madVR - high quality video renderer (GPU assisted)

[VBB]

The other night I was messing with decoder settings, among other things. By changing everything except HEVC from "D3D11 native" to "None", and then enabling black bar cropping, I was able to get substantial performance improvements (8-10ms). Surprised me for sure, since my CPU is ancient (Core i7-920 from 2008). What really threw me off was that even without cropping, using CPU instead of GPU (GTX 960) was about 2ms faster.

[el Filou]

I've always been convinced there were issues with how madVR interacted with copyback decoding, seeing as every individual rendering step takes a hit in the stats in copyback when performance is decoding-limited due to an old system, look at this for example: https://forum.doom9.org/showthread.p...09#post1885609
The performance impact is not just on the decoding part. Feels like copyback hangs some paths in the GPU (it's not the PCIe bus), and if the system is limiting copyback speed then this impacts other rendering tasks.

[huhn]

the problem is these issues are very inconsistent between machines i have had system that didn't care at "all" about copyback. i needed very specific setup to show any different on that system and zen 2 on the other hand goes totally nuts and it works like a handbrake the last time i tested it this includes both nvidia and AMD gpus.

in my personal experience the difference is shown in the first renderstep and the last. so even the first super XBR chroma scale steps shows something like 3ms+ on my zen 2 with copyback and with native the usually ~0.3 same for the interop. it is like it waiting multiply MS to even start rendering.

[QBhd]

Not sure why anyone with a Zen 2 CPU would want or need to use hardware decoding... I am a firm believer in software decoding and if my ancient FX-8350 could just barely do HEVC 4K why wrestle with HW decoding?

QB

[LordX2]

Ok, I switched to copyback by selecting my card under D3D11.

I was able to play with quality settings, and it seems my max setting for Chroma upscaling is NGU Medium Anti-Aliasing.

Same with image upscaling - NGU Medium AA.

**Can I assume that any level of NGU is better than the default?**

These settings give a max of 62% GPU Load, with 3.2Gb of Video ram (out of 4) being used. So anything higher I feel would be pushing it for smooth playback.

Also, I noticed an odd thing while watching a 1080p clip - it showed two chromas. One that showed NGU, and the other showed Bicubic60 I believe. Why two chroma values on the info? Was that part of the 'let madvr decide' options under NGU settings?

[Asmodian]

NGU low is somewhat debatable in my opinion, but medium and above are quite good.

Different levels of NGU do not impact memory use much, but the GPU buffer size does change memory use a lot. If you want to decrease memory use lowering the GPU buffers to 6 or even lower usually has no downside (six is plenty to always have a frame ready).

You might also disable most trade quality for performance options. However, I recommend leaving "don't rerender frame when fade in/out is detected" and "scale chroma separately, if it saves performance" enabled.

Yes, the second one is controlled by the chroma option under algorithm quality. Chroma is stored at half the resolution of the luma so it needs scaling twice. The first scaling is much more important, and is set by chroma upscaling, so using NGU med for the first one and Bicubic for the second makes a lot of sense. You also want to put the most effort into the luma quality so madVR automatically picks a reasonable chroma option given the luma option.

[LordX2]

Originally Posted by Asmodian

NGU low is somewhat debatable in my opinion, but medium and above are quite good.

Different levels of NGU do not impact memory use much, but the GPU buffer size does change memory use a lot. If you want to decrease memory use lowering the GPU buffers to 6 or even lower usually has no downside (six is plenty to always have a frame ready).

You might also disable most trade quality for performance options. However, I recommend leaving "don't rerender frame when fade in/out is detected" and "scale chroma separately, if it saves performance" enabled.

Yes, the second one is controlled by the chroma option under algorithm quality. Chroma is stored at half the resolution of the luma so it needs scaling twice. The first scaling is much more important, and is set by chroma upscaling, so using NGU med for the first one and Bicubic for the second makes a lot of sense. You also want to put the most effort into the luma quality so madVR automatically picks a reasonable chroma option given the luma option.

Thank you for the detailed response!

I watched a 2 hour movie, with no pauses, and by the end it showed just two frame drops, and 1 glitch... I never noticed the glitch, however, I did get up to pee.

I don't really care if it records a glitch as long as I can't SEE it stutter on the screen. But the quality looks so damn good this way, I may just have to live with a little stutter here and there. (That will be my 'sacrifice' for quality!)

What are your reasons for: "However, I recommend leaving "don't rerender frame when fade in/out is detected" and "scale chroma separately, if it saves performance" enabled."

Going to go watch another movie right now (I am nuts) - will update if anything crazy happens - otherwise, thank you everyone for the tips!

[LordX2]

Which NGU should I choose?

For Chroma, and for upscaling?

Saw a 'guide' saying to use Anti-aliasing for Chroma, but Sharp for upscaling. I am currently set to anti-aliasing for both.

Thoughts?

[QBhd]

I am a fan of NGU sharp for everything... this really boils down to personal preference...

QB

[LordX2]

Originally Posted by QBhd

I am a fan of NGU sharp for everything... this really boils down to personal preference...

QB

Are the medium settings between the different NGU's the same stress on the GPU?

E.g. is NGU Anti-aliasing Medium going to pull the same amount of GPU power as NGU Sharp Medium? Given that all the other settings under are set to 'let madvr decide'.

Or is one more intense than another?

[Asmodian]

They are the same.

Originally Posted by LordX2

What are your reasons for: "However, I recommend leaving "don't rerender frame when fade in/out is detected" and "scale chroma separately, if it saves performance" enabled."

fade in/out deletes a bunch (5) rendered frames from the queue and rerenders them as fast as possible. This often causes glitches.

Scale chroma separately is good because it isn't really lower quality and can save a huge amount of performance, especially when watching 4K at <4K or 8K at 4K.

Originally Posted by LordX2

Which NGU should I choose?

I am a big fan of NGU AA. I always use NGU AA for chroma myself and often use NGU AA for everything. NGU Sharp is also nice and which I think looks best seems to depend on both the source and screen. NGU AA always looks good and while the extra sharpness from NGU Sharp is usually very nice I do notice it look unnatural with some sources.

I think if your pixels are totally invisible the downsides of NGU Sharp are less noticeable while if your pixels are pretty big NGU AA has a more natural look. I am not sure how others feel about this rule of thumb though, it does seem to be mostly preference. Most people do gravitate to NGU AA or NGU Sharp though.

[SamuriHL]

I'm firmly in the ngu AA chroma ngu sharp luma camp myself. Everything I watch is either native 4k or upscaled to 4k. I've not seen too many issues with sharp being overcooked thankfully.

Sent from my SM-G975U using Tapatalk

[LordX2]

Ok, updated and played around - landed at:

Chroma - NGU AA HIGH

Luma - NGU Sharp HIGH

The high mark is pushing it for me. Almost completely saturating my GTX 1650 Super. Chroma with Sharp High peaked at 96%, Chroma with AA High peaked at 92%.

I watched the end of avenger endgame as a test - with so much non stop action and SO many characters on the screen at one time, I figured it was a good test to see if there were any lags created by the video card working so hard.

Played through that scene with no officially frame drops or glitches, and no visible micro stutters! So it looks like I have found the theoretical MAX for my system. And at least I know I can drop those NGU's down to medium if I do run into a video that has lag/chop to it.

[Siso]

I wouldn't use NGU High for chroma.

[Asmodian]

I like NGU AA high for chroma..

But I would drop chroma to medium before changing luma.

[SamuriHL]

I'm with Asmodian. I use NGU AA High for chroma, as well. Well, depending on the profile. My 2070 doesn't like it for 720p upscaling. But for 1080p and 4K, definitely.

[LordX2]

Thank you for the input! I will change Chroma down to medium first if I run into a file with lag or problems.

As for HDR - the peak NITS setting is defaulted at 200. Should I set this to match the peak output of the projector? Which is roughly 125 at the distance I have it?

[Asmodian]

Theoretically yes, but feel free to use it to adjust the midrange brightness. Lower is brighter but will have less highlight detail.

[Alexkral]

I have noticed that the choice of upscaling for chroma affects the saturation very slightly, so maybe that's the reason why NGU AA looks more natural, because it doesn't look very saturated, but I think that using it the result is less saturated than the source. The differences are minimal anyway, and the end result will obviously still depend on the saturation settings.

@ LordX2

Yes, start testing with 125, but I think that projectors sometimes need values below 100, the latest betas allow them.

[QBhd]

Originally Posted by Siso

I wouldn't use NGU High for chroma.

LOL... for my 1080p==>4k I use Very High :P

It does drop down to High for 4K content though

QB