[APPLE TV] Playing 720p/1080p MKV files on the AppleTV?

I am by no stretch an expert at video encoding but, since I got my AppleTV I have been on a quest for the best compromise in re-encoding "HD" content into a format that the Atv plays without lag and still maintains a good "HD" appearance. So I thought I would chime in on the best setup for me.

I have been using EncodeHD ( http://dcunningham.net/category/encodehd/ ) with the following Advanced Settings String:

-b 4000k -bufsize 1835k -s hd720 -qscale 1 -flags +4mv+aic -trellis 2 -cmp 2 -subcmp 2 -g 300 -ab 160k

Encode time can be long and I could probably optimize this string (any suggestors?) but, at a few hours encode, once it worked, i let it be. Hopefully this will help someone out as I did a good bit of searching to get to this point.

So how does the encode look with the above settings? Still HD quality, and playback is easier for ATV in XBMC? I have never heard of this program so I am not sure about what this does differently compared to a program like Handbrake...

I used Handbrake as well for a while but, I started having issue with some files not finishing the encode. With the Advanced Settings string I posted above, my results are as good as handbrake and my re-encodes are completing at about 95%+ - with the errors probably coming from CPU overuse while encoding.

If Handbrake hadn't been crapping out on me, I would have never quit using it. Today, I find EncodeHD a simpler, consistent solution for myself.

Yes, it is still HD quality (at least my eye thinks so, I know some here would argue). No to the XBMC HD question, I now just use Front Row for all HD content since it is able to play beefier HD files than XBMC. I hope a day comes when it can because I miss the xbmc interface.

I suppose we are talking about a stock AppleTv here?
The encoding settings depend on the codec (H264 or Xvid) not on the container (MKV, MP4, AVI). Best results are with H264 in general terms
First Generation and Second Generation have very different requirements
In general terms the 2nd generation plays 720p High profile at 3.1 just fine and should also play 1080p at 4.1 fine however there is no point bothering with 1080p as the device only outputs 720p
For 1st generation stock ATV the settings to be used for 720p are max level 3.1 max profile main (note it does not support all features of main see below) and ensure CABAC is off (ATV only plays AVCLC) no pyramidal b frames no weighted b frame no trellis as those make the file stutter
For max bitrate there are several currents of though handbrake sets those to 9500 with max buffer of 9500 a more conservative one sets both those parameters at 5000 as that would mean a peak of 10,000 and this is what Apple says the device can do
So if you want your 720p files to play make sure you set
cabac=0:b-pyramid=none:b-adapt=2:weightb=0:trellis=0:weightp=0:vbv-maxrate=5000:vbv-bufsize=5000
An alternative way to achieve the same is to set reference frames to a lower value than profile 3.1 has (5) for the Appletv setting this to 2 pretty much eliminates all issues without bothering about the picture buffer and max rate

I have purchased and installed the Crystal HD card, installed the needed drivers, and seem to have some difficulties in getting the most from the card in XBMC. Some movies only play stutter-free if I go to the Apple TV gen 1 settings menu and choose 1080i 50 hz, some best at 720p 50hz, some times 1080i, etc. Is there an ideal setting that I should be using here that I am missing because changing it constantly on a movie by movie basis is annoying?

(2009-01-21 07:08)UnisonRuss Wrote:  There is nothing we can do upgrading hardware wise, unless we all stripped the ATV bare and made our own box...that would be time consuming and costly though. it will have to be the developers that come up with a way to utilize the GPU somehow, or cut down on CPU usage even further through future updates.

Crystal HD is the best upgrade.

As for the OP he does not say whether he has crystal HD or not, nor does he say what the video stream is in the MKV file. If it happens to be h.264 and he has a crystal HD, which I doubt based on what he says, he might get better performance from an MP4 or other format. If it is h.264 and he has no crystal HD he sould get oe. I recently saw them on ebay at about 15 dollars. If it is h.264 with AC3 or MP3 audio he need only remux to an MP4 wich may seem more complex but far less time consuming.

thread is from 2009...

I'll make a new thread for this...On an earlier version of iOS and XBMC on the ATV2 I could play almost all 720p MKVs flawlessly... After upgrading the ATV2 to 5.2 and installing XBMC again, I'm having problems with all 720p MKV-movies. Someone said something about the newest iOS taking up too much RAM... Any ideas?