The DTS Coherent Acoustics standard (ETSI 102 114 v1.2.1), as published by the ETSI, is available here (look for DTS Coherent Acoustics).
Right now, I am concentrating on finishing the implementation of the core part of the specification. The library should however already be quite useable.
A few things are still lacking there but they should mainly affect low-bitrate DTS streams which don't seem that common anyway (some of the missing things are: Joint channels coding, Dynamic range, etc… - see the TODO file).
There might also be quality issues, but for some early code it does seem pretty decent to me.
None of the extensions (extra channels, 96/192kHz sample rates) have been implemented (and unfortunately the public standard provides only minimal information on them).
Current release is libdca-0.0.6.tar.bz2
The latest libdca source code can always be found in the GIT repository:
$ git clone https://code.videolan.org/videolan/libdca
For support information, have a look here.
A libdca-devel mailing list is also available.
If you use libdca in another project, let me know!
Some very good samples are available on the swedish radio website.