mp4 or h.264 for battery life

Discussion in 'iPod touch' started by m-man, Sep 4, 2009.

  1. m-man

    m-man Member

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    mp4 or h.264 for battery life, which is better.

    from what i can gather mp4 encodes faster, and has a larger file size per same quality of h.264, but because mp4 is less compressed, i was thinking it would be better for battery life, since the ipod touch will have to work less to decode the file.

    what do you think?
  2. zDSpider

    zDSpider Member

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    mp4 is just a container, like mkv (or even avi for that matter). h.264 is more like a class. A "standard" (like MPEG-4 for instance).

    You can add a DivX/Xvid video stream and mp3 sound to an mp4 just like you could add x264 and AAC audio to an avi.

    Regarding compression, I highly doubt it would affect battery life. High compression leads to strategically placed (optimized) "blocks" on the picture and generally result in smaller files. But during the decoding process the software will have to deblock and smooth the edges of those blocks to "blend" in. They're all over the place. And the smaller they are the more they are. And the more they are the more the software has to work to find and smooth, find and smooth and so on.

    Lower compression would result in bigger blocks (and crappier quality) and the decoding process would have to average those blocks. Imagine two huge squares. One is red and one is blue. The software would put a PURPLE square in the middle. That's the average (mix blue and red and you get purple). This results in blurry images (hence the crappy quality) and more or less the same work as in a high compression scenario.
  3. JIMIneitor

    JIMIneitor Banned

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    i didnt know there was such a logic behind a video file

    as for battery, id say just lower the brightness, use earphones, and try not to play large files
  4. zDSpider

    zDSpider Member

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    Yeah, but it's more on the theoretical side. For all I know Apple could've added a blur layer on top and be done with it. As for large files, I don't really think it matters. Well, maybe on an iPod classic... The iPod touch doesn't have a HDD, it uses flash storage. So I'm thinking there's no caching involved.

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