Hi. Have you selected the DTS soundtrack on the DVD? If so, do you get audio? If so, then the DTS is being decoded.
If you aren't getting audio when you select the DTS soundtrack, then we might be able to get it working for you. Your DVD player and/or TV might be capable of decoding it for you. So, if you aren't getting DTS audio, please let us know the model numbers for your DVD player and TV, and we'll try to help you out.