yes, using the madVR ArgyllCMS procedure. Just skip everything before the collink step since you already have the ICC profile. You only have one command to run. You probably shouldn't disable GPU gamma ramps however, since the profile you're using is probably meant to be used with video gamma ramps.

Should I use the ICC profil provided with my display drivers to create a 3DLUT file or should I create my own ICC profil ? What is the best thing to do ?

[Qotscha]

Originally Posted by ginhead

has anyone had any issues with madNvLevelsTweaker working with the latest Nvidia drivers (I'm using 320.49). I see no change to any output after running this tool. are there specific registry edits I can check to see if the tweaker is working on my system?

btb/wtw clips when I set madvr to 0-255. I can see btb/wtw when I set madvr to 16-235, but I see a lot of banding in grayramp from madTestPatternSource. from what I've read I'm guessing that the gpu is still sending out 16-235. setting madvr to 16-235 results in a scaling of the full 0-255 output, so I see the full signal but also get banding. and there is also the nagging feeling of this not being setup correctly.

i've tested this using a panasonic plasma (set to full range) connected via HDMI and a pc monitor with a straight dvi-dvi connection. I was expecting the dvi-dvi monitor connection to send btw/wtw with madvr set to full range, but even this is not working correctly.

i've also read about editing the ini file during driver install to get full range. I'll probably try that tomorrow. and/or look into getting an ATI card.

If you want to see BTB/WTW correctly, madVR must be set to 16-235, GPU to 0-255, and your display to limited range. This, however, will result in wrong colors everywhere outside madVR.

If madVR is set to 0-255, 16-235 is expanded to 0-255 and BTB/WTW are clipped.

Here is madshi's configuration recommendation.

[e-t172]

Originally Posted by Vyral

Should I use the ICC profil provided with my display drivers to create a 3DLUT file or should I create my own ICC profil ? What is the best thing to do ?

It's almost always better to generate your own profile since the one provided with the display obviously cannot take manufacturing variations into account. Of course the downside is, you need color measurement hardware (such as an i1 Display Pro) to be able to generate the profile yourself.

[dansrfe]

It doesn't actually mention in the madVR - ArgyllCMS thread whether or not to apply the icm file within windows as well. Is there a different procedure for that or can we just apply the profile generated in step 7?

In combination with disable GPU gamma ramps it should work correctly that way right?

[e-t172]

Originally Posted by dansrfe

It doesn't actually mention in the madVR - ArgyllCMS thread whether or not to apply the icm file within windows as well. Is there a different procedure for that or can we just apply the profile generated in step 7?

In combination with disable GPU gamma ramps it should work correctly that way right?

"Apply the ICM file within Windows" is a very vague concept which could mean a number of different things depending on the assumptions you make. While an ICC profile is originally meant to contain only purely profiling information (i.e. a description of the device's color response), it has since been overloaded to also contain calibration information in the form of so-called "Video Card Gamma Tables" (vcgt tag) which is meant to be loaded in the GPU.

It doesn't really matter if you configure your device to use an ICC profile in the Windows Color control panel applet, because that only applies to applications which include a CMM (Color Management Module) and choose to use the Windows configuration to get the current monitor's profile so that they can do their transformations. Web browsers and image editing software typically are in this category. Sadly, madVR is not one of them (and that's unfortunate, hopefully madshi will implement it at some point in the future).

Now - and this is where it gets really confusing - this configuration information is also used by small tools typically called loaders (which are typically bundled with color calibration software, though there is a free one called xcalib) that run discreetly on Windows startup and whose sole purpose is to take the vcgt (gamma tables) information from the profile which is currently configured in the Windows configuration and apply it in the GPU. These loaders don't look at the profiling information at all, and in that sense they are the exact opposite of the applications above.

So, should you load GPU gamma tables or not? Well, if your profile contains vcgt information (most of them do), then yes you should, because the rest of the profile, and by that I mean the profiling information, describes the behavior of the device with the vcgt applied. So if you're using the profile without loading its gamma tables, the result will be wrong.

If you are generating a profile purely for use with madVR, then you should generate a profile without any vcgt information (Argyll has options for that), because that removes one processing step which is likely to be better done by madVR since it does proper dithering, which might or might not be the case of the gamma tables implementation of your GPU. However, if you are using other, non-ICC-aware applications (such as games), then you might want to use the calibration provided by the gamma tables.

There is also a way to use Argyll to cleanly remove vcgt information from a profile and end up with a profile that describes the device without the vcgt applied, I believe it is explained in the ArgyLL documentation.

[dansrfe]

Essentially, all I want is the main desktop interface, windows/irfan image viewers, and web browsers to acknowledge the profile as well as madVR.

If I understood correctly, it would be best to create a profile without the videoLUT via Argyll with which I can configure to be used by the device in question in the Windows Color Management panel AND use the 3DLUT generated from this profile in step 8 with madVR. What effect would "disable GPU gamma ramps" have in this scenario? Wouldn't that option be a placebo since the profile that was applied in the color management module doesn't include the videoLUT?

Now, as you've said, without the videoLUT information presnt in the profile, the profile produces the correct result without the use of a loader during Windows startup which is a plus point. However, would this produce a less accurate result than creating a profile that includes the videoLUT?

What is the point of the videoLUT in the first place if it is not accurate enough for madVR and it has to be manually loaded during Windows startup if the profile was created with the videoLUT?

I'm not sure I understand the reason to even create profiles with videoLUTs if the benefits of creating profiles without them via Argyll allow you to load the profile without a loader.

Also, on a side note, I'm currently using the ICM profile that I got from someone else who calibrated the same monitor using an i1 Display Pro. When I launch madVR with "disable GPU gamma ramps" unchecked, madVR definitely adheres to the profiling information loaded within the color management module. It shows the corrected colors from the profile in windowed/overlay/exclusive modes as well. Maybe I've misunderstood the functionality of "disable GPU gamma ramps"?

[e-t172]

Originally Posted by dansrfe

Essentially, all I want is the main desktop interface, windows/irfan image viewers, and web browsers to acknowledge the profile as well as madVR.

For applications to "acknowledge the profile", they need to be written with ICC profiles in mind, in other words, they must include a CMM. Most web browsers do. The Windows desktop, probably not. Image viewers, I'm not sure.

Originally Posted by dansrfe

If I understood correctly, it would be best to create a profile without the videoLUT via Argyll with which I can configure to be used by the device in question in the Windows Color Management panel AND use the 3DLUT generated from this profile in step 8 with madVR. What effect would "disable GPU gamma ramps" have in this scenario? Wouldn't that option be a placebo since the profile that was applied in the color management module doesn't include the videoLUT?

Yes. If you're not using a profile with vcgt information, "disable GPU gamma ramps" shouldn't do anything. In theory. In practice there are some badly-written applications (e.g. Crysis) that act very rudely and set the GPU gamma ramps to something else without setting them back afterwards, so it's still better to keep this option checked to make sure you're in a known state when you're using madVR.

Originally Posted by dansrfe

Now, as you've said, without the videoLUT information presnt in the profile, the profile produces the correct result without the use of a loader during Windows startup which is a plus point.

Yes, although I would be wary of calling it a "plus point". Calibration can actually be useful because it allows applications that don't support ICC (e.g. games) to have more linear color response and a more appropriate white point. As I said, figuring out what the optimal solution is can get confusing very quickly.

Originally Posted by dansrfe

However, would this produce a less accurate result than creating a profile that includes the videoLUT?

In applications that support ICC, or if you use a 3DLUT generated from the ICC profile in the case of madVR, the profile accuracy should be pretty much the same. However, as I said above, for applications that don't support ICC or 3DLUTs, videoLUT calibration will give better results than doing nothing.

Originally Posted by dansrfe

What is the point of the videoLUT in the first place if it is not accurate enough for madVR and it has to be manually loaded during Windows startup if the profile was created with the videoLUT?

Good question. videoLUTs are useful to improve the output of applications that don't support ICC profiles (e.g. games). In addition, videoLUTs have 16-bit output precision, so they can actually improve the behavior of the device in ways that are not possible with software CMMs if and only if you have a 10 bit or more output. Ironically, that was actually the case in the past when using VGA (which is analog so you can technically output more than 8-bit), which explains why videoLUTs exist in the first place. In addition, AFAIK video LUTs existed before ICC was introduced.

Originally Posted by dansrfe

I'm not sure I understand the reason to even create profiles with videoLUTs if the benefits of creating profiles without them via Argyll allow you to load the profile without a loader.

Again, that's because videoLUTs are applied even to applications that don't support ICC. Now don't get me wrong, it won't completely fix the colors for these applications (for several reasons, one of them being that you can't do everything you want with a 3x1D-LUT as opposed to a 3DLUT), but it's still better than nothing.

Originally Posted by dansrfe

Also, on a side note, I'm currently using the ICM profile that I got from someone else who calibrated the same monitor using an i1 Display Pro. When I launch madVR with "disable GPU gamma ramps" unchecked, madVR definitely adheres to the profiling information loaded within the color management module. It shows the corrected colors from the profile in windowed/overlay/exclusive modes as well. Maybe I've misunderstood the functionality of "disable GPU gamma ramps"?

By "color management module" I assume you mean the Windows color control panel applet (which is not a CMM, it's just a configuration interface that doesn't do anything itself). If you are not using a 3DLUT within madVR, the "corrected colors" you're seeing is simply the result of the vcgt gamma ramps being loaded into the GPU - which, again, is not enough to get accurate color, but, again, is still better than nothing, hence your impression that the colors are "corrected" - yes they are, but not completely. Specifically, white point, gray scale and gamma is corrected, but not hue nor saturation. To get fully accurate color reproduction you need to use a 3DLUT.

[dansrfe]

Originally Posted by e-t172

By "color management module" I assume you mean the Windows color control panel applet (which is not a CMM). If you are not using a 3DLUT within madVR, the "corrected colors" you're seeing is simply the result of the vcgt gamma ramps being loaded into the GPU - which, again, is not enough to get accurate color, but, again, is still better than nothing, hence your impression that the colors are "corrected" - yes they are, but not completely. Specifically, white point, gray scale and gamma is corrected, but not hue nor saturation. To get fully accurate color reproduction you need to use a 3DLUT.

Yes, I'm referring to the Windows color control panel (colorcpl.exe). So, that's probably why I perceive corrected white point, gray scale, and gamma on everything on the desktop. So, does that mean that the color control panel is actually a loader? If so it seems to apply the profile that contains the videoLUT automatically upon login for me. Sometimes I have to click "Set as Default Profile" again after a driver update though.

So, I think I've closed in on the question that really isn't making sense to me now. What does the ICC profile have without the videoLUT? What does the "profiling" information do? Is the profiling information for color/hue saturation? Is this what an application with a CMM will further correct? How does creation of an ICC profile without a videoLUT affect the color/hue saturation readings in the profile?

Does this mean that a 3DLUT contains measurements of profiling information such as color/hue saturation AND the videoLUT and directly loads them into the lookup tables in the GPU? Is this why it is more accurate then including a CMM in madVR and utilizing profiling and videoLUT information? If so, shouldn't 3DLUT be the standard instead of fragmented ICC profiles which may or may not contain the videoLUT and whose profiling information may or may not be applied by an application unless it has a CMM?

[Delerue]

It seems that smooth playback isn't working anymore with 0.86.10 as video stutters sometimes (23.976 FPS with 24 Hz).

[e-t172]

Originally Posted by dansrfe

Yes, I'm referring to the Windows color control panel (colorcpl.exe). So, that's probably why I perceive corrected white point, gray scale, and gamma on everything on the desktop. So, does that mean that the color control panel is actually a loader? If so it seems to apply the profile that contains the videoLUT automatically upon login for me. Sometimes I have to click "Set as Default Profile" again after a driver update though.

The Windows color control panel applet is not a loader. Well, at least not by default - apparently you can make it a loader by enabling an obscure advanced option, I'll have to check.

If you see the video LUTs being changed during login, it probably means you have a loader being started upon Windows startup that you don't know about. For example the loader bundled with i1 profiling software is called "XRGamma.exe".

Originally Posted by dansrfe

So, I think I've closed in on the question that really isn't making sense to me now. What does the ICC profile have without the videoLUT? What does the "profiling" information do?

In itself, nothing. The profiling information describes the color space of the device by describing a transformation between RGB triplets as displayed by the screen and real absolute color values (CIEXYZ or CIELAB). In other words, the profiling information answers the question "if I send RGB triplet (r, g, b) to the screen, what color do I get?". Using this information, CMMs are able to accurately translate between the color space of the input source (e.g. an sRGB image, or in the case of madVR, a BT.709 video) and the color space of the output device, thus achieving accurate color reproduction.

Bottom line: profiling information is used by CMMs to determine how to accurately produce a given color using your device.

Originally Posted by dansrfe

Is the profiling information for color/hue saturation?

It's for everything: hue, saturation and luminance.

Originally Posted by dansrfe

Is this what an application with a CMM will further correct?

Well, it's more complicated than that (or simpler, depending on your perspective). The way a CMM works, you have an input colorspace (typically sRGB, Adobe RGB, BT.709), and an output color space (described by your device profile). The CMM is simply a converter: it uses complicated algorithms (gamut mapping) to make sure colors in the input colorspace are accurately reproduced in the output color space. My point is, the CMM calculations are dependent on the input color space.

Video LUTs, on the other hand, are applied to everything and do not care what the input color space is, which is why they're quite limited in what they can do.

Originally Posted by dansrfe

How does creation of an ICC profile without a videoLUT affect the color/hue saturation readings in the profile?

Well, if you generate an ICC profile without a videoLUT, the profile will describe the device's behavior without a videoLUT. If you generate a profile with a videoLUT, the profile will describe the device's behavior with a videoLUT. A videoLUT cannot affect the hue and saturation of the primaries, but it can affect the hue and saturation of non-primary colors, though technically that's just a side effect.

Originally Posted by dansrfe

Does this mean that a 3DLUT contains measurements of profiling information such as color/hue saturation AND the videoLUT and directly loads them into the lookup tables in the GPU?

A 3DLUT is not loaded into the GPU lookup tables. GPUs don't support 3DLUTs directly. What madshi did in madVR is he implemented 3DLUT support himself using custom GPU shader code.

Basically, a 3DLUT is just a CMM: it converts from one color space to another. However, in the case of a CMM the transformation (3DLUT) is calculated on-the-fly depending on the input and output color spaces, as opposed to a static 3DLUT where the input and output color spaces are chosen when generating the 3DLUT. The 3DLUT doesn't contains "measurements" or even a profile: it is generated from them.

Originally Posted by dansrfe

Is this why it is more accurate then including a CMM in madVR and utilizing profiling and videoLUT information?

Not sure what you mean by that.

Originally Posted by dansrfe

If so, shouldn't 3DLUT be the standard instead of fragmented ICC profiles which may or may not contain the videoLUT

Define "fragmented". Why is it a problem that an ICC profile may or may not contain a vcgt? Assuming your system is configured correctly, if it contains a vcgt it will be applied, and then as long as it's applied the profiling information is correct.

Originally Posted by dansrfe

and whose profiling information may or may not be applied by an application unless it has a CMM?

Well it's the exact same problem with 3DLUTs: what if an application doesn't support 3DLUTs? Keep in mind that CMMs are superior to 3DLUTs (in fact, they are a generalization of 3DLUTs) because they are able to transform between two arbitrary color spaces on the fly, while a static 3DLUT is limited to a single transformation between two predefined color spaces.

Also, keep in mind that to do color correction you need to know the input color space, and only applications know that information, so you need application support anyway. Though one could make a case about assuming sRGB as a default input color space.

[Thingol]

Webcam does not work in MPC-HC, but works in PotPlayer with madVR. Strange