madVR - high quality video renderer (GPU assisted)

[Andy o]

BTW, I wonder if the next gen of AMD cards (http://www.anandtech.com/show/4455/amds-graphics-core-next-preview-amd-architects-for-compute) will make easier to program the hardware decoders. It would definitely make me stay with AMD for graphics, especially for madVR use.

[leeperry]

BTW, I wonder if the next gen of AMD cards (http://www.anandtech.com/show/4455/amds-graphics-core-next-preview-amd-architects-for-compute) will make easier to program the hardware decoders. It would definitely make me stay with AMD for graphics, especially for madVR use.
They're late to the party, and they know it. Most coders who master CUDA can't be bothered to learn a new architecture(especially when nvidia owns 60/65% of the market (http://www.bit-tech.net/news/hardware/2011/05/17/amd-graphics-cards-gain-market-share-from-n/1))....in the IT business, sleeping means losing. Google and m$ have learned it the hard way many times in the past.

But they need some proper workflow for their new APU's, so time will tell. They'll have to show the green to get ppl to develop for them, though.

[CruNcher]

Yep it was a perfect strategy from Nvidia to become so open and buildup this extreme nice ecosystem (including Vdpau) even for average joe developers without big hurdles, the cooperation on nvcuvid with donald was a big thing which helped everyone in this ecosystem and the doom9 community was on the front of this improvements :)
Though still for now ATI/AMD have the more efficient hardware (also UVD was capable of 2k before Nvidia now reached that point and doubled it again to 4k, though we all know the driver issues with a more open ecosystem it could have been avoided from the getgo, like the mentioned cooperation between donald and nvidia showed) the question though remains for how much more Generations ;) ? (Nvidia already shows that they make progress on their biggest weakness that is Power Consumption and efficiency/watt and the research on Kal-El will take part in further Desktop GPU improvements in those regards)
AtI/AMD still has a hard time outside of Games and now they opened up more with their SDK but yet i saw not 1 implementing their UVD not even all the Chinese 1 click converter no one yet implemented OVD for the UVD, except the bigo isvs ofcourse which already did still under NDA before public release back then :P
You can just guess that Nvidia had some rather clever guy sitting around in Nvidias management conferences who realized that balmers monkeydance back then had a reason and that it would be good to give more developer access and lower the hurdle of needing to sign a useless NDA after release for more consumer used parts ;)

[xv]

I have a little problem with madVR (LACUVID / ffdshow). In H.264 (and I think also in MPEG-2) streams the primaries/transferfunction and colormatrix can be set. Unfortunately this information is ignored. My DSLR (EOS 550d / Rebel X2i) for example uses bt709 primaries, bt709 transfer function and bt601 matrix, no matter if recording in SD or HD. So any auto-guessing by resolution is wrong.
Isn´t it possible that ffdshow/LAVCUVID passes this data to madVR if available and only if not available auto-guessing is used?

[cyberbeing]

With the move to a compute-focused Fermi-like SIMD architecture, that may be the end of AMD's low-cost & perf/watt advantage over NVIDIA, forcing them to build hot goliath chips to stay competitive. It could make the battle of next generation GPUs from both camps very interesting, especially in the HTPC space.

Yet after such a large architecture shift, even if accessing the decode hardware becomes easier with the new GPUs, all current AMD owners could easily get screwed if none of the new applications or features support or run well on their legacy VLIW GPUs. On the bright side, this could also mean that porting CUDA applications to run well on next-gen AMD GPUs may be realistic in the future, as the result of basic feature parity.

[CruNcher]

Though also here Nvidia has the advantage of being earlier in that Problem Zone of improving Power Consumption with their Goliath Chips, yep it will be interesting if Nvidia can improve faster then AMD/ATI port over their perf/watt onto "Southern Island" as we surely will see the first Power Consumption improvements for Nvidias Maxwell (backed up by Kal-El research) :). Hopefully it wont take long till the current P-State system becomes more dynamic like C&Q and Speedstep are even if they only reach the efficiency of the first generations of those 2/3 Generations we are in now with the CPU (especially intel porting over ATOM efficiency to the Desktop first).

[Portioli]

hello i am using mpc-hc last build (1.5.2.3246) lav splitter and madvr 0.65 and i have a problem.
when madvr switches to exclusive mode my screen freezes (while audio continues)
i tried it with pot player & various other decoders (ffdshow,cyberlink ham,core avc) and the problem remains.
i dont have problems with previous madvr releases

[leeperry]

i dont have problems with previous madvr releases
you may wanna provide logs, madshi doesn't have a divinatory gift I think ;)

[jmone]

Mmmm Good Idea and much cheaper! Unfortunatly, I know zip on Nvidia stuff (all ATI for years), SamuriHL suggests a GTS450 for madVR / LAV CUVID duties (I need a quiet low heat or back venting card to put in the Shuttle). Other suggestions?

Thanks for all the suggestons - got the GTS 450 Palit Half Height Card (vents out the back).

***EDIT - Too OT : Moved my issues to - http://www.avsforum.com/avs-vb/showthread.php?p=20591520#post20591520 any help would be great!
Thanks
Nathan

[jmone]

hello i am using mpc-hc last build (1.5.2.3246) lav splitter and madvr 0.65 and i have a problem.
when madvr switches to exclusive mode my screen freezes (while audio continues)
i tried it with pot player & various other decoders (ffdshow,cyberlink ham,core avc) and the problem remains.
i dont have problems with previous madvr releases

Interesting, there are a bunch of us seeing this issue with MC16 as well and I know the devs have been working on it over there.

[Portioli]

you may wanna provide logs, madshi doesn't have a divinatory gift I think ;)

I cannot do that.
Screen freezes.
I have to run task manager and shut down mpc-hc

[ney2x]

@Portioli - first, uncheck all colorspace under output in ffdshow video config leaving YV12 check.

I also experienced freezing problem if using my ATI 6850 and changing some madvr settings (present several frames in advance), but if I restore madvr's default, then freezing is gone.
- latest lav filters, ffdshow video, mpc-hc and reclock

No freezing problem if using any nvidia hardware (my gtx 260 [default madvr setting] and gtx 560 Ti [can change madvr settings]).
- latest lav filters, lav cuvid, mpc-hc and reclock.

In short, madvr and lav suite combination is perfect! And also latest hardware. That's only my opinion.

[Portioli]

@Portioli - first, uncheck all colorspace under output in ffdshow video config leaving YV12 check.




thanks man!
i had left NV12 ticked.
i dont know why i did that
but now it works perfectly

[cyberbeing]

For anybody in the market for a meter, X-Rite just released the i1Display Pro and ColorMunki Display colorimeters a few days ago (i1Display 2 is now discontinued). Both are supposed to be compatible with wide-gamut displays, with an affordable price point to boot. Some in-depth reviews are needed, but it could end up the perfect colorimeter for HTPC, wide-gamut displays, and PDPs.

[leeperry]

For anybody in the market for a meter, X-Rite just released the i1Display Pro and ColorMunki Display colorimeters a few days ago (i1Display 2 is now discontinued). Both are supposed to be compatible with wide-gamut displays, with an affordable price point to boot. Some in-depth reviews are needed, but it could end up the perfect colorimeter for HTPC, wide-gamut displays, and PDPs.
very nice! but until ARGYLL and Color.HCFR support them, they're pretty much useless to us :o

The latest non-public beta of Color.HCFR I have is said to support the Colormunki spectro, though. But I'm not shelling out half a grand to feed the colorimetry OCD'ed monster :D

[Xaurus]

I am unsure where to ask, but I recently acquired a few movies in a 1080i 29.97 fps format.

I am running 23.976 fps progressive videos without any problems,
fed directly to my plasma TV.

But this 1080i content proved to be hard to get right.
No matter what I did I could not get rid of "panning stutter".

So what is the best desktop resolution for 1080i content?

I tried 1080p / 29.97 but this had panning stutter, refresh
rate with CTRL+J was 29.97 so no problem here.

Then I tried 1080i / 29.97 and after checking CTRL+J with madvr the
screen was running at 59.94. The panning stutter was still present,
although perhaps slightly less obvious than on the previous resolution.

I am using mpc-hc, madvr, lavcuvid and lavfilters.
lavcuvid is set at 25/30 content.

:thanks:

[Andy o]

Your deinterlacing filter has to do inverse telecine and output 24p to madVR. Somebody linked to an IVTC filter a few pages back, you might wanna try that.

[Xaurus]

Your deinterlacing filter has to do inverse telecine and output 24p to madVR. Somebody linked to an IVTC filter a few pages back, you might wanna try that.
I have checked "Inverse telecine" in the Nvidia control panel, at least. I will check out IVTC. :)

So if it outputs 24p to madvr.. that means 24.0000 so
I can just set my plasma display to this frequency?

[Qaq]

So if it outputs 24p to madvr.. that means 24.0000 so I can just set my plasma display to this frequency?
23,976 to be exact. Much better.

[jmone]

I've been trialing a GTS450 nvidia card (been an ATI fan for years) to get access to CUVID but I've found an old issue (when I was trying Intel GPU's) where madVR will change the freq but then the playback is all "stuttery / out of sync" and drops frames till I do a STOP/PLAY cycle at which point it is perfect.

[HTPC-User]

Hi!


Concerning my partly grey OSD:
http://forum.doom9.org/showthread.php?p=1508029#post1508029

I will investigate this issue further in the next few days, but at the moment I am quite sure, that some parts of the OSD are always in green and some parts are in dark grey, no matter what color the background was.
So my first thought was that this might be an ATI bug or a projector problem.

By the way, how can I cross-check if the graphics card as well as the projector displays full RGB 4:4:4?

:thanks:

Ok, now I did some tests to locate the problem, why some parts of madVR's OSD are grey and the other parts are green.

Hopefully someone can give me a clue if the problem are the ATI drivers or the projector.

At first I made a screenshot of madVR being in windowed mode. Then I examined the screenshot on my computer CRT display: everything is fine, the OSD is completly green.

Then I displayed the screenshot on my projector, CCC set to RGB 4:4:4 -> some parts are green some parts gray. Moving the picture some pixels to the right or to the left, the gray parts don't move, it seems to be as if they stay at their original location, so now are others parts in gray. (I hope one can understand what I mean).

For the next test I set CCC to YCbCr 4:4:4 -> The same behavior as before, no difference.

At last I tried YCbCr 4:2:2 -> Now the OSD seems to be almost complete in green, but the picture quality decreases as the text seems to be somehow unsharp, not so clear and rich as before.
I think this is the result of a conversion between RGB 4:4:4 (madVR output) and YCbCr 4:2:2 done by the ATI driver/hardware?

Obviously my suspicion is right, it is not a madVR related problem, the problem is caused by the ATI CCC or the projector.

So can anyone definitely and for 100% sure confirm that the ATI Catalyst Center 11.1 (which I use) is capable of outputting RGB 4:4:4 without glitches and bugs?

Due to a lack of proper equipment, i.e. more displays, I can't do more comparative tests by myself.

:thanks:

[leeperry]

For anybody in the market for a meter, X-Rite just released the i1Display Pro and ColorMunki Display colorimeters a few days ago
and they're giving away the obsolete ones now(the i1lt runs the exact same hardware as the i1d2): http://www.buy.com/prod/x-rite-eye-one-displaylt-color-management-solution/q/loc/101/205985210.html

[Xaurus]

23,976 to be exact. Much better.
Yeah okay good, I have already set it up for 23.976 so that would be great.

But I thought that lavfilters/lavcuvid/madvr would be capable of deinterlacing on their own without the need of yet another program in the chain?

[Andy o]

I've been trialing a GTS450 nvidia card (been an ATI fan for years) to get access to CUVID but I've found an old issue (when I was trying Intel GPU's) where madVR will change the freq but then the playback is all "stuttery / out of sync" and drops frames till I do a STOP/PLAY cycle at which point it is perfect.

That happens with me only on windowed mode. When it switches to exclusive it gets smooth. Going back to windowed stutters again, but sometimes it just gets fixed.

[Andy o]

I have checked "Inverse telecine" in the Nvidia control panel, at least. I will check out IVTC. :)

So if it outputs 24p to madvr.. that means 24.0000 so
I can just set my plasma display to this frequency?

By "24p" I meant around 24p. If your content is 29.97i, then it should be IVTC'd to 23.976. The plasma (which?) should not be set to anything usually, you just need to output 24/23p with your videocard. madVR can do this automatically for you.

[Andy o]

Yeah okay good, I have already set it up for 23.976 so that would be great.

But I thought that lavfilters/lavcuvid/madvr would be capable of deinterlacing on their own without the need of yet another program in the chain?

maybe lavcuvid can do IVTC? I know it uses the hardware deinterlacing, and there is an IVTC checkbox in the Nvidia control panel. I don't know if it can tell automatically which content has been telecined, or if you can just force it, though.

IIRC when using TMT3 w/DXVA and playing 29.97 telecined content, I just had to set my card to 23p and it would do IVTC, but I'm not 100% sure, it's been a while.

[leeperry]

I've been trialing a GTS450 nvidia card (been an ATI fan for years) to get access to CUVID but I've found an old issue (when I was trying Intel GPU's) where madVR will change the freq but then the playback is all "stuttery / out of sync" and drops frames till I do a STOP/PLAY cycle at which point it is perfect.
that happens to me when I change something in my ffdshow Avisynth scripts...sometimes it fixes itself after a few secs, sometimes it requires a reseek.

[Xaurus]

By "24p" I meant around 24p. If your content is 29.97i, then it should be IVTC'd to 23.976. The plasma (which?) should not be set to anything usually, you just need to output 24/23p with your videocard. madVR can do this automatically for you.
Yeah my plasma accepts the 23.976 output from my Nvidia 570 GTX without problems.

And when I tried the 29.97 1080i video while using 23.976 in
desktop, the video was laggy when there was panning etc in
the video. Using 23.976 video in the 23.976 desktop the
result is super smooth and looks really awesome, expecially
with 1080p content. Good quality 23.976 720p also looks
great with 23.976 in the desktop.

The plasma is the LG 60PK550 (great set!).

maybe lavcuvid can do IVTC? I know it uses the hardware deinterlacing, and there is an IVTC checkbox in the Nvidia control panel. I don't know if it can tell automatically which content has been telecined, or if you can just force it, though.

IIRC when using TMT3 w/DXVA and playing 29.97 telecined content, I just had to set my card to 23p and it would do IVTC, but I'm not 100% sure, it's been a while.
I am not sure, the checkbox is checked but there is no "force"
choice anywhere. Simply put, these 1080i 29.97 movies are
annoying me when I watch them because of the added
stutter when the camera moves or sweeps across.

:thanks:

[Qaq]

Simply put, these 1080i 29.97 movies are annoying me when I watch them because of the added stutter when the camera moves or sweeps across.
I'm afraid it's not possible to fix it completely in real-time playback. See here: http://forum.doom9.org/showpost.php?p=1507421&postcount=99

[fairchild]

and they're giving away the obsolete ones now(the i1lt runs the exact same hardware as the i1d2): http://www.buy.com/prod/x-rite-eye-one-displaylt-color-management-solution/q/loc/101/205985210.html

This makes me sad as I paid $149 a couple of months back. :mad:

[Gleb Egorych]

There is a problem with exclusive fullscreen mode and Zoom feature in Zoom Player. When I try to zoom picture (Num+/Num-) in exclusive fullscreen mode ZP crashes with error in madVR.ax
Problem signature:
Problem Event Name: APPCRASH
Application Name: zplayer.exe
Application Version: 8.0.0.0
Application Timestamp: 2a425e19
Fault Module Name: madVR.ax
Fault Module Version: 0.65.0.0
Fault Module Timestamp: 4dee9614
Exception Code: c0000005
Exception Offset: 00005dfb
OS Version: 6.1.7601.2.1.0.256.1
Locale ID: 1049
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789
If I use zoom feature in windowed fullscreen mode then madVR fails to enter exclusive mode with scaled picture. Is it a known bug/limitation of madVR or ZP?

[Xaurus]

I'm afraid it's not possible to fix it completely in real-time playback. See here: http://forum.doom9.org/showpost.php?p=1507421&postcount=99
Thanks. I think I will go back to the 720p versions. I've been fiddling with different settings in LAVCuvid for a couple of hours now, but without real success.

[Qaq]

An idea:
madshi, how about special filter for FOTR green tint?
http://www.nerdsociety.com/unboxing-lotr-ee-bluray-green-tint-issue/
Peter Jackson has been asked several times through his FB about the issue but he hasn’t responded yet

[jmone]

That happens with me only on windowed mode. When it switches to exclusive it gets smooth. Going back to windowed stutters again, but sometimes it just gets fixed.

Mine is the other way around. Looks OK in Windowed Mode, Switches to Exclusive seems OK then it seems to present the Video Frames in the wrong order (and droped frames goes nuts). It may seem to settle down then off it would go again. Neither a pause/play or a seek will fix it. Only a STOP/Play. It is defiantly related to the refresh rate change that has just happened and I did not ever see this with the ATI card, so it is a combo of madVR, Refreshrate change, nvidia / LAV CUVID.

Thanks
Nathan

Edit - and of course it is not 100% consistent (that would be too easy) but it does happen frequently.

[e-t172]

Simply put, these 1080i 29.97 movies are annoying me when I watch them because of the added stutter when the camera moves or sweeps across.
I'm afraid it's not possible to fix it completely in real-time playback. See here: http://forum.doom9.org/showpost.php?p=1507421&postcount=99
Thanks. I think I will go back to the 720p versions. I've been fiddling with different settings in LAVCuvid for a couple of hours now, but without real success.

Have you tried my IVTC filter (http://forum.doom9.org/showpost.php?p=1505473&postcount=778)? In theory, it should generate constant and smooth frame durations.

[robpdotcom]

Have you tried my IVTC filter (http://forum.doom9.org/showpost.php?p=1505473&postcount=778)? In theory, it should generate constant and smooth frame durations.

I've been using it for a few weeks now, and it works very well. It actually did a better job on one particular file than DScaler or ATI's pulldown removal.

Having it in ffdshow makes it the most convenient solution for ATSC/NTSC material I've found so far - I set a shortcut on my universal remote to toggle deinterlacing in ffdshow, so I can switch between yadif and IVTC on the fly.:cool:

[madshi]

It actually did a better job on one particular file than DScaler or ATI's pulldown removal.
Can I have a sample of that file which shows the difference, please?

[e-t172]

I've been using it for a few weeks now, and it works very well. It actually did a better job on one particular file than DScaler or ATI's pulldown removal.

That's good to know, thanks :) Maybe I was a little too cautious with the "full of bugs, not suitable for everyday use" disclaimer...

[jmone]

I get a few "exclusive mode failed" msg with madVR in MC16. Once it occurs the only fix is to close and restart MC16. Any ideas of what causes this and how to avoid it?

[e-t172]

Having it in ffdshow makes it the most convenient solution for ATSC/NTSC material I've found so far - I set a shortcut on my universal remote to toggle deinterlacing in ffdshow, so I can switch between yadif and IVTC on the fly.:cool:

Technically, it should be possible to do this automatically. The filter could disable itself when it cannot "lock" into a reasonably suitable pattern position (which would occur if pattern positions are all over the place in the backward/forward batches), with a configurable threshold. But this needs someone to implement it...

[Mark_A_W]

I am unsure where to ask, but I recently acquired a few movies in a 1080i 29.97 fps format.

I am running 23.976 fps progressive videos without any problems,
fed directly to my plasma TV.

But this 1080i content proved to be hard to get right.
No matter what I did I could not get rid of "panning stutter".

So what is the best desktop resolution for 1080i content?

I tried 1080p / 29.97 but this had panning stutter, refresh
rate with CTRL+J was 29.97 so no problem here.

Then I tried 1080i / 29.97 and after checking CTRL+J with madvr the
screen was running at 59.94. The panning stutter was still present,
although perhaps slightly less obvious than on the previous resolution.

I am using mpc-hc, madvr, lavcuvid and lavfilters.
lavcuvid is set at 25/30 content.

:thanks:

Xaurus, have you tried the "unofficial 1080i IVTC version of Dscaler 5 decoder"? It's the only decoder that will perform IVTC on 1080i mpeg2 TS files.

[e-t172]

It's the only decoder that will perform IVTC on 1080i mpeg2 TS files.

No it's not... ;)

[Xaurus]

Thank you everyone for your suggestions. :)

I am kind of unsure about how to add these "custom"
deinterlacers, do I need to install ffdshow in order to use them?

Because right now I think my setup is very clean with only
madvr, lavfilters and lavcuvid. I had to install AC3filter in order
to output 2 channel pcm to my external DAC as well, though.

[robpdotcom]

Can I have a sample of that file which shows the difference, please?

It was a recorded TV show, which has since been deleted (I use my PC as my DVR). However, it is a weekly show, so I'll keep an eye on future episodes to see if results are the same.

EDIT: The same episode is being rerun this weekend. I'll record it again and get a sample from one of the more obvious trouble spots (there was one particular scene change where other decoders would consistently drop/repeat a frame).


That's good to know, thanks :) Maybe I was a little too cautious with the "full of bugs, not suitable for everyday use" disclaimer...

The only problem I really see with it is that audio will sometimes get out of sync after seeking (which is common since I'm skipping past advertisements) - a short seek backwards will almost always get it back in sync.


Technically, it should be possible to do this automatically. The filter could disable itself when it cannot "lock" into a reasonably suitable pattern position (which would occur if pattern positions are all over the place in the backward/forward batches), with a configurable threshold. But this needs someone to implement it...

I'm just happy that I don't need to switch decoders and reload the file. Pressing a button on my remote is a very small inconvenience.

[alph@]

and they're giving away the obsolete ones now(the i1lt runs the exact same hardware as the i1d2): http://www.buy.com/prod/x-rite-eye-one-displaylt-color-management-solution/q/loc/101/205985210.html

leepery, you have a Xrite lt, what do you think, I hesitate between a Xrite lt and colorhcfr,or a chroma 5 with chroma pure standard, ok it is not the same price range.

[Matching_Mole]

Have you tried my IVTC filter (http://forum.doom9.org/showpost.php?p=1505473&postcount=778)? In theory, it should generate constant and smooth frame durations.

Personally I tried it quickly and it give me better result than IVTC filters in Avisynth so far. I will try it more deeply during the next day but why this filter is currently not available in the standard version of FFDshow?

[e-t172]

The only problem I really see with it is that audio will sometimes get out of sync after seeking (which is common since I'm skipping past advertisements) - a short seek backwards will almost always get it back in sync.

That's weird. I know my filter is supposed to have bugs, but not this kind of bug. In theory it should always stay very close to the original frame timestamps; it cannot "deviate" from them. That may be caused by the heavy buffering the filter does though (which causes the playback to freeze briefly when you seek so it can buffer frames).

Personally I tried it quickly and it give me better result than IVTC filters in Avisynth so far. I will try it more deeply during the next day but why this filter is currently not available in the standard version of FFDshow?

Because I wrote this code 2 years ago and didn't finish it; in fact, I wouldn't even have released it if nevcairel hadn't brought up the subject of IVTC. So it's only a proof of concept and it's supposed to be full of bugs. The filter is designed to be better than everything else (there would not be much point otherwise), but I expected it to be too "annoying" for real, day to day viewing.

The reason why it's not integrated into ffdshow is that there's no maintainer for it. I don't have time to maintain it myself now, as I have other projects which take priority. I may be able to get back into it some day, but that won't be before at least several months. I'm hoping someone implements a real, well-maintained filter inspired from my work so it can be made into something "releasable".

I must admit, I'm really surprised to see that you're using this code without experiencing severe problems.

[noee]

I must admit, I'm really surprised to see that you're using this code without experiencing severe problems.
fwiw, I've been using it too, without any issues that I can tell (DVD NTSC sources only).

[xv]

Would it be possible to add additional matrices? Currently only BT.601 and BT.709 is supported. Please add the other matrices supported by H.264 too:
GBR:
R = Cr
G = Y
B = Cb

United States Federal Communications Commission Title 47 Code of Federal Regulations (2003) 73.682 (a) (20):
Kr = 0.3
Kb = 0.11

SMPTE240M:
Kr = 0.212
Kb = 0.087

YCgCo:
Cb -= 128
Cr -= 128
R = Y - Cb + Cr
G = Y + Cb
B = Y - Cb - Cr
For YCgCo see also: http://de.wikipedia.org/wiki/YCgCo-Farbmodell (no english version)
Maybe it could be possible to select the matrices you want to have in the Ctrl+Alt+Shift+M list in a settings dialog.

[cremor]

Hi all,

first, big thanks madshi for this great piece of software.

I just got a new LCD which makes watching movies on my PC finally enjoyable. Now I'd like to know what are the best madVR settings for that display.

It has a TN panel which (according to some reviews) accepts 8 bit color depth but can only display 6 bit. It uses dithering to get back to a (emulated) 8 bit output. Should I set it to 6 bit or 8 bit in madVR?

I have downloaded (and installed) a ICC profile which some other user has created (I don't have a meter to calibrate myself). As far as I understand all that, this ICC profile makes a best possible match to the sRGB color space. How should I configure madVR in the "calibration" and "color & gamma" pages based on that?