Originally Posted by Fou-Lu
I'd doubt if there's native support in any language for pretty much any audio/video codec.
Check out the matroska.org website. There's a structure on there, and appears to be a relatively large repository for libraries. I don't know what all of them are for, but it does have a jebml library which is listed as java source.
I'll have a look on there site when I get home, thanks.
I also came across VLCJ (or JVLC, I can't remember which) which seems like a Java library made by VLC, and VLC plays all the files I'd need it to so that could be a way forward too, but I'll see what matroska.org recommend to do.