Some thoughts on the 'bogus' single-layer ('profile 5') Dolby Vision made by third party tools

[TobyX]

First of all, I was not sure about where to post this. After reading all the “abaut the…”-intros in all topics. Please forgive me if you (mods) would like to see it elsewhere.

The background of my posting are some discussions with (mainly) @KCX , @crazydave80, @TeknoJunky, @RosaVanWinkle, and some other guys in different threads at this forum.
E.g.:

Feature request: Support profile 7 Dolby Vision ('dual-layer DV') in MP4s

First of all (especially to the mods): please read this topic carefully befor closing it (as a similiar topic was closed by one mod without any reasonable reason). Thank you Second, for a better understanding, in the following, I will use terms like ‘single-’ vs. ‘dual-layer’ Dolby Vision (instead of the more uncommon tems profile 5 vs. profile 7 DV, respectively). Some points before I start with some details about the present request There is currently a discussion in another …

as well as here:

Dolby Vision not working on 7.24 with single layer mp4 files

First short tests show me that the DVDFab SL DV looks exactly like DL. In principle, everyone can check this themselves, even with a bad camera like mine. Find a spot from the video and make the comparison … For example, I looked for the spot on the Dolby Vision demo disc where the DV black is demonstrated. You can see that the point is much too bright with HDR10 and the screen is not darkened as with DV. With DV, the display is off except for the small area. So the black demo doesn’t really w…

Just a few words in short:
I recently requested a feature that allows Plex to play dual-layer Dolby Vision (also known as profile 7 DV). Some of the guys mentioned above assumed that even if Plex is willing to support dual-layer DV it would probably not work since the respective device must(!) also support dual-layer DV.
In case of the Nvidia Shield 2019 @crazydave80 stated that he got the information from Nvidia that the Shield does not support dual-layer DV.

The main reason why I requested dual-layer DV was because only one single tool is able to make single-layer DV from UHDs (DVDFab). Unfortunatelly, there some serious hints (wrong color space and static metadata) that the single-layer DV from DVDFab is somekind of ‘bogus’ single-layer and thus it seems to be senseless that Plex supports single-layer at all.
Please read details about this issue in the request thread (see above)!

So from the current status is that single-layer DV (what can only made a single high-priced tool) is fake and therefore it seems to be senseless that Plex supports it. However, there is currently a minimum change that we get dual-layer support (for the Nvidia Shield) because itself does not support it.

However, @KCX and me had a long disccusion and we assumed that the single-layer DV made by DVDFab looks not very different compared to dual-layer DV mp4s or the original UHD material.
So even if this single-layer DV is fake, it seems to look not very different…
If this is correct, then the guys from DVDFab found a way to get their single-layer DV look like “real” DV or the guys who suggested that is fake are wrong.

@KCX did some testing, yesterday: Dolby Vision not working on 7.24 with single layer mp4 files - #159 by KCX
He used Dolby Vision material from some demo videos.
These results look very interesting as I (personally) see no difference between dual-layer DV and single-layer DV (made by DVDFab).

thats impressive and made me also do some testing.

Here are some results:
Basically, it is important to use a standardized setup with the same lighting conditions etc. For the present investigation I used the following setup:
Camera: Nikon D800
Lens: Nikon AF-S Nikkor 14-22mm 1:2.8G ED
Focal distance: 24mm (static)
Iso: 800 (static)
aperture: f/2.8 (static)
shutter: 1/4 (static)

TV: Panasonic GZ200 (in Germany it is called “GZW2004”)
Player: Nvidia Shield TV Pro 2019
Dark room with no extra light.

As you may see, I did not cange (‘static’) some of the values to ensure that perceptual differences in e.g., lighting do not arise from different camera modes.
I tried different shutter levels and came up with 1/4 sec because it (the resulting picture on my computer screen) look most similar to the picture on the TV screen.

Chosen scene was from the movie Hereditary. There are some very contrasting scenes with respect to lighting and color.

Materials:

• Single-layer: DVDFab
• Dual-layer: DVDFab
• UHD DV (direct played from a UHD player): UHD
• Regular HDR10
• FullHD: Blu-Ray (no DV)

I did not use Plax, as it cannot play dual-layer or UHDs. I used the native player from my TV (or the UHD player).

Full HD (1080p) - no HDR/DV

HDR10:

UHD DV

Dual-Layer DV:

Single-Layer DV (from DVDFab):

I will upload more results later this day.

As you might see, there a certain differences between FullHD (that was clear), HDR and DV.
I (personally) see no strong differences between dual-layer DV, UHD DV and single-layer DV from DVDFab.
Relating to single-layer DV from DVDFab, there are, however, some marginal differences in the coloration…

I will post some other caputes later that have some very small differences relating to dual-layer and single-layer.

One more thing:
The fact that the SL DV from DVDFab is slightly different with respect to the coloration may result from a) the TV’s DV mode in general or b) the discussed point that this SL DV is a wrong color space

EDIT:
The pictures are now censored and I hope that it is now ok and is not violating any forum rules. To all mods, please tell me if you see any problems.

[bjs59]

I would suggest you find a different screen capture, picture, or whatever you call them then what you are posting… A naked man standing in a doorway is probably not the best choice on your part and will likely get reported and removed… I’m sure you can find something better to show the point you are trying to make…

[TobyX]

Thank you. I will change that

[bjs59]

No problem… Thank you!!!

[TobyX]

Here is another example from the movie Joker. Only UHD vs. single-layer DV

In this case, you may see a difference in coloration. I found this example very significant.

DV (UHD):

Single-layer DV:

EDIT:
I just changed the picture sizes because of there relative big sizes

[KCX]

Toby thank you for the work and your effort! Good comparison and as you can see there are differences. we will also be able to discuss a lot. ps. I have no problem seeing a half naked man

[bjs59]

@KCX

ps. I have no problem seeing a half naked man

Just to clarify, I don’t have a problem with it either, but there is a time and place for everything… It was just a suggestion before the OP was reported by someone who might be offended… They didn’t have to change anything and take their chances… It was their own choice…

[TeknoJunky]

I know it’s probably crushing to consider, but the dv support in the shield was most likely intentionally/specifically for the big steaming services (Netflix etc), and neither plex nor dual layer dv was even considered.

Just my opinion/observation based on what we have learned so far.

IF dvdfab sldv is real (I have no opinion one way or the other), it does seem apparent from both hearsay and from pictures above, that;

no matter what: dvdfab sldv is DIFFERENT than the original dldv.

This fact may be both obvious and abhorrent in hindsight,.

Because just like most video codec conversions, it is a LOSSY process.

In summary, I believe at this point, playback of lossless/original dual layer dv is going to be a pipe dream for most people. (Outside the obvious sticking disk in player)

Sldv is going to be a compromise.

Standard hdr10 is going to remain the standard (lowest common denominator) for the majority of users, simply by sheer ease of use and compatibility.

No doubt dv will continue to be pursued, but until such time as an open source dv de/en-coder that can work on generic (non Dolby designated) hardware, I suspect dv will remain niche.

[KCX]

When I look at the examples and my tests I think I understand the difference. The monkey tool subsequently turns a dual layer into a single layer. This is not intended and is normally not possible. However, they have found a way to integrate a large part of the DV data into the video.

I think the missing color depth or primaries will be the problem. The Dolby Vision composer and display manager obviously makes a better color picture from the 12-bit source of the EL even if the screen always gets 10 bit YUV 420.

However, the metadata is preserved in whole or in large part, since the brightness and darkness of the SL seem identical to me. I think it’s kind of a HDR10 and DV mix. DVDFab will extract the RPU substream metadata and discard the expanded color. Then he adds the metadata to the first 10bit HEVC layer and replaces or overwrites the static data. The differences to HDR10 could not be explained otherwise!?

Ultimately, it is exactly what the monkey describes.
BL + RPU = “Singel Layer” but without the additional data from the FEL.
I think there will be no other way to do something like that afterwards. So we will never be able to create a real single layer from a UHD disc.

BUT one thing you can’t blame the monkey for is a complete fake. It is not an HDR10 that triggers DV on the TV. It is the 10bit baselayer which is expanded with useful dv data substream and thus comes very close to the original.

Sources and details info:

dolby-vision-uhd-bluray-authoring-workflow.pdf

dolby-vision-bitstreams-in-mpeg-2-transport-stream-multiplex-v1.2.pdf

dolby-vision-white-paper.pdf

[TeknoJunky]

might be of interest

https://blog.beamr.com/2016/06/08/dolby-vision-and-hevc-an-introduction/

they appear to have one of (if not the only) dolby vision encoder outside of the dolby producer package.

kodi thread RE DV profile 5 playback

https://forum.kodi.tv/showthread.php?tid=308090&page=2

[ninja1x1]

Perhaps @TobyX and @KCX are interested in what is happening on the makemkv forum.
https://www.makemkv.com/forum/viewtopic.php?p=85573#p85573
A user appears to have managed to combine the base layer, the enhancement layer and the rpu data into a single track. He took your post (Joker) as example. Several users are testing some files on the new Shield. It would be interesting to know your opinion on the matter (maybe with some photos). Good evening.

[TobyX]

Thank you for the update! I was a bit surprised that this topic seemed to be not of interest. However, I’m glad that some of these guys didn’t give up.

I will look into it and comment on it on the upcoming weekend

EDIT, :
Btw I don’t find his tool on the forum. Do you have a direct link?

[ninja1x1]

you can find it here:
https://www.makemkv.com/forum/viewtopic.php?p=85413#p85413

[TeknoJunky]

thanks for the updated info

from above link thread

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Post by DaMacFunkin » Thu Mar 05, 2020 12:51 pm

I’ve said it before and I’ll say it again, Shield can’t process 2 streams into one output, whether that be Dolby Vision or MVC.

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regardless of whether they will solve effective conversion of dual layer DV into single layer DV, I believe the above quoted statement is true as well.

Further I suspect it is extremely unlikely we will ever get any other hardware devices that will read native DL-DV (ie unmodified 4k/uhd/dolbyvision remuxes) going forward.

Finally, everyone should keep in mind that any dual layer to single layer conversion is not lossless. (simply due to the different profile limitations and loss/conversion of enhancement layer data)

[TobyX]

@TeknoJunky

Further I suspect it is extremely unlikely we will ever get any other hardware devices that will read native DL-DV (ie unmodified 4k/uhd/dolbyvision remuxes) going forward.

Afaik this Chinese Oppo player clone can actually play DL-DV natively… however I also expect that there will be no licensed product

[TeknoJunky]

yeah I am referring to any new devices for the future.

from what I gathered from the thread, the oppo, sony and lg are the only dual layer player devices (but not through plex).

[TobyX]

I am currently content with single-layer DV made by DVDFab since I do not see major differences. Only in some cases (ie example scene from Joker) there are some significant differences notable… however, I would love to see that DVDFab will do a better/more reliable job.

But as you stated: the process of converting is indeed not lossless so we will never get 1:1 …

[TeknoJunky]

can you advise if your SLDV videos will play correctly on non-dolbyvision tv?

because if not, SLDV will not be of much use to any devices without DV.

and I sincerely doubt that plex will ever do SLDV to SDR conversion, even IF they ever do HDR to SDR conversion.

[TobyX]

That’s a good question. Looking at ‘mediainfo’ it states that these SLDV videos are HDR10 compatible (I do not have any clue what does it mean in detail).

Unfortunately, I do not have a non-DV but HDR compatible device at home… I only have a DV + HDR UHD TV. My brother also accesses my PMS and he has a Samsung TV that “only” supports HDR10+/HDR10. I’ll ask him to play one of my SLDV movies vs HDR10 vs original UHD.
Beside the fact that he told me that he doesn’t care about HDR, maybe he sees any differences

[ninja1x1]

@TeknoJunky

Finally, everyone should keep in mind that any dual layer to single layer conversion is not lossless. (simply due to the different profile limitations and loss/conversion of enhancement layer data)

The procedure he uses appears to be a 1:1 transposition of a bluray disc.
https://www.makemkv.com/forum/viewtopic.php?f=12&t=18602&start=1260#p85181
https://www.makemkv.com/forum/viewtopic.php?f=12&t=18602&start=1260#p85231

You should read the whole thread. It is very informative.

The Shield’s capabilities are being discussed in recent posts (for this reason I was asking for the opinion of @TobyX)