HDTVs and MKV videos?

[kyosak]

Well I just bought this HDTV (Samsung C6300) and I've been trying to take advantage of its media features.
I hook up my external HDD and find that it can indeed play my MKV video files.
It's slightly annoying because I have to use a program to extract subtitle files out of the MKV and convert them from .ass to .srt but other than that, it's been fine.

However, there are some MKV files that refuse to play. It's always either "unsupported video codec" or "unsupported audio codec."
What's the quickest way to diagnose my problem and convert the video/audio codec for my files?

[Tythera]

I'm not sure if this will end up being specific enough with what it calls codecs but it's worth a try. MKVtoolnix: http://www.bunkus.org/videotools/mkvtoolnix/

If you run MKVinfo and then view the file you should get something like below.

Spoiler: show

http://imgur.com/ynUBj.png

I'd start by checking a file you know works and one that doesn't work and comparing the codec lines in both the audio/video.