No sound when playing MKV movie on my WDTV HD Media Player

I got myself a used Western Digital HD media players (first generation).  I was not aware and did not really care for the differences between the first generation and the second generation media players.  All I really wanted was to play movies.  After watching a few movies with no problems, I got myself a 720P movie with an amazing sound quality.  I stared watching it and all I got was a movie without sound.  That did not make sense.  I was able to play that movie on my PC with no problems.  After some digging around on the internet, I found out that the first generation of WDTV HD media players lacked the DTS decoder.  DTS is a sound format that comes with a very high sound quality.  Sure enough, after looking up the properties of the movie I was playing, it did state DTS for audio.  That's not good.  I want to watch my movie.  I really thought of playing the movie on my PC to get the sound and somehow synch it with the video on my WDTV HD media player but knowing myself, I can never do that ;).  There is got to be a way.

Since I bought this box second hand, I can't return it and I'm not going to go buy the second generation media player nor I will buy the WDTV Live HD media player.  There is got to be a way.

According to some forums out there, the first generation includes an optical output for digital audio which simply outputs raw audio.  For that to work, I would need a decent amp that decodes DTS and takes in an optical audio input.  I don't have this kind of amp and I don't think I want to get an amp just to play this movie.  There is got to be other ways.

One way I found was to convert the DTS audio in the MKV movie to a more supported format (Dolby Digital or DD).  An unofficial format of DD is the AC3 audio codec which implements DD's specification and is widely used by DVD and media players.  The tools I used was "Popcorn MKV AudioConverter" that I found on  It's free and easy to use.  Such an amazing tool.  It takes the MKV file as input and does it thing by converting the DTS sound track to AC3 and then remixes it back into the MKV file.  The input file is not modified but rather a new output file is created with the same name.

Once the conversion was done, I was able to play the movie on my WDTV HD media player with no problems.  Of course there might be some sound quality decrease but I was still getting amazing sound through my surround system (Dolby Digital 5.1).