libdca is a free library for decoding DTS Coherent Acoustics streams. The code is written by Gildas Bazin and was based on the a52dec project. It is released under the terms of the GPL license.
The DTS Coherent Acoustics standard (ETSI 102 114 v1.2.1), as published by the ETSI, is available here (look for DTS Coherent Acoustics).
The original website is here: