Pixel by pixel

Discussion in 'Computer Science & Culture' started by curioucity, Oct 29, 2004.

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  1. curioucity Unbelievable and odd Registered Senior Member

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    Hello everyone

    I'm merely curious on how different picture files store the image in the bits, that is, how the bit values are stored. Like for example, I think that in 24-bit BMP, the file stores these information:
    -some bytes for filename
    -some bytes for size
    -3 bytes per pixel, stored in width-sized strings (e.g, in 800x600, the pic is stored in 801x3 bytes per string style, with the extra byte as end-line mark)

    please help me satisfy my curiosity, thank you

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    (file types in my question are importantly: bmp, jpeg/jpg, gif and later avi and other movie files, tiff)
     
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  3. Voodoo Child Registered Senior Member

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  5. curioucity Unbelievable and odd Registered Senior Member

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    Umm, okay, thanks.
    By the way, a bit related (though a bit far), I just found out that the file extentions .avi and .mpeg (or .mpg) are interchangable. Any explanation?
     
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  7. sargentlard Save the whales motherfucker Valued Senior Member

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    You mean movie files?..then yes, they can be converted to each other.

    For .mpeg > .avi get virtualdub (wonderful little free tool)

    and for .avi > .mpeg get tmpegnec
     
  8. Voodoo Child Registered Senior Member

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    Probably the program using these files doesn't rely on the suffix to determine what codec to use.
     
  9. §outh§tar is feeling caustic Registered Senior Member

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    GSPOT determines codecs
     
  10. curioucity Unbelievable and odd Registered Senior Member

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    Hmm, I think I'll tell you some back story about this...

    Long ago, I dl-ed video clips via p2p sharings (the clips are in either mpeg or avi format), and burned them to CDs. Recently when I checked, in one of the CDs, all of those clips suddenly lose their extentions (even though I was sure there were when I burned em), though they are still playable with WMP. Because of that, I add the file extentions myself, but at one time after I put .avi (and play it with WMP without problem), I decide to undo the name change and put .mpeg to the file and it's still playable O.O

    So, who's right?
    Thanks anyway for the replies.
     
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