How to convert Dolby Vision profile 7 to 8.1 on a Mac without re-encoding

UHD Blu-ray remuxes with Dolby Vision are profile 7: an HDR10 base layer, a second enhancement layer, and the Dolby Vision metadata (the RPU). Converting to profile 8.1 keeps the base layer and rewrites the metadata for a single-layer file. Done properly, the picture itself is never re-encoded, so there’s no loss of quality and it’s far quicker than any re-encode.

If you’re not sure what profile you have, start with how to tell if a file is profile 7 or 8.

First: check the enhancement layer

Converting to 8.1 removes the enhancement layer. If it’s a minimal layer (MEL), that costs nothing. If it’s a full layer (FEL), it may carry real picture detail, and once it’s gone it’s gone. Always find out which you have before converting.

The manual way

On any platform the lossless process looks broadly like this:

1. Extract the HEVC video stream from the MKV.
2. Use dovi_tool to convert the RPU to profile 8.1 and discard the enhancement layer.
3. Mux the new video stream back together with the original audio, subtitles and chapters.
4. Check the result has the right profile and nothing went missing.

It works, but it’s several tools, a lot of temporary disk space, and easy to get wrong across a whole library. Lose track of a subtitle track or a chapter list and you won’t find out until you’re watching.

The Remux Doctor way

Remux Doctor does the same lossless conversion as a single fix.

1. Drop in files or a folder. Each one is examined and explained in plain English.
2. Set your target. Choose which Dolby Vision profiles you allow. If you only want 8.1, every profile 7 file is flagged with the fix it needs.
3. Look at the enhancement layers. Profile 7 files are sampled so you can see which have a minimal layer and which have a full one. Full layers are never converted automatically. They’re left for you to review, one by one.
4. Fix. Convert a single file, or use Fix All to run every file’s fixes in order, one file at a time.

Results are written as new files and checked before they’re kept. Your originals stay where they are unless you’ve turned on the optional setting to move them to the Trash after a verified fix. If you want a way back, you can save the enhancement layer and restore profile 7 later.

CM v4.0 metadata

While you’re there, you may see files carrying CM v4.0 content-mapping metadata alongside the older CM v2.9. If your target says you want v2.9 only, Remux Doctor can remove the v4.0 metadata, again without touching the picture.

Will it play on my TV?

Remux Doctor doesn’t make promises about how any device or player handles a file, because setups vary too much. It checks files against the target you choose and tells you, factually, what’s in each one.

Examining and checking files is free, and so is fixing your first three files, so you can convert a film and check it on your own setup before paying. Every other fix, Fix All and watched folders that fix automatically are a one-time purchase with Family Sharing. Remux Doctor is coming soon for Macs with Apple silicon running macOS 15 or later.