Dolby Vision Atmos update

One of the basic requirements of FEL decoding is a second HEVC decoder which neither the Shield nor the Zidoo has.

So if the Shield is playing FEL encodes, then at the very best it's just using the 10-bit HDR10 base layer with the RPU - it certainly isn't passing the 4K Base layer and 2K enhancement layer to the TV in the same way a UHD BluRay player does and neither is it performing Player Led decoding in the way that, for example, the Oppo can.

In both the Shield (FEL & MEL) and the Zidoo (MEL), if you play back profile 7 DV content the actual video you see is the 10-bit HDR10 base layer only and I assume (but don't know for sure) that the tone mapping is done by the RPU.

 

The problem I have with FEL to MEL is this:

UHD BluRay players use the 10-bit (full) enhancement layer along with the 10-bit HDR10 base layer to reconstruct a compressed version of the original 12-bit Dolby stream - the idea is that you're then getting a fair representation of the original 12-bit Dolby Master (or Mezzanine) on your TV at home.

By stitching dvhe.07.06 BL+FEL+RPU together into dvhe.08.06 BL+RPU, on the one hand, if it's a profile 8 stream to specification, then the base layer is HDR10 by definition (dvhe.08 can have either an HDR10, SDR or HLG base layer) and on the other hand it's a 10-bit stream.

Now I can understand if this process does not stick to specification and you lose the HDR10 compatibility, but you certainly can't fit 12-bit 4:2:0 into 10-bit 4:2:0 so data is lost somewhere down the line.

Basically, by converting FEL to MEL you're getting the satisfaction of having your TV tell you it's playing Dolby Vision without the benefit (small that it is) of the original 12-bit Dolby stream.

 

I think the loss with the MEL so the dvhe.08.06 BL + RPU is the EL layer which at the end of the day is kind of a 10% test pattern (gray).
Besides, the EL layer is readable on its own, which gives a gray screen with fluctuations.
This may explain the 'black floor is raised', so too dark colorimetry

 

Are you saying that it's better to use the FEL to MEL tools of this guide (https://www.makemkv.com/forum/viewtopic.php?f=12&t=18602&p=96282#p96282) rather than the FEL to 8.1 profile ? Does this preserve more information ?

 

Hi, I'm a real noob and I've only made MEL encodes. This method you mencioned will work of .mkv FEL encode made by MakeMKV with the tool he made?

 

Yes

 

I'll try that! Thanks

 

A Minimal Enhancement Layer is simply a mid grey flat field and is basically there for compatibility - it adds nothing to the image which is an HDR10 video with dynamic metadata.

A Full Enhancement Layer is an actual 2K Dolby video stream and is the encoded "difference signal" between the 12-bit Dolby stream and the 10-bit HDR10 stream, so on its own it looks a bit like a strange negative video image. When combined in a Dolby decoder, the original 12-bit video is reconstructed which is something that doesn't happen with a Minimal Enhancement Layer and can't be represented in 10-bits (assuming the same subsampling).

It wouldn't explain any deviance in black levels.

 

As far as I can see both do the same job.

 

And do you think a FEL to MEL conversion of a movie is worth than an original MEL movie ?

 

and to add to that, is a fel conversion worth the time and effort, vs say vs10 (compatibility off) so lldv ?? or just leave it on auto and enjoy regular hdr ??

mel is too easy not to do the conversion.

 

fel to mels are taking an hour or so now i have it down ,with images i already had waiting to do them
once the smb pausing isues are sorted since .90 , and the occassional Fel movie that has a stop round half way in ,which i think mark said is a known issue being worked on ,on another thread , id say well worth it even just for the file reduction vs complete image

 

Personally, if you have a MEL BluRay then rip with MakeMKV and you get the Dolby Vision data as it's laid down on the disc. You can choose whether to watch in HDR10(+) or DV. It's most probably best to watch in DV if the RPU is used by VS10 (which we only assume at the moment).

As for a FEL movie - again, I'd rip with MakeMKV to keep all the data - my understanding is this saves both layers as is but in a single track. I'd like to know more about the process of converting to Profile 8 before I made any judgement on that but it does no harm as long as you have the original MakeMKV rip, although my feeling is it's probably not worth the effort in terms of image uplift, but hey, this is all about experimentation!

 

Yes - I've sent a couple of debugs at freeze points - my go to disc for that is 2001 A Space Odyssey which is dvhe.07.06 BL+MEL+RPU DTS-HD and freezes at approx. 1 hour 16 minutes every time.

 

@Markswift2003 You may have answered this before, but I've never found a clear answer on the web when I've searched, so I was curious if you knew. Is it correct for the Rec. 2020 flag to be set on TV-led RGB-based Dolby Vision? I've noticed that the Oppo UDP-203, Apple TV 4K, Fire TV Cube Gen 2, and 2019 Shield TV (after a recent update), do not set the Rec. 2020 flag as true with TV-led RGB-based Dolby Vision on my LG C9. However, the Zidoo Players (with DV compatibility switch enabled), Panasonic DP-UB9000, 2020 Roku Ultra, and Chromecast w/ Google TV do still set the Rec. 2020 flag to true with TV-led RGB Dolby Vision.

 

Technically yes, but since each TV has different primaries defined in the Dolby Block in reality it doesn't really matter - but those primaries are always defined limits within Rec.2020.

The only TV (outside of professional displays) I'm aware of that comes close to Rec.2020 primaries is the LG C9 but in all cases a target needs to be set, hence the primaries are always defined within the Rec.2020 "container" whether they reach it or not.

Other than Profile 4 (Rec.709), Profile 5 (IPT) , Profile 8.2 (Rec.709), Dolby Vision uses the Rec.2020 container.

 

So in essence, you're saying it doesn't really matter what the source device passes for that value in TV-led Dolby Vision? I'm curious why Nvidia updated the Shield to remove the Rec. 2020 flag on TVs that supported TV-Led Dolby Vision then. Should they not have updated it to behave in that way? I know some people claimed removing that flag from the Shield signal via an HDFury, when it was still passing it, improved some of the DV color issues with the device. I never personally tested it myself though.

 

Can't see how it would affect the colours - for Dolby Vision, that's the job of the colour primaries defined in the Dolby Block in the EDID. My guess would be wishful thinking or a misunderstanding of what they're sending... I wouldn't worry about it.

 

I followed that thread and people claimed that removing the flag via a fury removed the red push, Nvidia implemented the change and it didnt, I think some people had their shield set to rec709 default output and removing the flag somehow left them with rec709 on some profiles.

 

Hello Mark

For information :

Either with the FW 0.85 or the FW 0.90, I have to continue to use these options to have a smooth playback with the MKV DV

See you