852 x 480 resolution - What's this?

Discussion in 'CloneDVD mobile' started by jasondunn, Mar 13, 2008.

  1. jasondunn

    jasondunn Active Member

    I thought that the maximum resolution for a DVD was 720 x 480 (NTSC) or 720 x 576 (PAL). So what's this 852 x 480 resolution I see? Is that some sort of overscan resolution? I've always been curious about this...
  2. AtTheAsylum

    AtTheAsylum Well-Known Member

    You're right in that the maximum resolution of a DVD is 720x480 (NTSC) or 720x576 (PAL) but what you're not taking into account (I didn't understand it either until just recently ;) ) is that widescreen DVD's are generally anamorphically encoded. That is the picture is stored on the DVD in the resolutions above but is actually displayed in another resolution. Sounds confusing doesn't it?

    Here's a really, really good explanation (http://trac.handbrake.fr/wiki/AnamorphicGuide).

    Take a look at the section titled "What happens when anamorphic is turned off". This is basically the 720x404 resolution option you see in CD-M (ie: compress the vertical dimension to achieve the correct aspect ratio).

    The section titled "Crude anamorphic" is the 852x480 resolution option in CD-M (ie: expand the horizontal dimension to achieve the correct aspect ratio).

    If you don't want to loose any picture quality and space is not an issue choose the 852x480 option.
  3. jasondunn

    jasondunn Active Member

    Quite interesting - thanks for the explanation and link, I appreciate it!