Author Topic: MLV App 1.11 - All in one MLV Video Post Processing App [Windows, Mac and Linux]  (Read 465740 times)

ilia3101

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If you wanna inlcude MLV App in compatrisons, set profile to sRGB and creative adjustments set to OFF (or you can keep them on and set dark strength slider to 0)

Fixing white balance:
Mlv app


Acr



Pretty impressed how alike this is now in both apps. Maybe only the 0.26 tag needs added to the dng now and it´s perfect?

I'd expect things to be similar, same matrices as Adobe.

And why is everyone so bothered by exposure? It's linear, so a compensation doesn't matter if you do it by hand, or if it's embedded in the file.

Dmytro_ua

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Fixing white balance:
Mlv app


Acr


I was always interested when the image is similar looking why the tint is so different (ACR vs MLVApp)?
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Danne

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I was always interested when the image is similar looking why the tint is so different (ACR vs MLVApp)?
Well, calibrating against acr among all creative color spaces, slider and so on in mlv app is probably not a quick fix ;).

masc

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Well, calibrating against acr among all creative color spaces, slider and so on in mlv app is probably not a quick fix ;).
Right. And I don't know why this should be necessary. We just know what we calculate, but we don't know what (exactly) Adobe or Resolve calculates... who knows about their cheating factors behind the GUI? Why should we calibrate to it? 8) If someone finds something wrong in our code and math, it is no problem to fix it.
Thanks for your examples - so far I am impressed how close we are. Thanks especially to Ilia for that nice processing!
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cmh

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And why is everyone so bothered by exposure? It's linear, so a compensation doesn't matter if you do it by hand, or if it's embedded in the file.

I'm not sure if you are asking how we came to talk about it or what are the technical reasons for those tests so I'll quickly glance over both so you don't have to search over the previous posts:

Context: Another ml user and I were sharing power grades involving cdng and bmdfilm and we both wondered why we had to raise the exposure by +2. He was afraid that it would increase noise. Doing some tests (checking highlight retentions with various MLVApp profiles) I realized that cdng exposure was always darker no matter the color space/gamut compared to encoded videos. Comparing ursa mini footage, the most obvious thing to pop up was an exif tag missing so I wanted to point this out.

Why it is relevant to me? If I mix Prores and cndg footage, I would only be able to correct cdng exposure. That's something to keep in mind before starting a grade.

That said, I don't care about ACR/Lightroom at all as it is not part of my workflow (I don't even understand why it matters but hey, if someone is asking for a test I'll gladly comply and it confirmed the missing tag). I found a discrepancy between prores and cdng. I don't care about a fix in MLVApp (exiftool does the job anyway) but I'm not the one qualified to say if it's a bug or a feature (that is up to you and your community to decide). Sometime those little bugs are the tree that hides the forest sometimes it's not worth fixing it for technical reason, I honestly have no idea. It's just an exif tag for cdng export.

edit: added MLVapp screenshot in a previous post as requested.
Also there's a lot of misconceptions around bmdfilm (in Resolve's raw tab, Gen1 is actually not a transform) but I won't go into there as this is not directly relevant to MLVApp (but if the option is present in MLVApp, people should be able to use it and expect a decent result).

Kharak

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If you import dng’s in to Resolve, it all depends on your color management.

What your input is set to, what output you have. Log-c output can rarely handle a +2 exposure without introducing a lot of noise and clipping, bmdfilm has always been a very dark log. That is why I think its not a good idea to universally set the exposure to +2. But manually setting an exposure, sure, the more options the better.

For compressed output like h264, prores etc, I can see it can be a problem.

I personally adjust the exposure individually on all clips in resolve.
once you go raw you never go back

cmh

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Well that's why I'm comparing apples to apples: MLVApp prores sRGB/rec709 compared to MLVApp cdng in Resolve with sRGB/rec709 in the Raw tab (but also other color spaces/gamma).
If you raise the exposure by +1.25 or 1.26 (or fix it in the tag with exiftool), you get pretty much the same picture (there's still -15 tint difference for some reasons, that's not the point tho).

I don't really want to talk about bmdfilm but it's more complicated than that (the raw tab is different between legit blackmagic files and other cdng).

Also I'll stop answering if a comment is ignoring the previous posts and just assume that I did something wrong. No offense.

edit: no adjustements made (other than + 1.25 exposure and wb in the raw tab), pretone curve disabled, default DaVinci YRGB.

masc

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Also I'll stop answering if a comment is ignoring the previous posts and just assume that I did something wrong.
Atm nobody can tell where the issue really is. Nodoby assumes, you did something wrong.
DNG was invented by Adobe. So if it looks more or less correct there, but not in other Apps like Resolve, it is even harder to say that something in the DNG is wrong.
Someone tried converting a CR2 to DNG with ACR (if there is a program doing it right, then ACR) and opened this in Resolve and Lightroom? Is there also a difference visible?
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cmh

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Atm nobody can tell where the issue really is. Nodoby assumes, you did something wrong.
Care to elaborate? Can you suggest a way to accurately do a comparison between the two?
edit: nvm, it doesn't matter.

Danne

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I think it's more like narrow down the exact issue now. Build a case and add clear comparisons of what the issue really is. Resolve, mlv app, metadata? A quick "fix" with exiftool might at first glance seem to be legit but might not be best practice when working other apps for instance. Done properly it's probably a good learning experience involved here.

cmh

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Well it's like you said Danne, if adobe's DNG is the standard, then passing out the Baseline exposure (+0.26) to the cinemadng exported file gets you closer to said standard.
I totally understand that Blackmagic's Resolve cinemadng rendition isn't the standard, they have added extensions to cinemadng since the ursa mini late 2014 for exemple.
I don't mind the dismissive answers but some comparisons with the exact same settings with another NLE like Premiere instead of ACR are still lacking.
I'm probably not the only one having that issue:
https://forum.blackmagicdesign.com/viewtopic.php?t=45045

In the meantime, I'll be comparing the advantages between cdng in Resolve to tonemapped prores from MLVApp in terms of highlight retention.
I'm still wondering if there's an advantage to get blackmagic's extensions to work on MLVApp's cdng. Something I'll check later.

edit: those blackmagic's extensions, it's just the UniqueCameraModel tag that matters, change it to any blackmagic model and you'll get the full raw tab in Resolve as you would with one of their camera.

Danne

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All numbers and statements above are still assumptions(didn't check your link).
Dismissive or not. Clear facts and robust figures and comparisons would help things forward. Right now, it's a pretty mess ;).

ilia3101

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I was always interested when the image is similar looking why the tint is so different (ACR vs MLVApp)?

I think this may be because MLV App uses the blackbody curve, not daylight curve (my laziness). But it doesn't matter much. Temperature and tint are just a sorta stupid coordinate system, and if you can put them in the right place you will get the right result.

Danne

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I'm probably not the only one having that issue:
https://forum.blackmagicdesign.com/viewtopic.php?t=45045
Checked your link. Pretty much verifies the issue lies within resolve.

cmh

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Definitely. Even if there's a slight difference between Adobe Camera RAW and MLVApp, let's say the quarter exposure thing, Resolve is still a stop below.
edit: but the fact that some people here doesn't find that result with Resolve is pretty intriguing nonetheless...

ilia3101

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@cmh thanks for the explanation

Also there's a lot of misconceptions around bmdfilm (in Resolve's raw tab, Gen1 is actually not a transform) but I won't go into there as this is not directly relevant to MLVApp

Is Gen1 what's used by the original pocket and 2.5k cinema camera? And what does "not a trasnsform" mean in this context?

but if the option is present in MLVApp, people should be able to use it and expect a decent result.

I agree it is an awful option in MLV App, as there is no technical information about BMDFilm anywhere, like expressions for the log curve, or matrices for the gamut (which seems to be different on every camera that shoots it).

cmh

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You're welcome.
You'll understand this better than me:
https://forum.blackmagicdesign.com/viewtopic.php?f=2&t=87576

CaptainHook at Blackmagic Design talking about Gen 1
Quote
Blackmagic Film" for Gen 1 is actually not a transform but passes out sensor space, or sensor RGB. You can basically think of it as "no colour science applied". So you would need a transform from that particular sensors response to the gamut of your choice which you'd need to get from that manufacturer. I believe Digital Bolex for example offered LUTs to transform from their sensor RGB to common gamuts like 709 via a LUT to be used in this workflow with DNGs in Resolve.

Now to he talks about Gen 4 which is a different beast:
Quote
Blackmagic Design Wide Gamut Gen 4 is a common gamut with defined primaries that all our cameras can use (with raw files in Resolve you can choose Gen 4 for all our raw capable cameras). So that is why you can use "Blackmagic Design Broadcast Film" or "Blackmagic Design Pocket 4K Film" colour space/gamut interchangeably as John Paines points out since both of those cameras shipped with Gen 4 - but ideally these options will be consolidated to "Blackmagic Design Wide Gamut Gen 4" for colour space/gamut throughout Resolve.

A member who tried to import Sony shots, Jacob Fenn at the end of the convo
Quote
My issue ended up most likely being that the DNG's weren't relaying the ISO data needed for Resolve to properly debayer to Blackmagic's log curve. Therefore, when I'd apply what I thought was a normalizing transform via a CST node, the result was off because that CST node expects ISO 800. Thanks CaptainHook for help figuring that out.

The ISO data he's refering to isn't what he's talking about really, nor the "debayer to Blackmagic's log curve" he's babbling about. We can totally change the UniqueCameraModel tag for a blackmagic camera and access those ISO settings in the raw tab (spoiler: it's pretty useless for exposure but you can access any blackmagic Gamut/Color Space like the Blackmagic Design Wide Gamut Gen 4 for exemple).

It is probably the BaselineExposure exif tag, I compared with Ursa mini cdng and it can only be this one, but I think I already made this clear.

I agree it is an awful option in MLV App, as there is no technical information about BMDFilm anywhere, like expressions for the log curve, or matrices for the gamut (which seems to be different on every camera that shoots it).

I don't really want to give an opinion but if you don't deem it accurate or reliable well...

CaptainHook talking about clipping, just to hammer the previous argument that using bmdfilm (or any other gammut/colorspace; appart from linear that I can conceive for streamlined SFX workflow) in the raw tab is useless; using rec709 and a CST to your fav log as a first node is as good.
Quote
Yes, DNGs in the metadata provide the matrices and AsShotNeutral tags needed to convert from XYZ to SensorRGB (and back) as supplied by the camera manufacturer so Resolve will be converting from SensorRGB -> XYZ -> Rec709. As for getting an XYZ output option I'm not part of the Resolve team so you would have better luck requesting that direct to them, but you could use CST to go from Rec709 primaries to any other gamut as the output from the RAW decode should not be clipped.

Then maybe I misunderstood.
Also, sorry for the non MLVApp related stuff.

cmh

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Also keep in mind that the bmdfilm profile from MLVApp is totally fine, you can keep it but this is not what people do, they export to cdng and use bmdfilm in the raw tab which gives horrible colors and worst than that, they sometimes use Gen 3 or Gen 4 to rec709 as a final CST node and start grading (and this is the reason why I don't want to talk about this and made my comparisons only with rec709, without tonemapping in Resolve or MLVApp, it's complicated enough).
Let me take a screenshot real quick.
Left is cdng with bmdfilm in the raw tab and a CST to bmdfilm Gen1 to rec709. Right is prores with MLVApp's bmdfilm and the same CST to bmdfilm Gen1 to rec709

This is ungraded, just the +1.25 exposure thing and a +15 tint for the cdng clips (this is common even across other colorspace/gamma settings given the appropriate CST ofc, in a sense that if I take the same screenshot with cdng with rec709 in the raw tab +1.25 exposure +15 tint vs prores with the MLVApp's rec709 profile or let's say cdng with linear in the raw tab +1.25 exposure +15 tint with a CST node to rec709 vs prores with the MLVApp's linear profile with a CST node to rec709 in Resolve, you wouldn't be able to tell where's the line, is that clear, I'm not sure).

MLVApp's bmdfilm profile is not a problem, if I compare a rec709 footage from mlvapp (no tonemapping just the plain rec709 profile) and compare it to a prores with the bmdfilm profile and apply a CST from Gen 1 to rec 709 in Resolve, it's close-ish (a little more vibrant and a slight gamma difference but that's to be expected, I guess you got the matrices made for another NLE than Resolve so the right one, maybe people on acescentral can help, idk).

edit: On an another subject, I also tested AsShotNeutral values that I derived from a CR2 I took with my camera on a cdng, thinking that it might be the cause for the +15 tint and just ended up with totally wrong white balance value in Resolve's raw tab, so that's not that but you all probably knew.

reddeercity

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No problems here , on x64 win7pro ,
take this with a gain of salt , not knowing if you know about this.
Looking like a color space (gamma curve) problem
e.g. 1.8-2.6
https://www.eizo.be/en/knowledge/monitor-expertise/gamma-values-of-lcd-monitors/
Quote
Gamma characteristics are represented by the equation y = xγ.
At the ideal gamma value of 1.0, y = x; but since each monitor has its own unique gamma characteristics (gamma values), y generally doesn't equal x.
The above graph depicts a curve adjusted to the standard Windows gamma value of 2.2. The standard gamma value for the Mac OS is 1.8.

my 2cents  :D

Danne

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edit: On an another subject, I also tested AsShotNeutral values that I derived from a CR2 I took with my camera on a cdng, thinking that it might be the cause for the +15 tint and just ended up with totally wrong white balance value in Resolve's raw tab, so that's not that but you all probably knew.
AsShotNeutral as well as Baseline Exposure tag are simply information about white balance and exposure. Since it´s raw you can simply set them both in your nle. They will do no magic if changed with exiftool.


Another take on this "issue". Let´s compare a dng(raw) from all three nle.

First Davinci resolve(notice the lack of applied tone curve?) Actually a good thing letting the user decide manually or by setting a tab option:


Adobe camera raw. Exposure seems the same but tone curve added under the hood


Mlv App Tangent - rec709. Most similar look I could get exposure wise and tone curve wise. Wb will obviously differ slightly. It´s off anyway


Back to resolve. How about that tone curve. Well look. You can apply it here as well:


Now check resolve output again. Almost identical to acr and mlv app. Actually resolve and mlv app match better in wb now.


Conclusion:
Use Tangent - rec709 in mlv app for proxies. In resolve apply the tone curve per above.


Edit: What is this "Tangent" Tonemapping Function anyway? Never heard of it but it seems spot on here. Checking code:
Code: [Select]
    { /* PROFILE_FILM */
        .allow_creative_adjustments = 1,
        .tonemap_function = TONEMAP_Tangent,
        .gamma_power = 3.465,
        .colour_gamut = GAMUT_Rec709
    },

cmh

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Unfortunately I don't have any other monitor to test and it's a cheap 6 bit + frc ( probably like all of us who did those tests). There's no color profile used on windows.


@danne
For the tonemapping settings as I stated, I tested everything in rec709 for consistency.
Rec709 profile on MlVApp without creative adjustment, so no tonemapping.
Rec 709 in resolved raw tab with no Luma tonemapping of a CST, precurve tone disabled.
 
But yeah, apparently ACR is doing things under the hood.

Edit: my bad reddeercity you were talking about the gamma curve of the OS, yeah worth investigating. Sorry I literally just woke up.

ilia3101

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@cmh thanks again for all the interesting info. Confirms what I thought of the original BMPCC and BMCC, and why everyone seemed to get awful results with them.

Also good to know about Gen4 using same primaries on all cameras (still annoying they don't seem to tell use what they are, though I haven't checked onthis subject for a while).

I wonder what Gen2 and Gen3 are like...

Also, sorry for the non MLVApp related stuff.

Absolutely fine, it is very related and useful I think, as we have "BMDFilm"


I can't read through everything you sent yet, will have a more detailed look in a few hours.



@Danne Tangent tonemap was just 2017 me realising that arctan(x)/(pi/2) worked for highlight roll off :)


Danne

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@danne
For the tonemapping settings as I stated, I tested everything in rec709 for consistency.
Rec709 profile on MlVApp without creative adjustment, so no tonemapping.
Rec 709 in resolved raw tab with no Luma tonemapping of a CST, precurve tone disabled.
It´s all rec709 in resolve as well. If you refer to mlv app you cannot expect coherent results without tweaking. There is nothing wrong with baseline exposure. The problem is related to interpretations coming from mlv app. The fix is not modifiying metadata. It´s to tweak and match input/output in mlv app.

cmh

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@danne I don't want to be a contrarian but if you don't change anything appart from using the rec709 profile on MLVApp and export to prores as is. You'll get an accurate rec709 conform footage to compare to (not esthetically pleasing sure, that's besides the point).
Edit : on phone: expect some typos.

Same goes for the srbg profile. super accurate, perfectly conform. Ilia should confirm my claims ofc.

Edit: just saying, the pretone curve thing in Resolve is there for historical reasons, that was used in old resolve by default but it will clip your footage like any pretone curve. There's also other mapping ofx in resolve, like in color space transform for example.

Fun fact (maybe) You can also download filmic aka tangent, Reinhard or Corona's tonemaping functions for Resolve's Fusion tab/og Fusion, but you better transform in linear before, same algorithm as MlVApp but tweakable.I should stop there, since it's irrelevant.

cmh

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I feel like if people would really put an effort into what I suggested in the first place, we might understand each others. MlVApp's prores footage with only the rec709 profile applied vs cdng (not an extracted frame) in resolve with rec709 color space/gamma in the raw tab. Every other comparisons are muddying the water. I didn't made any other claim, ACR was only useful to understand the dng tag. If we can all agree on this part then we could move on.

Edit: yes I understand Adobe created the dng format from Tiff, yadi yada, but it's a spec (like the headers, the legal exif tags etc) not the rendition. As controversial as it sounds, It really is a weird metric when it comes to how it should look in MLVApp (well with the inclusion of raw2mlv it makes more sense, I'll reckon). I'm eager to see what would be the result in Premiere.