I keep getting really choppy playback from 720p MKVs using NitoTV. I’ve fully updated everything including the latest 4.4 ATV flash release. I’m streaming from a 27" i5 quad-core iMac with an Airport Extreme all in the same room as my Apple TV 1G. I checked to make sure the MKV is within the constraints: 5 Mbps, maximum resolution 1280x720 @ 24fps. It’s just under those requirements.
I tried these steps already and none of them have helped:
"You may try the following.
1. Disable the 'Apple H.264' option through the Maintenance --> Settings menu.
2. Change 'File Playback Mode' to Quicktime through the nitoTV --> Settings --> General menu.
3. Play the file through the nitoTV --> Files menu.
As the movies starts, press the play/pause button and let the blue 'buffer' bar fill up. Once the bar fills completely press play/pause again to start the movie."