Which uses less iPod battery, H.264 playback, or MPEG-4 ?

Discussion in 'iPod' started by motulist, Jan 9, 2008.

  1. motulist macrumors 601

    motulist

    Joined:
    Dec 2, 2003
    #1
    I'm converting videos for my new iPod Classic 80 GB and I want to know which format uses less battery life. H.264 creates smaller files which theoretically might mean it accesses the disk less and saves battery, but H.264 is probably (?) a more complex codec which theoretically might mean more processor intensive decoding and thus requires greater battery usage.

    So at the same visual quality, does playback of H.264 or MPEG-4 take less battery? (I'm not too concerned about video file size on my 80 GB iPod.)

    I'm using iSquint to convert my videos and I want to know if it's worth using the H.264 option which takes much longer.
     
  2. kuebby macrumors 68000

    kuebby

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    Jan 18, 2007
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    #2
    I would say whichever has the smaller file size because accessing the HD is the main use of battery life.
     
  3. Dustman macrumors 65816

    Dustman

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    Apr 17, 2007
    #3
    Anyone feel free to correct me if i'm wrong.
    H.264 is a more complex format, thus (atleast in my head) it would use more power. Im not sure if this is true because the iPod has hardware dedicated solely to decoding H.264 content. That being said, Mpeg-4 is probably the best decision anyways because of the superior video quality and flexability. H.264 just takes waaay too long to encode, and since the only real upside is saving a couple MBs, id say just keep doing what your doing and encode in Mpeg-4.
     
  4. wetnap macrumors member

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    Jun 7, 2008
    #4
    it requires slightly more to decode, not sure how much the difference really is on an ipod. apple should have told us.

    as for encoding speed, its not much different these days. encoding using hand brake is very fast, we aren't talking encoding h264 hd here, but low res for ipod video, easy as pie for todays processors. mpeg4 doesn't have superior video quality..
     
  5. elppa macrumors 68040

    elppa

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    Nov 26, 2003
    #5
    H.264 is MPEG 4 (part 10).

    What do you mean by MPEG-4?
     
  6. motulist thread starter macrumors 601

    motulist

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    Dec 2, 2003
    #6
    The designation of H.264 vs. MPEG-4 is straight from Apple.

    http://www.apple.com/ipodclassic/specs.html
     
  7. mosx macrumors 65816

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    Mar 3, 2007
    #7
    H.264 IS MPEG-4.

    With that said, H.264 is higher quality than the other MPEG-4 format the iPod supports. Higher quality video at the same bitrate.

    H.264 video doesn't take very long to convert. Even on slow systems it'll take about real time, which isn't bad. Set up a few videos to encode while you sleep.
     
  8. motulist thread starter macrumors 601

    motulist

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    Dec 2, 2003
    #8
    Hahahaha :eek: :p :D

    Apparently your definition of a slow system which still gets regular usage is very different than my definition. I still regularly use a blue and white G3 powermac, but I wouldn't even attempt video transcoding on it. Everyday I use a G4 grey and white powermac which encodes H.264 MUCH slower than real time. And the fastest computer I own, a 1 ghz powerbook G4 is lots faster but still slower than real time at encoding H.264. The 1 ghz powerbook is still completely adequate for all standard computing tasks, but H.264 encoding is very slow.

    Anyway, the question is if the greater CPU intensity which is required for playback of H.264 uses more battery than the larger file size MPEG-4 playback that requires more disk activity.

    Actually, the question is even simpler than that. Here's the question. Regardless of the reason, which format uses up more battery during playback for comparable image quality files?
     
  9. hazmatzak macrumors regular

    Joined:
    Apr 29, 2008
    #9
    The video codec for "just plain MPEG-4" is in fact MPEG-4 Part 2, as opposed to Part 10 for H.264/AVC. I can see why they gloss over that detail, since it's just too complicated.

    As to the original question, which uses less battery power, Part 2 or Part 10, I suggest you do a test with the kind of video that you actually watch. If I had to guess, the battery difference is minimal either way. So if you're constantly transcoding new content to watch and then discard, use Part 2 ("MPEG-4") since it takes much less time. But if you're planning to save the content, Part 10 (H.264) is the better standard and you may have better luck finding compatible players in the future.
     
  10. wetnap macrumors member

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    Jun 7, 2008
    #10
    well its a technicality. we know its mpeg4 part 10, but frankly no one calls it that. in common usage if you say mpeg4 no one is going to think you are talking about h264. especially when in the context of comparing h264 vs the mpeg4 we are talking about. i'm on a budget pc with an e2200 intel, takes about 15 minutes to encode a film in h264 for ipod. the decode penalty is probably not as great as its the h264 baseline profile. course if you encode at higher than 320x240...then i think ur battery will give out pretty quick.
     
  11. Dagless macrumors Core

    Dagless

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    #11
    What?:eek:

    Series 1 of the Office took 24 hours to encode all 6 episodes. Don't know if there was any speed limit from the DVD but it was sloooow. My C2D iMac is more real time.
     
  12. wbeasley macrumors regular

    wbeasley

    Joined:
    Nov 23, 2007
    #12
    How about video size?

    It's probably very hard to compare battery usage on video codecs but another thing to think about when encoding is video size.

    If you encoded (cropping if necessary) to the device's native screen size it would probably require less processing power to playback. 640x480 on iPod Classics, unless you are going to connect to a TV, is probably going to cost you more battery to scale down to native display size.

    I encode at fairly low bit rates (300 kb video) and get same sized files for both Touch and Classic devices. Touch I encode at 480 x whatever, Classic gets the 320 x whatever. Full screen downscaling of 4:3 video on the Touch probably uses more battery too. Really only use that for titles and credits.

    And add in screen brightness to the equation... and probably volume... and button happy users...

    Guess we are lucky today's batteries last a lot longer than they used to! (Sometimes I do wish the Touch was another 1mm thicker so the battery would hold on a bit more).

    Can't please everyone :)
     
  13. wetnap macrumors member

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    Jun 7, 2008
    #13
    i'm sure the next gens battery life will increase quite a bit.
    sonys already managed to squeeze about 9-10 hours of video on their walkmans, so its possible without making the units larger. course they only support 320x240 and nothing else.


    and yea bitrate, if you have a high bitrate video it takes more to decode it. simply more data.
     
  14. wetnap macrumors member

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    Jun 7, 2008
    #14
    its probably better to rip the dvd first.
    wear and tear on the drive for one, and i'm not sure but i guess it might be faster.

    and no,its not a dvd speed limit. it takes maybe 10 minutes to rip a dvd. its read rate is far faster than any encode. i guess you encoded full dvd resolution and or used 2 pass to take that long right?
     
  15. alphaod macrumors Core

    alphaod

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    Feb 9, 2008
    Location:
    NYC
    #15
    h.264 is a compression format; MPEG-4 is a container.
     
  16. motulist thread starter macrumors 601

    motulist

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    Dec 2, 2003
    #16
    Read the thread.
     
  17. wetnap macrumors member

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    Jun 7, 2008
    #17
    you can scream that from the top of the mountain but it won't make a lick of difference.
    ;)
    the reality is the terms have come to mean what they mean from common usage. and thats all that matters in the end.

    you might as well go around screaming at people whenever they fail to mention that mp3 is actually mpeg-1 audio layer 3.
     

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