https://github.com/foo86/dcadec
I discovered it yesterday from another forum. I believe the project is new. The first commit was in March 2015.dcadec is a free DTS Coherent Acoustics decoder with support for HD extensions.
Supported features:
Decoding of standard DTS core streams with up to 5.1 channels
Decoding of DTS-ES streams with discrete back channel
Decoding of High Resolution streams with up to 7.1 channels and extended bitrate
Decoding of 96/24 core streams
Lossless decoding of Master Audio streams with up to 7.1 channels, 192 kHz
Downmixing to stereo and 5.1 using embedded coefficients
Features not implemented:
Decoding of DTS Express streams
Applying dynamic range compression and dialog normalization
The developer doesn't consider it stable yet, but he says that it is close.
https://github.com/foo86/dcadec/issues/30
The license seems to be LGPLv2.1 ( https://www.gnu.org/licenses/lgpl-2.1.html )
I tested it on a DTS-HD MA stream and it seems to work. Maybe this could be merged into MakeMKV and then we wouldn't need the DLL file?