MP4 with Dolby Vision in a separate track -> MKV with a single video track

[bond_007]

Hi.
I have an MP4 UHD Bluray Remux file that seems to have two video tracks, with the 2nd track being a 1080p solid green video with Dolby Vision:

General
 Complete name                            : ***.BDREMUX.2160p.HDR.DV.***.mp4
 Format                                   : MPEG-4
 Format profile                           : Base Media / Version 2
 Codec ID                                 : mp42 (mp42/dby1/isom)
 File size                                : 46.8 GiB
 Duration                                 : 1 h 46 min
 Overall bit rate                         : 63.1 Mb/s
 Encoded date                             : UTC 2019-10-21 14:04:23
 
 Video #1
 ID                                       : 1
 Format                                   : HEVC
 Format/Info                              : High Efficiency Video Coding
 Format profile                           : Main 10@L5.1@High
 HDR format                               : SMPTE ST 2086, HDR10 compatible
 Codec ID                                 : hev1
 Codec ID/Info                            : High Efficiency Video Coding
 Duration                                 : 1 h 46 min
 Bit rate                                 : 62.6 Mb/s
 Width                                    : 3 840 pixels
 Height                                   : 2 160 pixels
 Display aspect ratio                     : 16:9
 Frame rate mode                          : Constant
 Frame rate                               : 23.976 (24000/1001) FPS
 Color space                              : YUV
 Chroma subsampling                       : 4:2:0 (Type 2)
 Bit depth                                : 10 bits
 Bits/(Pixel*Frame)                       : 0.315
 Stream size                              : 46.4 GiB (99%)
 Default                                  : No
 Encoded date                             : UTC 2019-10-21 14:04:23
 Color range                              : Limited
 Color primaries                          : BT.2020
 Transfer characteristics                 : PQ
 Matrix coefficients                      : BT.2020 non-constant
 Mastering display color primaries        : Display P3
 Mastering display luminance              : min: 0.0001 cd/m2, max: 1000 cd/m2
 Codec configuration box                  : hvcC
 
 Video #2
 ID                                       : 2
 Format                                   : HEVC
 Format/Info                              : High Efficiency Video Coding
 Format profile                           : Main 10@L5.1@High
 HDR format                               : Dolby Vision, Version 1.0, dvhe.07.06, EL+RPU, Blu-ray compatible / SMPTE ST 2086, HDR10 compatible
 Codec ID                                 : dvhe
 Codec ID/Info                            : High Efficiency Video Coding with Dolby Vision
 Duration                                 : 1 h 46 min
 Bit rate                                 : 65.3 kb/s
 Width                                    : 1 920 pixels
 Height                                   : 1 080 pixels
 Display aspect ratio                     : 16:9
 Frame rate mode                          : Constant
 Frame rate                               : 23.976 (24000/1001) FPS
 Color space                              : YUV
 Chroma subsampling                       : 4:2:0 (Type 2)
 Bit depth                                : 10 bits
 Bits/(Pixel*Frame)                       : 0.001
 Stream size                              : 49.6 MiB (0%)
 Default                                  : No
 Encoded date                             : UTC 2019-10-21 14:04:23
 Color range                              : Limited
 Color primaries                          : BT.2020
 Transfer characteristics                 : PQ
 Matrix coefficients                      : BT.2020 non-constant
 Mastering display color primaries        : Display P3
 Mastering display luminance              : min: 0.0001 cd/m2, max: 1000 cd/m2
 Codec configuration box                  : hvcC+dvcC

Is this a valid UHD Bluray remux with all original video and Dolby Vision data intact?
By the way, notice the HDR format of the second video track says "EL+RPU" and not " BL+EL+RPU" - I don't know what it means.
This file is played for me as HDR and not DV.
Is it possible to convert it to an mkv file with a single video track that includes the DV data, and without any data loss, so it will be similar to other files I have that are played well as DV?
If so, how?

What I want is something like this (example of a file I have that is played as DV):

General
 Unique ID                                : ***
 Complete name                            : ***.2160p.BluRay.REMUX.HEVC.DTS-HD.MA.TrueHD.7.1.Atmos***.mkv
 Format                                   : Matroska
 Format version                           : Version 4
 File size                                : 77.9 GiB
 Duration                                 : 2 h 43 min
 Overall bit rate mode                    : Variable
 Overall bit rate                         : 68.2 Mb/s
 Movie name                               : ***
 Encoded date                             : UTC 2021-12-14 05:56:16
 Writing application                      : mkvmerge v63.0.0 ('Everything') 64-bit
 Writing library                          : libebml v1.4.2 + libmatroska v1.6.4
 
 Video
 ID                                       : 1
 ID in the original source medium         : 4113 (0x1011)
 Format                                   : HEVC
 Format/Info                              : High Efficiency Video Coding
 Format profile                           : Main 10@L5.1@High
 HDR format                               : Dolby Vision, Version 1.0, dvhe.07.06, BL+EL+RPU, Blu-ray compatible / SMPTE ST 2086, HDR10 compatible
 Codec ID                                 : V_MPEGH/ISO/HEVC
 Duration                                 : 2 h 43 min
 Bit rate                                 : 56.6 Mb/s
 Width                                    : 3 840 pixels
 Height                                   : 2 160 pixels
 Display aspect ratio                     : 16:9
 Frame rate mode                          : Constant
 Frame rate                               : 23.976 (24000/1001) FPS
 Color space                              : YUV
 Chroma subsampling                       : 4:2:0 (Type 2)
 Bit depth                                : 10 bits
 Bits/(Pixel*Frame)                       : 0.285
 Stream size                              : 64.7 GiB (83%)
 Language                                 : English
 Default                                  : No
 Forced                                   : No
 Color range                              : Limited
 Color primaries                          : BT.2020
 Transfer characteristics                 : PQ
 Matrix coefficients                      : BT.2020 non-constant
 Mastering display color primaries        : Display P3
 Mastering display luminance              : min: 0.0001 cd/m2, max: 1000 cd/m2
 Maximum Content Light Level              : 1000 cd/m2
 Maximum Frame-Average Light Level        : 901 cd/m2
 Original source medium                   : Blu-ray

Thanks!

[Ennio]

Both remuxes seem ok and have all DoVi data that was originally on disc. You can tell by Profile 7 being mentioned. There is a difference in build-up between the mp4 and mkv though. Note the difference in number of videostreams.

For Dolby Vision on UHDBD, Profile 7 DoVi is used. It consists of two separate .hevc streams that each hold a layer: BL (baselayer) and EL (enhancement layer). The mp4 contains the exact two .hevc streams as they are on disc. For P7 DoVi mkv, the two layers have to be interleaved into one .hevc track. This is - next to decrypting - exactly what software like MakeMKV does. With Profile 7 the RPU (which is Dolby Vision's dynamic metadata) is always carried in the EL.

It's up to a player what container types but also what DoVi profiles are supported. Where a lot of DoVi mediaplayers are able to handle RPU, but often have no support for FEL. Which stands for Full Enhancement Layer: next to RPU, FEL carries additional, differential 10-to-12-bit videodata.
To be complete, in case EL does not have this - thus only carrying RPU - it's called MEL. Which stands for Minimum Enhancement Layer.

[bond_007]

Thanks for the explanation!
Do you know how to convert the first file (with the two video tracks) into the format of the second file (with the one video track), without any data loss?

[Ennio]

First thought and easiest way would be to see if MakeMKV would accept the DoVi mp4 as input. I never tried tbh.

I do a lot of Dolby Vision stuff manually. In this case, I'd first demux the mp4 into elementary streams. The resulting "BL.hevc" and "EL.hevc" I interleave into one hevc-stream with the "mux" command of quietvoids's dovitool:

https://github.com/quietvoid/dovi_tool

This result can be imported into MKVToolNix for creating DoVi P7 mkv. When muxing Dolby Vision, always force-set the "Default duration/FPS" to the proper value.


At the doom9 forums, -QfG- has put much effort in writing scripts that can take over a lot of manual labour.

https://forum.doom9.org/showthread.php?t=183479



Also, you may want to check out the main DoVi thread at the MakeMKV forums:

https://forum.makemkv.com/forum/viewtopic.php?p=141627#p141627

Where member RESET_9999 put a lot of work in his "DoVi_Scripts and Tools". You'll find the link in his signature.


Reading the stream-size of EL in your mp4 data, I think the EL is MEL. So only carrying RPU. In which case you could also opt for creating a Profile 8 DoVi file. P8 is widely used and much supported. With Profile 8 there is no EL; RPU will be carried by the BL (BL+RPU). P8 is considered "equivalent" to P7 with MEL as it holds all video- and DoVi data that was on disc. Native P7 RPU does have to be converted to P8 RPU prior to "injecting" (as it's called) in BL. Which all can be done with quietvoid's dovitool, but the scripts can help you do it maybe easier.