Dolby Vision now possible through MP4 Mux.

[RESET_9999]

So when I take DV m2ts file from a UHD BD and convert it to a MKV with MKVtoolnix, then merge the dual layer DV tonsingle layer with makeMKV, what do I get as a result?

you get a lossless single-track dual-layer profile 7 files.

look at the end of this excel sheet, all the profiles are explained:
https://docs.google.com/spreadsheets/d/ ... sp=sharing

[drew_nickel]

@reset_9999
or to anyone else who would be kind enough to answer a few questions that I have in regards to dual layer FEL

1.) Is the reason the FEL layer file size is so much bigger than the MEL version because the FEL contains 12bits of color data, which has exponentially more color data than the 10bit MEL version?

2.) If the mediainfo for a certain movie says this about the FEL layer:
MPEG-H HEVC Video 7564 kbps (10.95%) 1080p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 4:2:0 / 10 bits / 1000nits / Dolby Vision FEL / BT.2020
Doesnt it mean the FEL is basically pointless since it was Mastered in 1000nits and 10bit?

3.) I have a CX (700-800 nits max). Since my display wont even go over 1000 nits (no where even close to 4,000 or 10,000) would I benefit at all from having a DV player capable of playing Dual layer FEL? or would the player basically output the same thing as the single layer MEL version?

thanks!

[RESET_9999]

1- FEL data is the difference between the 12bits master and the 10bits encode.
It can contain extra details/grain especially noticeable with movies poorly encoded like Total Recall See: https://slow.pics/c/dgibQoJ1

2- Regardless of how bright the movie was graded, DV appears to look always different than HDR10 on my LG C8. Better tone mapping I guess.

3- Unless they messed up the HDR10 encode, the difference between FEL and MEL is very small and probably unnoticeable most of the time on our 10bits TVs. But it does feel good to know you're getting the best quality possible .

[nekno]

Just to expand on this a little.

1.) Is the reason the FEL layer file size is so much bigger than the MEL version because the FEL contains 12bits of color data, which has exponentially more color data than the 10bit MEL version?

When dealing with DV Profile 7, you have a Base Layer and an Enhancement Layer.

A 12-bit 4K master is graded and then analyzed by DV software and processed into a 10-bit 4K HDR10 base layer, a 10-bit 1080p enhancement layer, and the Reference Processing Units (RPUs) containing dynamic metadata — characteristics of the brightness from scene to scene and the tone mapping trims for different display capabilities.

The EL contains the residual video signal that's the difference between the 12-bit master and the HDR10 BL.

An FEL contains the full 1080p video stream with the residual video data plus the RPUs.

An MEL has the video data stripped out; it has a null video stream or mid-gray static field, and is just used to carry the RPUs. Or, as I understand it, if there was only a 10-bit master produced there may have never been the extra 2 bits of color data available, so there was no video data the FEL needed to carry.

2.) If the mediainfo for a certain movie says this about the FEL layer:
MPEG-H HEVC Video 7564 kbps (10.95%) 1080p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 4:2:0 / 10 bits / 1000nits / Dolby Vision FEL / BT.2020
Doesnt it mean the FEL is basically pointless since it was Mastered in 1000nits and 10bit?

The FEL just contains the 2-bits of diff between a 12-bit master and 10-bit BL. It's recombined with the BL in a proprietary DV process to recreate a 12-bit 2160p signal from a 10-bit 4K BL + a 10-bit 1080p EL, so you don't need to worry about the video specs too much. The EL video stream isn't be displayed directly, so the specs aren't really relevant. It's using 10-bits of color @ 1080p resolution to represent 2-bits of color @ 2160p resolution. They used a proprietary hack to stuff the 2-bits of data they needed into an existing video format, 10-bit 1080p HEVC video.

3.) I have a CX (700-800 nits max). Since my display wont even go over 1000 nits (no where even close to 4,000 or 10,000) would I benefit at all from having a DV player capable of playing Dual layer FEL? or would the player basically output the same thing as the single layer MEL version?

The RPU contains trim data — adjustments for different brightness displays — often for 100nits (SDR) and 600nits. When your device's EDID indicates an 800nit max, the 100nit and 600nit trims are used to produce a picture that's as close as possible to the 10000nit or 4000nit or 1000nit master.

That will be true with either an MEL or FEL.

And it's true that the 2bits of color data in an FEL usually mostly represent brightness beyond your display's capabilities.

So in a lot of cases the FEL will contain data brighter than your display can presently handle and it isn't that useful, but in other cases (as shown in the Total Recall snapshots) the FEL video data actually adds more clarity and detail because of the way the data was split apart in the encoding process.

So MEL and FEL encodings are both capable of exceeding the capabilities of most displays, but if you want to be sure you're getting the best possible video quality, you go with the FEL. Without analyzing the contents of a specific FEL video stream, or seeing it rendered with the BL+EL combined, you won't really know what you're missing.

[Mattl0]

Anyone tried the 5.0 fw from Ugoos on am6 b? Wonder how’s the dv playback. I will test it when I have time (currently the unit is somewhere, need to find it lol) .

F9220A1F-B95D-4B07-83FB-19CFD5159257.pngC8E9B873-8502-4BDF-B4FD-3602ACEBADDC.pngA594274E-B3FB-4A57-91F1-051FBD0A3621.jpeg

Do you know where I can download the firmware from?

Sorry , no, that was only a news from Ugoos . It it not out yet

[RESET_9999]

great explanation @nekno
I'll pin your comment in the excel sheet. thanks

[deadchip12]

Hi. Question: say I have a good wifi 6 router that has a usb port. Can the sony x700 access the movie files I store in an external hdd somehow and play them well if I connect that hdd to the router via the usb port and connect the router to the sony x700 via the lan port?

[FubbAyH]

It could theoretically work if the router has the feature of running as a DLNA server to serve the files on the device plugged into its USB port. But, according to @RESET_9999's excellent playback devices info spreadsheet, there's a problem that the x700 only has slow 100Mbps ethernet and slow wi-fi, so it will struggle with high bitrate movies (which are common with UHD Blu-ray rips), so it's better to plug the USB device straight into the x700.

[deadchip12]

It could theoretically work if the router has the feature of running as a DLNA server to serve the files on the device plugged into its USB port. But, according to @RESET_9999's excellent playback devices info spreadsheet, there's a problem that the x700 only has slow 100Mbps ethernet and slow wi-fi, so it will struggle with high bitrate movies (which are common with UHD Blu-ray rips), so it's better to plug the USB device straight into the x700.

Yeah I noticed the 100Mbps port spec just now... Such a shame. I really wanted to find a way for playing the movie files on the x700 without having to physically move the hdd back and forth between the bluray player and my pc.

[drew_nickel]

great explanation @nekno
I'll pin your comment in the excel sheet. thanks

Yes! great explanation @nekno! Thank you guys for helping me understand it. Thank you too @reset for all your help! Your scripts are excellent! I use your method and I also use @yusesope's and I've been making alot excellent and flawless conversions

The size of the FEL layer is what baffled me the most. Didnt realize that it was its own video stream of the 1080p. Makes alot of sense now. I've been looking for that answer for a while now

And that Total Recall screenshot comparison is really helpful and interesting too

[ArArdin]

Just to expand on this a little...

Kudos indeed for your clear explanation, nekno.

Could you explain why the enhancement layer is always shown as 1080p and not in 4K resolution?
I can imagine it's just extra sub-sampling into a smaller footprint for compression efficacy. Where I wonder if this would be possible because the data itself is differential, and/or the source being encoded in 4:2:0 color subsampling.

Any thoughts?

[aboulfad]

…
The RPU contains trim data — adjustments for different brightness displays — often for 100nits (SDR) and 600nits. When your device's EDID indicates an 800nit max, the 100nit and 600nit trims are used to produce a picture that's as close as possible to the 10000nit or 4000nit or 1000nit master.

That will be true with either an MEL or FEL.
…

Thank you for an interesting read, complimentary to the very useful post viewtopic.php?p=85181#p85181 about DoVi tracks/layers by yusesope.
IYO, what is the impact on screen by screen (or frame) display brightness when a workflow is followed to convert DV P7 DTDL BL+MEL+RPU to P5 STSL BL+RPU where the EL (MEL) is discarded? (Putting aside the color space differences)

[nekno]

Could you explain why the enhancement layer is always shown as 1080p and not in 4K resolution?
I can imagine it's just extra sub-sampling into a smaller footprint for compression efficacy. Where I wonder if this would be possible because the data itself is differential, and/or the source being encoded in 4:2:0 color subsampling.

Any thoughts?

The short answer: Because that's what the DV spec specifies for P7. It was just a choice to make it work within the UHD BD spec, for efficiency and bandwidth. You only need to encode 2 bits of color data in the EL; you don't need a full 2160p 10-bit stream for that. Moreover, decoding two simultaneous 2160p60 HEVC streams @ 130Mbps requires twice the throughput of the overall system as compared to a single stream. Lowering the max EL down to 1080p60 @ 70Mbps lessens those hardware/software constraints considerably (from 2x to ~1.5x for the coded picture, and from 2x to 1.25x for the decoded picture).

The long answer, breaking down Dolby Vision Profiles and Levels:

As we know, DV has profiles, which specify:

• video codec, video profile, and video level
• single or dual layer (BL+RPU or BL+EL+RPU)
• cross-compatibility IDs (CCIDs) that specify the BL characteristics (SDR, HDR10, HLG)

DV Profile 7 specifies:

• 10-bit HEVC video (HDR10) for both BL and EL
• a 1:1 ratio in BL:EL if the BL is FHD (1080p), which equates to a max of DV Level of 5
• a 1:1/4 ratio in BL:EL if the BL is UHD (2160p), with a max DV Level of 9

So DV also has levels.

The Profile specifies constraints on the Level based on the specs of the BL.

So if you want a BL of 3840*2160*24fps = 199,065,600 pixels per second (pps), that equates to DV Level 6:



So with DV Level 6, you're beyond the limit of DV Level 5 for a 1:1 BL:EL ratio, and therefore the EL has to drop to 1/4 the pps of the BL, per the spec. The pps of DV Level 5 is 1/4 the pps of DV Level 9, hence a BL of Level 9 will be limited to an EL of Level 5.

With a BL of DV Level 6, which is where you see UHD BD P7 encodes, 1/4 the pps limits you to an EL of Level 3. And basically you only see UHD BD movies with BLs of at least Level 6, because that's what you need for 2160p24, and only ELs of Level 3, because that's what you need to support 1080p24.

When you see "dvhe.07.06", that's a "DV codec string" that's specifying:

• DV Profile string: "dvhe.07" — Dolby Vision, HEVC video codec, Profile 7
• DV Level ID: "06" — the max pps specified by Level 6

Lastly, you have the CCID (which isn't included in the DV codec string):

• when you see "DV 8.1", "DV P8.1", or "DV Profile 8.1", that's specifying:
  • Profile: 8 — all the constraints of DV8
  • CCID: 1 — which specifies the BL must be HDR10
• when you see DV 8.4, that's specifying:
  • Profile: 8
  • CCID: 4 — which specifies the BL must be HLG

[quietvoid]

If anyone's interested, I just added muxing BL+EL to dovi_tool.
There's no release yet but testing would be nice, more info here: https://github.com/quietvoid/dovi_tool/ ... 1114074639

This now makes dovi_tool feature complete in comparison to yusesope's script. It's also faster.

edit: It is now available in version 1.5.0: https://github.com/quietvoid/dovi_tool/ ... /tag/1.5.0

[RESET_9999]

thanks... seems to work well and faster indeed.