Unsupported audio format in MKV file on LG 47LW5600 TV.

I have an LG 47LW5600 TV which I am connecting an external hard-drive to in order to play video files. I've come across an MKV file that I'm getting an "Unsupported audio format" error with. The file contains DTS audio. I'm assuming that I will need to convert the DTS audio in the file to another format and remux the MKV file with the converted audio file. What is the simplest course of action to achieve this?