100mb video=1gb or more in iMovie and iDVD!??

Discussion in 'Mac Apps and Mac App Store' started by AlmightyG5, Jul 20, 2005.

  1. AlmightyG5 macrumors 6502

    Joined:
    Jul 7, 2005
    #1
    I have 10, 100mb video files that i converted from .avi to .mov with ffmpegX. The files size stayed the same give or take a couple megabytes after the conversion. I put these ten files into iMovie witch should equal around 1gb. 100mb x 10=1000mb. But after i saved the iMovie and looked at it's file size it said the poject was 22gb!!! Also when i put one of the files in iDVD which should be around 100mb out of 4gb of space...the one video file took up a gb of space.

    Does anyone know whats going on here?
     
  2. zim macrumors 65816

    zim

    Joined:
    Jan 5, 2002
    #2
    Most likely what you are seeing is that iMovie has converted the files to DV format. DV has a much larger file size.

    That is my best answer... too hot to think.
     
  3. yellow Moderator emeritus

    yellow

    Joined:
    Oct 21, 2003
    Location:
    Portland, OR
    #3
    Yes. Digital video, such as you have in iMovie and iDVD, are barely compressed. Therefore, what you have in a very compressed .avi and a very compressed .mov are suddenly huge in size as all compression is lost (sadly without gain in quality).

    Unfortunately, I cannot find the ratio of video time to approximate size on the disk at the moment.

    EDIT: Found it (thanks Wintermute!)

    http://forums.macrumors.com/showpost.php?p=1529056

     
  4. AlmightyG5 thread starter macrumors 6502

    Joined:
    Jul 7, 2005
    #4
    so is there a way to make the video import to mpeg2 or some other compression so the files are 100mb like they should be?
     
  5. AlmightyG5 thread starter macrumors 6502

    Joined:
    Jul 7, 2005
  6. yellow Moderator emeritus

    yellow

    Joined:
    Oct 21, 2003
    Location:
    Portland, OR
    #6
    As far as I know, no. A DVD's video is DV, and therefore, uncompressed. But I'm not a video engineer, so you should wait for one of those.
     
  7. stoid macrumors 601

    stoid

    Joined:
    Feb 17, 2002
    Location:
    So long, and thanks for all the fish!
    #7
    DVDs are encoded in MPEG2. Otherwise to fit a 2 hour movie the disc would have to hold about 25GB. As far as I know, there is no way to get iDVD or iMovie to use MPEG2 instead of DV streams.
     
  8. bootedbear macrumors 6502

    bootedbear

    Joined:
    Sep 13, 2004
    Location:
    Austin, TX
    #8
    iDVD will take the input DV and convert it to MPEG-2 using one of two schemes (called 'best performance", a single pass encoding, or "best quality", dual-pass encoding). So the size of the input files are really rather moot. What really matters is run-length.
     

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