alternatives to 480x480

Discussion in 'iPod' started by bepster, Nov 9, 2005.

  1. bepster macrumors member

    Joined:
    Oct 21, 2005
    #1
    Hi guys!

    well, I read this in a thread before but I can't find it anymore...

    I am converting some .avi to .mp4 for my iPod... of course I try to stay under 230400 pixel (480x480)!

    but not all movies are 480x480, actually very few... so has anybody figured out what the best is for 2.35:1, 1.85:1, 16:9 and so on??

    as I said, somebody posted it before... mh, can't find it...
     
  2. madmaxmedia macrumors 68030

    Joined:
    Dec 17, 2003
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    Los Angeles, CA
    #2
    In general, just remember that 480 x 480 = 230,400 pixels. So just re-size so that the total number of pixels is equal or less. For example, 640 x 360 plays back fine, and is exactly 230,400 pixels. I haven't tested all combinations, but for the most part this rule will work.
     
  3. dejo Moderator

    dejo

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    #3
  4. bepster thread starter macrumors member

    Joined:
    Oct 21, 2005
    #4
    the problem is that it has be devided with 16, right?
    so not all of your combinations work in ffmpegx
     
  5. dejo Moderator

    dejo

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    #5
    I'm able to pick whatever aspect ratio I want in ffmpegx. The resolutions do not have to be divisible by 16. I could choose 645 x 480, if I wanted.

    Anyways, here are the resolutions I believe you're interested in:

    640 x 360 for 1.78:1 (16:9; HD)

    640 x 345 for 1.85:1

    720 x 304 for 2.35:1
     
  6. snowmoon macrumors 6502a

    snowmoon

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    Oct 6, 2005
    Location:
    Albany, NY
    #6
    I recommend sticking to 640xY. I say this because if your height != the height as displayed then you will require scaling to output to TV which will rob the video of all that precious detail that you encoded with bits. Scaling on the PC has the advantage of being able to use one of several high-end algorithms that are probably better than what this codec chip can provide.

    This will be more of a moot point once we figure out how to do non-square encoding. This will allow use of proper height with ANY width in order to perserve the detail or save bits depending on the need.
     
  7. bepster thread starter macrumors member

    Joined:
    Oct 21, 2005
    #7
    thanks guys, this make's it a lot easier!
    but still strange, I get an error-message when not divisible by 16 and it wants me to change it!

    this is what it says:

    "Output video width is not divisible by 16
    You must define a width value for the encoded video which is divisible by 16."

    I am running the OSX version, maybe it's that...

    this thing about height is a good point, I'll keep that in mind!
     
  8. dejo Moderator

    dejo

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    #8
    Oops, yeah, me too. Just didn't get the error message until I hit the Encode button. Stick with 640 and 720 and you should be okay.
     

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