Converting Dolby Vision Profile 7 to Profile 4

[Dalaibot]

Hi,

Sorry, I'm new to these forums , but stumbled accross this (https://forum.doom9.org/showthread.php?t=183292)thread, where topjes talked about using MakeMKV, dovy and Mkvtoolnix to convert 4k Blu-ray rips (which are always profile 7) to profile 8 or profile 4.

Since my current setup only supports profiles 4 & 5 I've searched high and low for a method to convert my rips to Dolby Vision profile 4 and I've used all the above-mentioned tools previously, but cannot work out how to strip out the HDR10 baselayer from the BL, EL + RPU in such a way that makes the end file recognised as profile 4 by MediaInfo.

Has anyone done this before? Any help would be extremely appreciated.

[von Suppé]

2.) "remux" it with mkvtoolnix with original EL+RPU (extracted from UHD Remux) into dual track dual layer Dolby Vision Profile 7. Then I can also put this file into MakeMKV and create single track dual layer Re-encoded BL + original EL + original RPU Dolby Vision Profile 4.

I don't think importing a dual track dual layer Profile 7 mkv into MakeMKV will give a Profile 4 result. What MakeMKV does is interleaving BL and EL into one videotrack, making it single track dual layer. Profile will remain 7 though.

I have no experience with converting DV Profile 7 to DV Profile 4. I understand this profile 4 has SDR baselayer. I highly doubt that you can extract a HDR-encoded baselayer from Profile 7 "recognised as" SDR. You can't take an apple out of a basket in such a way it turns into a pear, my guess...
Additionally, even if you'd remap tone and recode BL, I don't think you can combine with native EL. Which is still HDR in the first place, but also because of AV sync issues mentioned in the aforementioned thread.

Profile 5 uses proprietary colorspace, so I don't think freeware can be used for converting (BL only, that is).

Maybe other people will chime in.

[Dalaibot]

Thanks for the response. I think you're probably right, but I'll spend some time over the weekend seeing what I can come up with in respects combining the rpu from the EL and injecting it into various transcoded/tonemapped variations of the baselayer and see if I can get it recognised as profile 4 and maybe even playable...