Preserving HDR/DV information when editing

[borisanddoris]

Maybe this is a dumb question, but I want to take a 4K UHD disc I've ripped, and re-edit a movie to conform to a different cut that does not exist in HD or UHD.  Yes, I'm going to be secretive because I want it to be a surprise and also, I'm not sure how well its going to go.  Either way, I want to preserve the color information best I can, just need to re-cut the film.  Is there a way to do this when importing the video stream into Adobe Premiere?  If not, what's the best way to keep the video as faithful to the HDR/DV transfer as possible?  Thanks!

[PDB]

Maybe this is a dumb question, but I want to take a 4K UHD disc I've ripped, and re-edit a movie to conform to a different cut that does not exist in HD or UHD.  Yes, I'm going to be secretive because I want it to be a surprise and also, I'm not sure how well its going to go.  Either way, I want to preserve the color information best I can, just need to re-cut the film.  Is there a way to do this when importing the video stream into Adobe Premiere?  If not, what's the best way to keep the video as faithful to the HDR/DV transfer as possible?  Thanks!

Take my advice with a grain of salt, others might know better and sorry if I'm saying things you already know.

Well DV is out all together. Nothing will read DV at the moment. Not AP, Final Cut or even Resolve. Dolby has proprietary tools for DV and they aren't sharing. You can't convert DV to HDR10, not until someone figures out a hack.

AP should be able to do 2020 and 2100 HDR but it makes it very difficult on you. It has a list of requirements and problems that make it a real pita.


Some Requirements:
You need the latest and greatest copy of AP. AP has been doing HDR for like 8 years but has always kind of screwed it up until recently. The 2021/2022 copies seem to be better at HDR.

You need to set your timeline to HDR, you need to set you scopes to HDR and you need to sometimes interpret you footage as HDR when ingesting. Sometime AP can't identify the footage as HDR when it is.

You need to input footage in a HDR friendly editing format and container. AP will read H264 and H265 but it never edits those formats very well, especially in a MKV. Since UHDs are H265 AP kind of chokes on that especially in 4K. Having the format in HDR PR444, MXF, other Image sequences, etc might make it easier.

Some Problems:
The major problem that I am aware of is that AP is still built around 709. The monitor out, unless you using external cards, is stuck in 709. Doesn't matter if you have a HDR monitor, HDMI 2.1, etc. Any ingesting of HDR footage into AP is interpreted in AP as 709 via LUTs and the like so you can view it on a 709 monitor. You can put HDR footage in and get HDR footage out (also very difficult) but in AP that footage is 709. That is unless something has changed recently.

Second I think some effects don't work correctly when outputting into a HDR friendly format. Not sure which but that's what I've heard.


The sad part is Resolve does all the colorspace work, much, much better but man I hate editing using it. AP just needs a serious modernization by making it easier to deal with different format, colorspaces, etc .Hell even AE from the same company does better with colors.

What is the format of the footage you are inputting in AP?

[borisanddoris]

You know this is all moot now I think. The disc was encoded such that all I need to do is reorder the m2ts files with mkvtoolnix and create the desired cut. At least I think I got it to work. Star Trek VI is the film in question. My desire was to recreate the 1992 cut of the film from LaserDisc which is not present on the disc. The directors cut is included but it still has some further changes. By reordering the files though, I think the 92 cut can be recreated. I have to rerip the disc though as some files somehow became corrupted. In the end, I hope to present a guide on how to do it and include both LD and the 1999 DVD audio which would conform to this unique cut of the film and the one I know best after years of play of the LD.

[PDB]

Love to see it when you are done. I'm a big fan of 6 but not so much of the revision to the dc.

[borisanddoris]

I was able to successfully recreate the 1992 LaserDisc cut of the film (also on the 1999 non-anamophic DVD). All one needs to do is edit the playlist file and then rip with MakeMKV. I'm in the field now and not at the main machine but once I get back to HQ, I'll create a guide. It worked like magic and really makes me wonder why Paramount chose not to also include that cut: all the data is there on the disc...just need to tell it which order to play in. The way they crafted the m2ts files almost makes me wonder if they were going to do it and someone said nope at the last minute. Finally, no more GONGS.

*EDIT: No more gongs but still time for cleaning chronometers and Scooby Doo ending!

[babouin]

Good to know you figured it out.
To add to the conversation and possibly help someone in the future, I can share my own experience about a similar problem. In my case I had to edit multiple HDR10 files into one single output file. How I did it might not be ideal but it worked.

That was back in late 2020, I gave up entirely on doing it with Premiere and instead moved my project to Davinci Resolve Studio. I remuxed all my files to MP4 while keeping the original HEVC from the different 4K blurays and was then able to import everything in Resolve. Surprisingly, with the native HEVC Hardware decoder included in Resolve Studio, everything played smoothly enough to do all the editing I needed.

Keeping the original colors and HDR grading required me to set Resolve to bypass all color management. At the export phase I exported it into a DNX HR 10bit file ignoring HDR entirely and then reapplied the HDR10 metadata when encoding the final file using x265.
I was able to fix the monitoring view by applying a BT2020 to BT709 LUT in Resolve settings.

All the files had the same HDR10 metadata except for the "Maximum Content Light Level" and "Maximum Frame-Average Light Level", for these I kept the highest values of all my files and used these. I think there is a tool out there to calculate it and that would probably have been more accurate. Those are also optional and I could have discarded it entirely, some of my sources did not even included these.

To my knowledge, the output colors were identical to the sources.


For Dolby Vision, there is lack of tools when it comes to editing but it should just work by cutting and merging files together. Some Dolby Vision profiles are embedded straight into the HEVC stream and others (like 4K blurays) would require keeping both the base video stream and enhanced layer stream in sync.
There are also unofficial tools online to manipulate raw Dolby Vision data, it might be possible to keep Dolby Vision even after editing and re-encoding the file but that would be very tedious to keep everything frame accurate between two softwares.

[allldu]

At the export phase I exported it into a DNX HR 10bit file ignoring HDR entirely and then reapplied the HDR10 metadata when encoding the final file using x265.

Hi babouin. An interesting guide for sure! I am trying to work on some similar project, and I have a question. How do you reapply the HDR 10 meta data after you exported it into DNX HR?

[babouin]

At the export phase I exported it into a DNX HR 10bit file ignoring HDR entirely and then reapplied the HDR10 metadata when encoding the final file using x265.

Hi babouin. An interesting guide for sure! I am trying to work on some similar project, and I have a question. How do you reapply the HDR 10 meta data after you exported it into DNX HR?

Here's the command I used recently on a similar project:
ffmpeg -hide_banner -loglevel error -i dnxhr.mov -f yuv4mpegpipe -strict -1 -pix_fmt yuv420p10le - | x265 --y4m - --preset slower --crf 17 --profile main10 --range limited --hdr10-opt --max-cll "1000,400" --master-display "G(13250,34500)B(7500,3000)R(34000,16000)WP(15635,16450)L(10000000,1)" --colorprim bt2020 --transfer smpte2084 --colormatrix bt2020nc -o output.hevc

See the following two links to know how to properly set max-cll and master-display. You can get the original values using MediaInfo on the original file that contained HDR10 metadata.
https://x265.readthedocs.io/en/master/cl...er-display
https://x265.readthedocs.io/en/master/cl...on-max-cll

My example is based on the following values from MediaInfo:
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 : 400 cd/m2

The final result will be an HEVC bitstream with HDR10 metadata embedded in it. There are also ways to set at the container level if your final output is not HEVC.

[BDgeek]

I'm coming late to the party (unfortunately I was away for a few months, and hope to be back for good) and what I'm about to suggest may sound really rough (and it is), but I was able to edit UHD video while keeping HDR10, HDR10+ and DV using tsmuxer.

Yes, the editing is by timestamp only and no video support, but if one maps out the edit points, one can split and glue back together the video segments with no loss in HDR information at all.

[borisanddoris]

Is it frame accurate? I always thought it could only split and cut on key frames? If it is frame accurate, that would be super helpful!