How do you edit Anime videos on Sony Vegas Pro 11?

[KurugayaUchiha]

So I 've been trying to do this for a while and I keep encountering the same problem. All my anime that I wish to edit are always in MKV. and Sony Vegas Pro 11 doesn't use that video format.
I've been looking for videos and forums about how to fix this problem and the most common answer I find are video converting methods. I just tried using one but it didn't help, the one I used was avidemux.
So if anyone can help me either understand how to the converting method and video converting program that works or show me an easier method to convert.

[RTW47]

follow this path young padawan.

[KurugayaUchiha]

follow this path young padawan.

Thank you! Now I finally moved forward a little bit. Now the only problem is that the video is all green.

[RTW47]

for 10-bit encodes. (which most likely you have) you need to convert instead of recontainering source files. (i.e jump to section B)

[KurugayaUchiha]

I've figured it out thanks!