Does ffmpeg normalise? That'd tend to increase the volume a little. If I'm re-encoding multichannl audio as multichannel audio I tend not to change the volume in the process. If you open the thd+ac3 extracted file with MKVMergeGUI it shows two individual streams, so it's kind of like the thd+ac3 are together in a container which is in turn inside the m2ts file on the disc. It shows a single TrueHD stream you can extract with a thd+ac3 extension, with a thd extension or with an ac3 extension, and that gives you both thd+ac3 together, just the TrueHD or just the AC3 respectively. I haven't worked with much TrueHD audio but if you open a Bluray title using MeGUI's HD Streams Extractor (a GUI for eac3to). So if a Bluray title was to contain only Dolby audio, it'd have to contain AC3 as it's one of the compulsory formats.Ĭhances are some of the budget model Bluray players only supported the compulsory formats, at least in the early days.

The newer formats, Dolby Digital Plus and DTS-HD High Resolution (lossy) and Dolby TrueHD and DTS-HD Master Audio (lossless) are all optional. BD-ROM titles must use one of those types for the primary soundtrack.

Plus for Bluray there's three compulsory formats all players must be able to decode.

Makemkv dolby atmos