Advanced users are aware of the fact that there are various types of AC3 and DTS files: files ripped from AC3/AudioCD or DTS/AudioCD, files ripped from DVD in PES container, or files with different byte orders.
The AC3 formats supported by this software tool are: 8bit, 16bit big and low endian and SPDIF-padded AC3 (any number of bits and endian).
Regarding DTS formats, the application can deal with 8bit, 14bit big and low endian, 16bit big and low endian and with SPDIF-padded DTS (any number of bits and endian).
Furthermore, AC3File also offers support for MPEG1/2 Program Elementary Stream (PES) with AC3/DTS substream and for AC3/AudioCD and DTS/AudioCD format (IEC 61937 standard, SPDIF padded format).
http://www.free-codecs.com/