I get artifacts when using ffdshow dxva when playing certain .mkvs. Sometimes there are green bands along with it. Everything plays fine when you disable gpu acceleration
I tried using another media player to see if it was ffdshow but the artifacts remained when gpu acceleration was enabled
Here is a video file that I have artifacts on: http://www.filesonic.com/en/file/11932245/Suzumiya_Haru...
I'm guessing its my video card thats causing it, have a ASUS 5850. Running CCC 10.8
I know you tired another Media Player, but have you tried VLC? It hadnles my mkvs really well. I used to have problems watching subs in other media players, and VLC seems to be the only one that works well for me.