Change aspect ratio of avi?

Discussion in 'Mac Apps and Mac App Store' started by ggulliver, Mar 2, 2011.

  1. ggulliver macrumors member

    Joined:
    Jan 22, 2008
    #1
    I sometimes get avi files with incorrect aspect ratios - usually squashed horizontally.

    I know I can play them ok by changing VLC settings or shift-dragging the viewpane in QT - but is there an app which'll permanently set the correct aspect ratio without re-encoding?
     
  2. simsaladimbamba

    Joined:
    Nov 28, 2010
    Location:
    located
    #2
    Not that I know of. But using VLC Player and the "A" key should suffice, shouldn't it?
    Btw, what aspect ratios are you talking about, the pixel aspect ratio or the image aspect ratio or both? In what way do they differ? Is 4:3 footage squeezed to 16:9 or vice versa?
     
  3. ggulliver thread starter macrumors member

    Joined:
    Jan 22, 2008
    #3
    Thanks.

    Much (almost all!) of this is beyond my current knowledge - and it's something on which I don't want to be spending a lot of time/effort, just enough to be able to do what's required and understand a little better. So excuse me for being less specific on the aspect ratio issue.

    One example has a display aspect ratio of 1.6 - resulting in the squashed-horizontally appearance. When viewing in VLC, changing the aspect ratio to 16:9 appears to normalize things, and in the absence of a better alternative I'd then edit in avidemux to an appropriate size/ratio and then resave - but that's time-consuming.

    I'm aware of PC apps (MPEG4 Modifier) which'll reset either/both the pixel/display aspect ratio of avi files without re-encoding, hence my hope for something similar on Mac.

    I don't often use VLC, so what's the A-key thing? And surely VLC is read only and hence changes can't be saved?
     
  4. simsaladimbamba

    Joined:
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    #4
    VLC Player can be controlled by a variety of keyboard shortcuts, "A", the key, being one of them. Pressing "A" on your keyboard lets you cycle through the different aspect ratios, but you can't save the selected aspect ratio into the file or a new file.

    If your intended use of the files is editing, I would advise using MPEG Streamclip to transcode the video (convert) to a QuickTime (.mov) using the Apple Intermediate Codec for video and Uncompressed for sound and choosing the right frame size or making a custom one.

    Or have you tried this? http://forums.macrumors.com/showthread.php?t=176944
    You need QT Player 7 for this, QT X will not do that.
     
  5. ggulliver thread starter macrumors member

    Joined:
    Jan 22, 2008
    #5
    Thanks.

    For speed and ease I prefer to keep it as an avi - so those options aren't suitable.
     
  6. sammich macrumors 601

    sammich

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    Sarcasmville.
    #6
    Completely off topic buuut:

    Every time I see this thread title I read: Change aspect ratio of evil
     
  7. simsaladimbamba

    Joined:
    Nov 28, 2010
    Location:
    located
    #7
    I just opened a Divx encoded .avi file in QT Player 7, did change some values and chose SAVE AS and SELF CONTAINED MOVIE and the resulting .mov file was 6MB bigger and was created in less than a minute on my 2007 Mac with 2GHz.
    But I guess avidemux does not handle .mov files?

    Anyway, what is it you want to do with the .avi files? You can edit in QT Player 7 and you can also cut parts (trim) in MPEG Streamclip.
     
  8. ggulliver thread starter macrumors member

    Joined:
    Jan 22, 2008
    #8
    They're for use in a stand-alone dvd player - hence the requirment to keep the avi container rather than mov.
     
  9. BrianBaughn macrumors 601

    BrianBaughn

    Joined:
    Feb 13, 2011
    Location:
    Baltimore, Maryland
    #9
    Try using MPEG Streamclip to convert to a new AVI.
     
  10. ggulliver thread starter macrumors member

    Joined:
    Jan 22, 2008
    #10
    Then I'll be re-encoding - something I'm trying to avoid.
     
  11. ggulliver thread starter macrumors member

    Joined:
    Jan 22, 2008
    #11
    Thanks.
     

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