Anamorphic 4:3 to 16:9 conversion

Discussion in 'DivX / XviD' started by Caligari9, Feb 2, 2009.

  1. Caligari9

    Caligari9 Member

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    Hi,

    After years of ripping DVDs and XVID conversion, something has just started to bug me.

    A PAL DVD is 720x576. If this contains an anamorphic picture, GK, MMEGUI etc convert to 720x400(ish), i.e. it gets squashed to look right.
    Isn't this removing some of the data from the picture? Shouldn't the resulting XVID be both wider than 720 and shorter than 576, say 830x466 (ish)?

    Am I missing something?

    Gary
     
  2. davexnet

    davexnet Active member

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    Perhaps they do it to keep it compatible with standalone divx/xvid
    dvd players. Dont they offer a way to override? If not,
    use something like virtualdub, and you get complete manual control.
     
  3. attar

    attar Senior member

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    My limited understanding of DVD versus AVI is:

    If the DVD is 720x576 and it's 16:9, then the standalone DVD player reads the flag and ensures that it is displayed at (720x16)/9=1024, so it's displayed at 1024x576 on a PAL TV (1024/576=1.777=16:9 (assuming it's a wide-screen TV).

    If you load the 720x576 mpeg source into VirtualDub and use the DivX codec at the default setting, the output will be an avi file with square pixels - play it with the likes of VLC and it's square screen.

    In VirtualDub, if you set the video output on the DivX codec to 'PAL 16:9' pixels - VLC will read the 16:9 AR flag and display it wide-screen.
    So nothings really lost.
    The number of pixels hasn't changed between source and output.
     
  4. Caligari9

    Caligari9 Member

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    But I think what you're talking about there is keeping an AVI with the picture anamorphic and using the PAR or DAR to tell the player how to behave.
    I'm talking about where the resulting AVI isn't anamorphic but has actual dimensions at a 16:9 ratio. This is how I prefer to have my videos, as anamorphic seems a bit pointless these days of HD and media streamers. I haven't burnt a single piece of video to a DVD in about 3 years.
     
    Last edited: Feb 2, 2009

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