I'm running PS3 Media Server to stream movies to my Xbox 360. I typically have the movies in the mkv container, but unfortunately the xbox does not support 5.1 sound in mkv. I've used handbrake to convert to mp4 which regains the 5.1 sound, but I'm pretty new to handbrake and it is hurting the video quality. The resulting files are smaller, but I don't care about file size as long as I can stream it properly. How do I convert my mkv files so they will have 5.1 sound on my xbox without significantly changing the video quality?