Originally Posted by pmcd
Are you talking about a high profile 720p m4v file ( such as one sees floating around the net in mkv format)? I thought the ATV 2g only supported main profile ( similar to the 1 g except you also 30fps support with the 2g model).
These are m4v files I've created using Handbrake, using an uncompressed Blu-ray 1080p rip as a source. The original rip was I believe done with an AnyDVD trial, and then passed through something else, such that it eventually ended up as a .ts file with just the Dolby Digital soundtrack (I forget some of the details, because I did that leg of it a while ago and have since been using MakeMKV for my more recent Blu-ray rips).
I created several flavors of the m4v file using Handbrake. A couple of different 720p encodes using the Handbrake nightly build's High Profile setting, as well as a 1080p encode. I could load the 1080p encode into iTunes, but it wouldn't let me sync it to my iPhone 4. All of my 720p encodes would sync to my iPhone 4 and appeared to play perfectly. Again, these were encoded in Handbrake using the "High Profile" setting, and not the older Apple TV setting. The A4 chip used in the new aTV, iPhone 4, iPad, and newest gen iPod Touch is believed to be able to handle higher bitrate content as compared to the older Apple TV.
As I said though, while these encodes appeared to play smoothly on my iPhone 4, I'm getting dropped frames or occasional judder (or something) when I play them on my new aTV. Letting the entire video get copied to the aTV's buffer does not change this.
One "advantage" that my aTV has over my iPhone 4 is that I can play my 1080p encode, but it has the same sort of playback issue (perhaps more frequently, I don't remember) and it's being downscaled to 720p, so there's no real advantage for me there anyway.
Last night I re-encoded my movie yet again, but this time used the old Apple TV setting. I did change the RF slider to 21 and set the video width to 1280. All other options were left as-is (again, this is using a recent nightly build of Handbrake). I tried that encode this morning but am still having the same playback issues.
I then went and played another HD movie trailer (for Alpha and Omega). I watched it very carefully and don't believe I saw any playback issues. I then tried the HD Avatar trailer again. Of note, both trailers streamed without needing to rebuffer this time (Avatar had paused midway through to catch up on the buffer both times I tried it last night), so either Apple's servers were getting hammered last night or my cable modem's downstream was slower last night than it was this morning. Back to the subject....the Avatar trailer appeared to play back perfectly smooth, with no "judder" issues.
So based on this *very* limited bit of testing, it seems like Apple's streaming HD content is not experiencing any "judder" issues, but my encodes are. But my encodes are also not displaying "judder" issues when played on my Acer Revo nettop or on my iPhone 4. Hopefully a lot of other people will run into this issue and complain loudly and Apple will manage to fix it in a firmware update. Or perhaps the Handbrake team will need to tweak something on their end or provide further guidance on how some of the settings should be configured when doing an encode to make the video more "compatible" with the new aTV. I'm wondering, could this be a 24 vs 23.97 type of issue, or related to the fact that the aTV sends a 720 60Hz signal to the TV?