H.264 Profile 4.1/4.0 and Muxing/Buffering

Discussion in 'Apple TV and Home Theater' started by MrBlobby, Aug 23, 2013.

  1. MrBlobby macrumors newbie

    Aug 19, 2013
    So I'm hoping someone here may be able to help.

    Long story short, I have remuxed a large number of MKV files to MP4, via Subler, for use on my Apple TV 3. Unfortunately, at the time I didn't understand that the ATV3 (currently) does not support Profile 4.1 for video, only 4.0. So all of these mp4s are profile 4.1 and won't stream well to the ATV3 (they buffering endlessly, like 30 minutes or more just to start playing a two-hour movie).

    Alas, Subler doesn't support any option for muxing profile 4.0 video, only 4.1 and/or 3.1 Main and High. And remuxing at 3.1 (which supports 720p but not 1080p) wouldn't work either as I'm dealing with 1080p source material.

    So it seems i know have a bunch of mp4 versions of movies that are useless, on the Apple TV anyway. Aside from reencoding all of the files via Handbrake to profile 4.0, does anyone know of any other solution I may be missing?

    Thanks much to anyone who has any insight.
  2. mic j macrumors 68030

    Mar 15, 2012
    Try taking one of your problem files and use Subler to "Optimize" it. It only takes a couple minute to try it. Worth a shot.
  3. MrBlobby thread starter macrumors newbie

    Aug 19, 2013
    Yeah, I tried that. Unfortunately ATV3 just doesn't support 4.1 It's fine on smaller files, but the larger the movie file the worse the lag and buffer gets, even with optimization. :mad:
  4. Cinephi1e macrumors regular

    Jul 19, 2012
    Northwest Ohio
    I have not tried this myself, but someone suggested the following in another thread. You may want to try it.

  5. mic j macrumors 68030

    Mar 15, 2012
    From my reading, the difference between 4.0 and 4.1 is minimal (mostly a difference in maximum bitrate) and many people think the aTV3 should handle a 4.1 fine. Have you done an analysis (using Media Info or a similar tool) to check your maximum bitrate? The size of the files has nothing to do with the start of streaming as the movie should start once the aTV has buffered a certain amount of data (and that's not a lot, maybe a gig or so). I have a 22GB mp4 that streams fine. That's why I thought of needing optimization. What you are experiencing is very common with large unoptimized files as the movie won't start until it has the moov atom data located at the end of the file. Optimization moves that to the beginning and the movie starts right away.

    Anyway, I don't have any other ideas, so good luck!
  6. kryten2 macrumors 6502a

    Mar 17, 2012

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