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."
1st Generation ATV does not like CABAC or certain other advanced digitization aspects of H.264. Did you run your file through MediaInfo Mac (or its updated program) to see the exact components?
You might post the results…
If it does contain these advanced components, try running the file through HandBrake with its 1st Gen ATV default to transcode it to CAVLC and other aspects of compatible digitization.
I found out that atv1 can’t handle high-profile AVC video. You can only play 720p MKVs that have a low or main profile AVC. I’ve already got an atv2, so it isn’t that big of a deal. But, I am going to sell it. I inherited it from a friend, but it’s useless to me if I can’t play 720p MKVs. I just wanted to see what it was capable of.
PS: I purchased an ATV2 late last year, but I still have not implemented it into my Home Entertainment system.
I continue to use my ATV1 in ways that may still be of value to you: for example with its internal hard disk, it was very useful on my 6 week trip to London. I loaded it up with content before I left. Also podcasts of NBC Nightly News and other shows kept me up to date. I also used Firefox to run BBC iPlayer to watch BBC content at will within one week of broadcast.
I use HandBrake (and to a limited extent an older program VisualHub) to transcode high complexity MKV’s back to ATV1 compatibility. On my new Lion Mac Mini mid-2011, these transcodes are very quick: 2X or 3X.