In H/W decoder:
If you want to play DTS while using HW decoder, goto Settings 》 Decoder & Enable software audio. By this the Video will be rendered by H/W decoder and audio will be rendered by S/W decoder. (If you want to use it for only particular files when you playing the video, press on audio selection button & Enable S/W audio. S/W audio will be used temporarily for that file.)
In H/W+ & S/W Decoders:
There is no special setting is required.