video file size issues!

Discussion in 'Digital Video' started by ern17, Feb 11, 2010.

  1. ern17 macrumors newbie

    Feb 11, 2010
    Hi. I don't understand why every time I create a movie file with iMovie (HD 6.0.3) the video files get so huge when I try to export them? This happens with videos from either my camera or my phone.

    One example: A 22 minute video that I bring in from my phone in 3gp format and is only 29.5 MB, once I bring it to iMovie and edit it down to only 4 minutes, the only way that I can export it w/o seeing a huge reduction in quality, was in dv format and a whooping 835.5 MB.

    Why? How? It's sooo much shorter, and yet sooo much bigger?

    I know I'm missing something really dumb, so please be gentle.
  2. spinnerlys Guest


    Sep 7, 2008
    forlod bygningen
    .3gp files use an MPEG-4 codec, which is not suited for editing, thus iMovie needs to convert the video to something it can edit with. The DV codec is quite good for that, but the "down-side" is the bigger file size, the DV codec needs 220MB/min to store the video data.

    When you export as a .dv file or a QuickTime (.mov) from iMovie, you can then use MPEG Streamclip to convert that exported file into a .mov using the H264 codec, which is also a variant of the MPEG-4 codec. That will save you some HDD space.

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