What are the iPod Touch's H.264 playback capabilities?

Discussion in 'iPod touch' started by Wolfpup, Sep 17, 2008.

  1. Wolfpup macrumors 68030

    Sep 7, 2006
    (I use Windows right now for my conversions)

    I watch a lot of content from my S2 Tivo (so it's all 4:3). I use an old version of Videora because it's the only thing I've found that actually works for me. (JUST found an open source program called "Mediacoder" that I may try too.)

    On my 5th Gen iPod, I have to stick to 640Kb/s or below, or it'll usually say it can't play it. I think it's really supposed to support up to 2500Kb/s, but possibly needs that "iPod atom" setting checked (which Videora lacks). I don't really know for sure, but I think I read something to the affect that the "iPod atom" limits the number of macroblocks in a scene-like the 5th gen can only have so many macroblocks, even if it can otherwise handle the bit rate (but I may be TOTALLY screwed up on all that).

    Anyway, I'm not sure that the Touch has that limitation, but I'm not sure what it's max bit rate is.

    Since it's a 480x320 screen, I guess the correct full screen size for 4:3 content would be 427x320. So, I'm guessing I can just manually punch that in, and then manually punch in a bit rate of (for example) 1500Kb/s...and if it doesn't have the same limitations as the 5th gen iPod, that should provide for high quality 4:3 content in the correct aspect ratio, using as much of the Touch's screen as possible. (And I assume if it's content that's letter boxed, and would thus be double letterboxed on the Touch, I can just tap the screen to zoom in and get it more or less full screen.)

    Does any of that sound right? I just ordered my Touch yesterday, so I'm anxious to get a show converted so I can try it out-hopefully with higher quality settings than my 5th Gen supports (not that the 5th Gen looks bad-it's always been quite impressive video quality IMO)!
  2. sandman42 macrumors 6502a


    Oct 23, 2003
  3. Wolfpup thread starter macrumors 68030

    Sep 7, 2006
    Thanks! Yeah, here's what it says:

    I don't completely understand why it says both 1.5Mb/s AND 2.5Mb/s, but it sounds like those capabilities are the same more or less as the 5th gen...except hopefully it doesn't have that macroblock limitation. I imagine this is just using it's CPU and/or GPU to decode stuff, so it might be more flexible than what the 5th gen's hardwired video decoder can do.

    If I end up switching back to a Macintosh as my main system (come on Macbook Pro updates!) I'll have to find all new programs to do this! Although I'll probably just buy Toast 9 and hopefully be done with it.
    Oh well, my trusty Prescott Pentium 4 is doing the job for the time being.
  4. gusto5 macrumors member

    Mar 24, 2006
    If you scroll further down there is a comparison chart, between the two and it looks like a copy-paste.
  5. Wolfpup thread starter macrumors 68030

    Sep 7, 2006
    So it does-no explanation about the differences that would limit it to 1.5Mb/s versus 2.5 though.

    Plus, I don't think the 5th Gen iPod ever listed the limitations it has in regard to macroblocks, or whatever its issue was. Hopefully it just isn't an issue on the Touch, which should make conversions a bit easier.
  6. Frogblast macrumors newbie

    Sep 17, 2008
    If you read it very carefully, you can sort of parse it out:

    1.5MB/sec for "Low Complexity version of Baseline Profile"
    2.5MB/sec for "Baseline Profile up to Level 3.0"
  7. Bonsai1214 macrumors 6502a

    Jan 15, 2008
    Penfield, NY
    a related question. no .mkv file support right? even though its the most common h.264 file type. oh well.
  8. Wolfpup thread starter macrumors 68030

    Sep 7, 2006
    Hmm...I guess Videora doesn't support bit rates above 768Kb/s, or else doesn't support the weird resolution.

    I'm trying this mediacoder, though the interface has been unresponsive at least once. I don't know if the Tivoed shows I'm converting will actually play on a touch or not! They don't work on my 5G of course.

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