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[jmone]

I'm having a bit of a play with the new JRVR Features and it seems well laid out.  One area I'm not sure about is what features apply when across various media playback.  For example, in checking out the use of ICC/ICM profiles, it appears they are used:
- On all media when HDR Passthrough is unchecked
- On SDR media when HDR Passthrough is checked
- Not on HDR media when HDR Passthrough is checked

I get the impression above from the JRVR OSD when playing content (as there is a line saying it is using ICC/3DLUT processing or not).  I'm not sure it would be easy (unless colour coded) to do in the JRVR Setup Menu but maybe another way?

[Hendrik]

ICC profiles cannot be applied to HDR content right now, and not sure if that can change.
3DLUTs can be applied to HDR content if you use a HDR 3DLUT. This is something I'll add support for with a secondary 3DLUT option in the future.

I suppose an additional note on the options page detailing these limitations makes sense.

PS:
With "HDR Content" I mean HDR output. At that point it doesn't matter what the content originally was, if it was tonemapped to SDR, then its SDR, as the calibration runs almost last in the processing.

[jmone]

With "HDR Content" I mean HDR output. At that point it doesn't matter what the content originally was, if it was tonemapped to SDR, then its SDR, as the calibration runs almost last in the processing.

Ahhh, this is the bit I was confused on.  I was thinking HDR vs SDR Content, not HDR vs SDR Output.  But makes sense now you mention it.

I think my confusion is how some of the options are grouped and what option applies when.  Would it make sense to reorg this page a bit, along the lines of the following where all related sub options are grouped together?

Code: [Select]

[] Enable HDR to SDR Tonemapping (else HDR Passthrough will be applied & these options are greyed out if the check box is not enabled)
....
....

v Display Calibration Settings for SD Output
....
....

v Display Calibration Settings for HDR Output (even if it marked as not yet supported)
....
....

v Advanced (options that apply regardless of the settings above)
....
....
I know the above is not right, but it is really about grouping:
1) If you want to do HDR to SDR Tonemapping and if so, then all the various options for that
2) All the calibration options when outputting SDR and separately HDR (as I take it they can be different)
3) General Stuff that applies regardless

[Hendrik]

You can't really opt-out of tonemapping, because pass-through is only available if the display supports it as well, so its very well possible that tonemapping is going to be used no matter what options you set, because it couldn't do HDR output. The options are not really in a position to determine that either.

Calibration is also not really affected by that choice, because even if HDR Pass-through is working, you can still play SDR videos.

I suppose it could make sense to entirely separate Calibration for HDR output in its own section, as the gamut/gamma options also don't apply to it (which isn't as much separating, but renaming the Calibration group, since HDR is not even in there yet). The HDR section could also be disabled if HDR pass-through is disabled, as in that direction it ensures that it'll never be used.

[jmone]

Slowly getting it!

- I was coming from a POV that as all my screens do accept HDR, I'm first choosing on which ones I want to tonemap.... and then once making that decision.... what options I then need to think about setting (but I get your point that many will only have SDR screen so Tonemapping is a must if you have HDR Content).  I guess if JRVR is unable to determine from the OS if HDR Support is even supported by the display then the top "HDR" part makes sense as it is

- Renaming "Calibration" to "Calibration for SDR Output" (or making a note) clears that part up

- Also, your previous explanation on the Calibration being based on HDR vs SDR output (not HDR vs SDR content) is what made me then question if the option under Advanced options (Gamut Mapping Mode, HDR Overlay Brightness, HDR Dynamic Peak Detection etc) always apply and if not under what conditions (HDR vs SDR Source, and/or HDR vs SDR Output).

[jmone]

Other features that may be worth adding a note explaining the options for users are:
- Scaling/Upscaling/Algorithm (are they listed in order of "quality/performance")
- Scaling/Scale in Sigmoidal Light
- Scaling/Advanced Scaling/Chroma
- Scaling/Downscaling/Algorithm (are they listed in order of "quality/performance")

[Hendrik]

The advanced options are advanced for a reason.

Gamut Mapping Mode applies whenever the Gamut (eg. colorspace) of a video needs to be reduced. The most common situation for this is HDR tonemaping (eg. BT.2020 or DCI-P3) to SDR (eg. BT.709), but its not exclusively for this. You could have SDR BT.2020 videos, even if they are rare. ("tonemapping" is the process of reducing the brightness from HDR to SDR, gamut mapping is reducing the wider color space)

HDR Overlay Brightness applies when SDR overlays get shown on top of HDR pass-through video - eg. subtitles. I'm thinking about removing this option again, it was primarily added for myself to experiment with different values and how they look.

Convert HLG to HDR 10 should be clear, it even says pass-through in the name.

And Peak Detect is for tonemapping, of course.

I can of course rename any of the options to make them a bit clearer.

[marko]

I've said before that I try to read and follow the development, but it might as well be written in swahili for me, I just don't understand all the moving parts and their acronyms. I figured that dev work was pretty well on at this point, and Nathan is full of enthusiasm, so, why not eh?

Ultimately, this would get most use on the HTPC, outputting to a five year old LG TV that switches to HDR when the PC fires up (I see a little "HDR" in the top right corner for a few seconds).

I tested on the main PC, which uses a Dell monitor. Everything JRVR and MadVR is at default.

Why is the JRVR screencap much less bright than the MadVR one?

[Hendrik]

The most likely explanation is that you are watching a HDR movie, and the tonemapping just isn't identical. You can tune the brightness target in the settings if you want. Check "Tonemapping Target Peak Nits" in the Output Device settings under JRVR. Lower peak nits make the image brighter. 203 is "reference" level according to some specifications, but older specifications had 120 for that, so maybe try something along those lines.

HDR Tonemapping is very much an area actively in flux in any renderer, because there isn't just one approach you can use, and you basically need to factor in information about the screen its going to be shown on, as well as the preferences of the user to a degree, so "out of the box" it'll never be identical between two independent components or players.

If this wasn't a HDR file, baring any misconfiguration, the other possibility is that your screen actually has an active calibration profile from its driver, which madVR doesn't use. You can disable its use in the JRVR Output settings under Calibration -> Calibration Method.

We might have more information if you take a screenshot of JRVR with the Info OSD up (Ctrl-J).

[marko]

I think the file might be HDR. I will give it a bash on the htpc, and try and get screenies with the ctrl+j stuff showing.

Trust me, none of this computes for me, so, when you mentioned "nits", my first thought was, "why not call the setting 'adjust brightness'", or is it not really as simple as that?

Technically challenged users like me could probably appreciate a set of dumbed down sliders that use plain English labels that would help us to make some adjustments, however course they may be.

Just thinking out loud is all. Will be the weekend at earliest before I can get the screenies.

[jmone]

203 Nits:  I'm not sure what role it plays with overall content output (if at all), but it is certainly used when grading clips mixed SDR and HDR clips in a HDR movie.  From the Davici Resolve manual:

....support for remapping SDR content to HDR by mapping 100 nits to 203 nits (defined as the diffuse white level) according to the BT.2100 recommendation. This enables the peak highlights of SDR material to compete more favorably against the significantly brighter highlights of HDR content in programs that combine both (such as documentaries), so that SDR whites continue to appear white, rather than gray, when compared to diffuse white in HDR.

FYI - I do this on my HDR output but find at times it makes some SDR clips over exposed.

[Hendrik]

I wonder if having a toggle for an "advanced mode" makes sense to have. Its a concept a lot of software has, where there is a basic set of settings, easy to understand, eg. with a simple slider, but if you go to advanced mode, the slider might turn into the input box for more freeform control, as well as some additional options show up.

As far as I know, its not something MC uses, but it might make sense here to offer both an easy as well as a precise setting for some options.

I'm not sure how else to eg. turn the brightness/nits option into a user-friendly slider while also letting advanced users retain the control we've had so far.
An alternate thought would be that instead of a slider it could be a dropdown box with a final "custom" option at the bottom that then shows the input box, maybe? So we just have some pre-defined options say from 80 to 400 in some useful steps? Not sure thats not too much for a drop down though. (eg. 80, 100, 120, 150, 180, 200/3, 250, 300, 400? already 9 options, but not that much granularity, a slider could represent that much better)

PS:
The problem with the 203 nits is that its designed for mixed content basically running in HDR mode, on screens that actually deliver the 200 nits if asked. Actual SDR screens are often a bit dimmer, so a value of 120 or such makes them look more as expected. Finding a default that works for everyone is impossible though. But maybe using a bit lower default fits more people?

[JimH]

I wonder if having a toggle for an "advanced mode" makes sense to have.

Good idea.

[jmone]

Just trying to follow-up on your request to review how well the layout and description makes makes sense to the std user.  Marco's comments could be a good example where it is Swahili to many. 

While I can get Tonemapping and Gamut Mapping to make various commercial HDR / SDR content look "good" on a wide range of consumer SDR / HDR displays, the bit I've stumbled on when reviewing was knowing which options apply when, and the interplay of the options. 

Adding some of the descriptions you posted above may be all that is needed on these options (does MC support hover over tool tips?)

[Hendrik]

I'm not too concerned about the advanced options, we can certainly reword them a bit, but overall its not super crucial, most people wouldn't want to touch them.

I'll definitely try to clarify the Calibration for SDR/HDR a bit, and try to make Tonemapping easier to understand.

Scaling is a complicated topic, and its also not as simple as "further down is better", while mostly true, it is subjective as well, especially around the middle. I also wouldn't know how to explain Sigmoidal scaling in a short sentence.

But if we go with having an "advanced mode" for the options, I could certainly simplify the default view by hiding those options that I didn't want to create a separate advanced section for in the first place. For example, I don't think anyone should be turning off sigmoidal scaling if they don't know what it is without me explaining it to them.

[JimH]

Nadhani tuko kwenye njia sahihi hapa.

[jmone]

Sounds good to me.  Having the options is great, setting them to a considered default is even better, trying to group and explain them and their interplay is (for me) hard.

I'm trying to look at the grouping in a few discrete areas areas that will make sense to users and which ones are the core variables that a user will initially need to set to get a "good" result, leaving the tweaking to later to get a "great" result. 

Displays:  Probably the biggest unknown that a user will need to define as JRVR needs to know
  - HDR Compatible?  and if so, do you want to use HDR mode?  (my PJ will take a HDR Signal but I want to tome map it, but my bright OLED I want to leave in HDR Passthrough)
  - How bright is the display AND how bright do you want to drive the display aka Bright vs Dark Room

These will really influence all the Gamut and Tonemapping options.

GPU Performance  The capability of the GPU will really impact the performance options for scaling & refining etc without dropping frames.  (almost like the Low/Med/High options for madVR).

[jmone]

Nadhani tuko kwenye njia sahihi hapa.

[terrym@tassie]

Nadhani tuko kwenye njia sahihi hapa.

Lakini machimbo hayo yanaweza kubaki kuwa magumu...

[JimH]

Mara nyingi haiwezekani

[terrym@tassie]

Mara nyingi haiwezekani

Sic verum est!   I think I may be getting 'Lost in Translation'....

[JimH]

e pluribus unum

[comox]

I'm with marko on not understanding any of this.

Please get the defaults right because that's all I'll ever use.

[rec head]

The idea of a beginner mode and an advanced options is good.

I think in Beginner Mode it might be easier to understand if the options were question based:
-- Does your TV support HDR?
---Do you want your TV to handle the HDR or do you want JRVR to do it?
------ (Note: if you select JRVR the "HDR" tag won't show up on your screen but does not mean that you are not getting the HDR experience. It means that JRVR is taking care of the HDR processing. This may be beneficial on older HDR TVs or projectors that don't fully support HDR)

etc.



I'm sure that I misrepresented things but I hope I made my point.