[DDVT Tool] Dolby Vision RPU Demuxing / Injecting / Editing.

[quietvoid]

The EL is required (expected at least) to be in sync with the BL, at the bitstream level (decoding timestamps).
So you can't just re-encode and add it back. It won't be valid for the re-encoded video, even if it was in sync.

If you plan on re-encoding you need to process the EL beforehand so that its effects are present in the video itself.

[lemaireus]

GodzillaAvenger, I continue to stick with the PC as the core around which my home theatre system is organised and have thus far not used Ugoos or any other hardware players. My feeling is that we are still some distance away from that inflection point at which Dolby Vision becomes as universally supported and accessible as once upon a time, for example, x264 after DivX and xVid. There is already so much wonderful work put in by the open-source community--quietvoid, -QfG-, Kuler087, to mention only three on Doom9--that by the end of 2025, I think, we should have fairly widespread support for DV encoding and playback. The hardware too, by the same logic, should improve by leaps and bounds, and at the moment, with my level of expertise--rather, lack of it--all I can do is to wait for software and hardware support for DV to mature past that inflection point at which it becomes useful for someone with my skill level.

At the moment I use Energy Media Player, suggested by Kuler087, on my HTPC for DV playback. I used to think that MPC-HC--the latest builds on GitHub--supports DV (it claims "MPCVR also supports Dolby Vision"), but Kuler told me that it merely tone maps the colour space to HDR10 while ignoring dynamic metadata. Ideally, I would be looking for a player which can simply passthrough DV metadate to the display so that the TV can do the work it was bought to do.

I had no idea that some of the FELs are fake. Thank you for sharing that information, even if that muddies the waters even more for me.

[lemaireus]

Originally Posted by quietvoid

The EL is required (expected at least) to be in sync with the BL, at the bitstream level (decoding timestamps).
So you can't just re-encode and add it back. It won't be valid for the re-encoded video, even if it was in sync.

If you plan on re-encoding you need to process the EL beforehand so that its effects are present in the video itself.

Sigh!

Thank you for sharing that information, quietvoid. That will save me lots and lots of wasted hours of work, not counting the ones already in the dump.

Thus far, I have been re-encoding UHD blu-rays with RibBot264 (10-bit, x265), and then, using DDVT, demuxing and injecting the EL or the RPU from the blu-ray back into that encode, assuming that the BL is preserved in the RipBot encode. I've done nearly 1500 movies using this method; all to no purpose, it appears.

I'll just keep my fingers crossed and hope that you all of you guys working on DV can tame the hydra-headed monster to the point at which the technologically-challenged such as myself can use it without feeling utterly lost.

Is there no point in injecting an RPU either to a re-encode? Thus far I've been working with the idea that timestamps and frame numbers remain unchanged, are carried over without any change, across any number of encodes. And this after twenty-plus years of re-encoding. One learns the hard way, I suppose.

[SeeMoreDigital]

Originally Posted by GodzilaAvenger

Something that you may not know is that some of those FEL are fake. If the EL bandwidth is around 2 Mbps or less, the FEL is just a grey static image and you can discard it and only keep the RPU. Based on my experience out of the major studios that use DV (so not Disney and their cheap a**), WB and Sony generally include the fake FEL and only Universal and Paramount have a real FEL (if you look at their FEL bandwidth it's usually ~5-10 Mbps).

I thought the Dolby Vision encodes with a 'green' (not grey) static image' video track were MELs...

[quietvoid]

Originally Posted by lemaireus

Sigh!
Is there no point in injecting an RPU either to a re-encode? Thus far I've been working with the idea that timestamps and frame numbers remain unchanged, are carried over without any change, across any number of encodes. And this after twenty-plus years of re-encoding. One learns the hard way, I suppose.

The issue only applies to keeping the EL video, because the RPU is synced to that EL video.
And not the re-encoded one.

RPU just needs the metadata associated to the correct frame, which is done by x265 or whatever you use.

I don't know what DDVT does for "injecting the EL or the RPU".
Injecting the RPU is fine. Muxing in the EL is not.

For your existing files, you'd have to check if the EL was kept or not.
It would be a bit more involved to extract/re-inject the RPU if that's the case.

[Skav]

Hi, is it possible to prevent the cmd window from closing by itself, regardless of the script file used ?

[GodzilaAvenger]

Originally Posted by SeeMoreDigital

I thought the Dolby Vision encodes with a 'grey static image' (video) track were MELs...

They are technically FEL because they still have that static image video track. In true MEL the EL is only the RPU and the bitrate is ~100 kbps.

Originally Posted by lemaireus

Is there no point in injecting an RPU either to a re-encode?

As quietvoid mentioned the RPU, when injected alone, only needs frame numbers (you can use DDVT_FILEINFO to convert the RPU binary into a readable .json format and look at the data). A common practice (which I also use) is to extract the RPU from the remux P7.6 and convert it to P8.1 (using something like DDVT_DEMUXER) and then add it back into the re-encoded HDR10 BL using DDVT_INJECTOR. Worth mentioning DDVT uses quietvoid's dovi_tool and hdr10plus_tool to manipulate DV/HDR10+ metadata and FFmpeg/MKVToolNix to work with video files.

Originally Posted by lemaireus

Thus far I've been working with the idea that timestamps and frame numbers remain unchanged, are carried over without any change, across any number of encodes. And this after twenty-plus years of re-encoding. One learns the hard way, I suppose.

Honestly, we're all here to learn. I asked the same questions you did a few years back in this very thread and a lot of folks here helped me out.

[lemaireus]

Originally Posted by quietvoid

I don't know what DDVT does for "injecting the EL or the RPU".
Injecting the RPU is fine. Muxing in the EL is not.

Thank you, quietvoid, for providing that clarity. I'll have to start from scratch, yet again.

Thank you also for all the work that you have put into the HDR tools which DDVT uses to make DV a bit more accessible to the likes of myself.

[lemaireus]

Originally Posted by GodzilaAvenger

A common practice (which I also use) is to extract the RPU from the remux P7.6 and convert it to P8.1 (using something like DDVT_DEMUXER) and then add it back into the re-encoded HDR10 BL using DDVT_INJECTOR. Worth mentioning DDVT uses quietvoid's dovi_tool and hdr10plus_tool to manipulate DV/HDR10+ metadata and FFmpeg/MKVToolNix to work with video files.

I guess I have no choice but to go down that route as well. Retaining only the RPU and converting that from profile 7.6 to 8.1 seems to be the safest option and also the best supported one in playback.

Originally Posted by GodzilaAvenger

Honestly, we're all here to learn. I asked the same questions you did a few years back in this very thread and a lot of folks here helped me out.

The real question here would be: is there an application out there which can help someone with my rudimentary familiarity with Dolby Vision keep the FEL/MEL intact and synced?

Has anyone tried DoVi_Scripts? If yes, does that keep the EL perfectly synced with the BL, while providing flexible bitrate control (to manage output file size, when necessary) and, importantly for me, has the application's GUI become user-friendly enough for tech-challenged users?

[GodzilaAvenger]

I haven't used DoVi_Scripts, but I think DoViBaker may be closer to what you are looking for (haven't used it either, just saying based on the documentation).

[lemaireus]

Originally Posted by GodzilaAvenger

I haven't used DoVi_Scripts, but I think DoViBaker may be closer to what you are looking for (haven't used it either, just saying based on the documentation).

Thank you for the suggestion. I shall check out DoViBaker.

[SeeMoreDigital]

Originally Posted by GodzilaAvenger

They are technically FEL because they still have that static image video track. In true MEL the EL is only the RPU and the bitrate is ~100 kbps.

So are you saying that all Dolby Vision encoded 4K UHD Blu-ray discs are FEL but some are more FEL than others?

So this 'secondary' video stream is considered to be 'full' FEL: -


But this 'secondary' video stream is considered to be 'fake' FEL: -


I was under the impression that Dolby Vision encodes with 'green' secondary streams (like the one above) are 'MEL'...

[GodzilaAvenger]

Your examples for the difference between FEL and fake FEL are spot on. That said, some DV disks are actually MEL. Here's an example:

Casino Royale (MEL):

Video: MPEG-H HEVC Video / 41863 kbps / 2160p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / HDR10 / BT.2020
* Video: MPEG-H HEVC Video / 65 kbps / 1080p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / Dolby Vision / BT.2020

2001: A Space Odyssey (fake FEL):

Video: MPEG-H HEVC Video / 62181 kbps / 2160p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / HDR10 / BT.2020
* Video: MPEG-H HEVC Video / 2093 kbps / 1080p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / Dolby Vision / BT.2020

Gladiator (FEL):

Video: MPEG-H HEVC Video / 43317 kbps / 2160p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / HDR10 / BT.2020
* Video: MPEG-H HEVC Video / 6825 kbps / 1080p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / Dolby Vision / BT.2020

For Casino Royale that "1080p track" is actually just the RPU (based on the bitrate), hence MEL.

See this topic, though the list hasn't been updated in a few years.

[Kuler087]

Has anyone tried DoVi_Scripts? If yes, does that keep the EL perfectly synced with the BL, while providing flexible bitrate control (to manage output file size, when necessary) and, importantly for me, has the application's GUI become user-friendly enough for tech-challenged users?

Of course, it can bake FEL: Workflow 8-2-1
Dovi_scripts can do ANYthing that is DV-related and there's no such thing as ''fake FEL''
and all the modes/workflows are described on the main page:

MODE.E (8) =
VIDEO/AUDIO ENCODERS

can convert audio (DDP 7.1 / Add silent or encoded core to TrueHD)
see tutorial (convert to ddp): https://www.youtube.com/watch?v=m5_Bt2yGPhE
see tutorial (add core): https://www.youtube.com/watch?v=X8CImPBh_DI
can encode bake fel to HDR10/P8 with dovibaker+x265 or NVenc
see tutorial: https://www.youtube.com/watch?v=8BvXqw_cGJE
can encode any HDR10/HLG/FELP7/P5 source to HDR or SDR (x265 or NVenc or prores)
can encode DV to SDR using official Level-2 100nits trim pass (Official Dolby cm_offline.exe)
can encode P7/P8 to profile 5 DV (requires DEE.exe)
can encode JPEG2000 IMF mxf and Prores files to profile 5 DV (requires DEE.exe)

[SeeMoreDigital]

Originally Posted by GodzilaAvenger

Your examples for the difference between FEL and fake FEL are spot on. That said, some DV disks are actually MEL. Here's an example:

Casino Royale (MEL):

Video: MPEG-H HEVC Video / 41863 kbps / 2160p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / HDR10 / BT.2020
* Video: MPEG-H HEVC Video / 65 kbps / 1080p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / Dolby Vision / BT.2020

2001: A Space Odyssey (fake FEL):

Video: MPEG-H HEVC Video / 62181 kbps / 2160p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / HDR10 / BT.2020
* Video: MPEG-H HEVC Video / 2093 kbps / 1080p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / Dolby Vision / BT.2020

Gladiator (FEL):

Video: MPEG-H HEVC Video / 43317 kbps / 2160p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / HDR10 / BT.2020
* Video: MPEG-H HEVC Video / 6825 kbps / 1080p / 23.976 fps / 16:9 / Main 10 @ Level 5.1 @ High / 10 bits / Dolby Vision / BT.2020

For Casino Royale that "1080p track" is actually just the RPU (based on the bitrate), hence MEL.

See this topic, though the list hasn't been updated in a few years.

I see... I've posted a few times within that very Blu-ray.com forum topic/thread, indeed I'm even quoted in the second spoiler of the first post, but I wasnt aware of any Dolby Vision discs with secondary video streams encoded at very low bitrates (ie: below 100kbps)!

I have a few Dolby Vision discs encoded with 'green' secondary video streams or "fake FEL" but I don't think I have any "genuine MEL" discs, so I'll have to buy one.



Cheers

EDIT: I've just extracted the secondary video stream from Fifth Element (2h 6m 22s). It's file size is just 143MB and it's bitrate is just 146kbps. When the stream is played in either MPC-BE or VLC the video is green, not grey. Is this 'fake FEL' or 'genuine MEL'?

[kolak]

I would say that green means empty?

[SeeMoreDigital]

Originally Posted by kolak

I would say that green means empty?

I'm interested to know if 'secondary streams' encoded below 100kbps are green or grey?!

[GodzilaAvenger]

Didn't notice you were the one quoted in that post

I'd say Fifth Element is MEL. I don't know why I said the secondary 1080p track is grey, my bad. I guess both MEL and fake FEL show the green image.

Here's how I see this FEL/MEL debate. There are disks like Gladiator where the EL contains both additional picture information and the RPU (EL bitrate higher than 3 Mbps), i.e. FEL. There are also those like Casino Royale and Fifth Element where the EL merely contains the RPU (EL bitrate around 100 kbps), i.e. MEL. Then there are the inbetweeners from (mostly) Sony and Warner Bros. (EL bitrate around 2 Mbps). You could argue these are MEL because, unlike FEL, the EL does not contain any additional picture information. Or, you could argue that these are FEL because, unlike MEL, based on the bitrate the EL contains something in addition to the RPU (what it is is a mystery to me, if someone here knows or has worked at Sony/Warner Bros. please share because I genuinely want to know). I just call them 'fake FEL' to encompass both sides of the argument (this post from -QfG- is also helpful).

At the end of the day, I think this is mostly semantics. The point I was trying to make when answering lemaireus' question was that if they see an inbetweener they can simply keep the RPU and discard the rest of the EL.

[Kuler087]

Forget about the bitrate or the image color. The only reliable and accurate way to tell if a video is FEL or MEL is by reading the RPU header flag.

"dovi_profile": 7,
"el_type": "FEL",


Also, I've seen some 16mb/s EL add visually nothing to the 12-bit decoded stream, and I've seen some 2-3mb/s EL add grains or brightness.

[SeeMoreDigital]

Thanks for the reply GodzilaAvenger,

The thing that really annoys me (and probably everybody else) about Dolby Vision on 4K UHD disc is that the encodes are not all FEL. Indeed, I feel quite ripped off when I find out that the secondary stream on the disc has been encoded with a green video stream!