Subler? Change profile for Apple TV and how to optimize?

[DaGrandMastah]

2 Questions. I'm converting some mkv files to m4v to play on my apple tv 3 but i'm not sure on the following:

1. Should I automatically change the profile to main @ 3.1 since it's playing on an apple tv 3? It loaded up as high @ 4.1

2. How do I optimize the file? Do I first convert the file to m4v and then optimize? What exactly does that do?

[Pyromonkey83]

Originally Posted by DaGrandMastah

2 Questions. I'm converting some mkv files to m4v to play on my apple tv 3 but i'm not sure on the following:

1. Should I automatically change the profile to main @ 3.1 since it's playing on an apple tv 3? It loaded up as high @ 4.1

2. How do I optimize the file? Do I first convert the file to m4v and then optimize? What exactly does that do?

1. Main @ 3.1 has a resolution limit of 720p. The Apple TV 3 supports up to High or Main @ 4.0 levels, but I do in fact believe you will be fine by leaving it at High @ 4.1. iTunes will end up dropping or compressing certain video and audio packets for streaming to support the ATV better but it should still work fine. At the very most I would say just change to High @ 4.0.

2. After you add the mkv to Subler and select all of your settings, add it to your queue. In the queue window at the bottom there is a small arrow that opens a mini menu. In here you will find a checkbox to "optimize" before you start your queue. This does some fancy stuff (I have no idea what it does technologically speaking) that causes your videos to be optimized for web streaming. If you make 2 files, one optimized and one not, you will find that the optimized version starts playback much quicker and does not have a long load time at the beginning of the movie or when changing chapters.

[DaGrandMastah]

Originally Posted by Pyromonkey83

1. Main @ 3.1 has a resolution limit of 720p. The Apple TV 3 supports up to High or Main @ 4.0 levels, but I do in fact believe you will be fine by leaving it at High @ 4.1. iTunes will end up dropping or compressing certain video and audio packets for streaming to support the ATV better but it should still work fine. At the very most I would say just change to High @ 4.0.

2. After you add the mkv to Subler and select all of your settings, add it to your queue. In the queue window at the bottom there is a small arrow that opens a mini menu. In here you will find a checkbox to "optimize" before you start your queue. This does some fancy stuff (I have no idea what it does technologically speaking) that causes your videos to be optimized for web streaming. If you make 2 files, one optimized and one not, you will find that the optimized version starts playback much quicker and does not have a long load time at the beginning of the movie or when changing chapters.

Thanks for answering. That basically clears it up. No point in me messing with the files then. I'll just leave hte profile as is and make sure everything is optimized.

[mic j]

Originally Posted by Pyromonkey83

This does some fancy stuff (I have no idea what it does technologically speaking) that causes your videos to be optimized for web streaming.

Just for the sake of understanding, the optimization is the moving of a small packet of information, called the moov atom, from the end of the file to the beginning of file. The moov atom contains playback information. When it's at the end, your player will not know how to play the file until it reads the atom. Moving it to the beginning, allows the player to have that information before the file is entirely loaded, thus speeding up the process. Of course, there is a reason the moov atom is normally placed at the end. If you modify the information (metadata), you only need to re-write moov atom. If it is placed at the beginning, you have to re-write the whole file (everything is shifted) which is a little slower. So far, though, I have found the re-write time of an optimized file to be very tolerable. Schools over.