How to add a Dolby Digital Plus track to a TrueHD remux, without losing the original
Why you might want a Dolby Digital Plus (E-AC-3) track alongside lossless TrueHD or DTS-HD audio in a 4K remux, and how to add one on a Mac while keeping the original.
A good remux keeps the disc’s lossless audio: usually Dolby TrueHD (often with Atmos) or DTS-HD Master Audio. That’s the best the film sounds, and you should keep it. But lossless tracks are big, and not every part of every setup can decode them. A common answer is to add a second, compatible track alongside it: Dolby Digital Plus, also known as E-AC-3.
Why add a track instead of replacing one
Converting the lossless track and throwing the original away is a one-way trip. Adding a Dolby Digital Plus track next to it means the file carries both. Whatever is playing the file can use the lossless track where it can, and the Dolby Digital Plus track where it can’t, and you haven’t lost anything.
What to know first
- The new track is lossy. Dolby Digital Plus is compressed. It’s there for compatibility, not as an upgrade.
- It won’t carry Atmos. The new track is made from the lossless audio’s channels, without the Atmos object information. Keep the original track for that.
- Only the audio is encoded. The video should never be touched by this kind of fix.
The manual way
Typically: extract or decode the lossless audio, encode it to E-AC-3 with FFmpeg, then mux the new track back into the file alongside the original, set its language and name, and check the track order. It’s routine once you’ve done it, but it’s fiddly to do over and over.
Doing it with Remux Doctor
Remux Doctor makes it a single fix.
- Drop in your files. Each is examined, with its audio tracks explained in plain English, including whether they carry Atmos.
- Include Dolby Digital Plus in your target’s audio. Files that don’t have a Dolby Digital Plus track are flagged.
- Fix, one file at a time or all at once with Fix All.
Remux Doctor encodes the new track from your lossless audio and adds it to a new file next to the original. Your original audio track stays, the picture is copied exactly, and the new file is checked before it’s kept.
Examining your library is free, and so is fixing your first three files; after that, fixes are a one-time unlock with Family Sharing. Remux Doctor is coming soon for Macs with Apple silicon running macOS 15 or later.