VirtualDub

Discussion in 'Other video questions' started by HelpPleas, Aug 24, 2006.

  1. HelpPleas

    HelpPleas Regular member

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    Hi,
    I used VirtualDub with TechSmith codec to "compress" an AVI file that I had imported to my Hard drive from Digital video camera. The original AVI file was 3Gigs. The "compressed" file was 16 gigs.

    Anyone know why??

    I have since used a different codec with VirtualDub and got the AVI compressed OK.

    But I would like to know does anyone know why the file turned out bigger and is there a way I can use the TechSmith codec to compress rather than make the file bigger.


    Also.....I would like to know (answer may sound obvious from above),
    Is it possible to uncompress an AVI that has just been compressed and have it back to its exact original size (or close enough to it).

    Hope all this makes sense.
     
  2. celtic_d

    celtic_d Regular member

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    The TechSmith codec would have been designed for screen capture. Used for this purpose it should compress well, used on real video it won't be anywhere near as efficient.

    As for compressing and decompressing. Only time that would really be possible would be where you have a raw source and compress with a lossless codec. In such a case you could decompress back to raw with 0% quality loss. Sounds like you have DV, which is lossy, so compressing with a lossless codec would most likely result in an increase in filesize. Also since DV is lossy, once you recompress as DV, although you would get the original filesize, you would lose quality.
     
  3. HelpPleas

    HelpPleas Regular member

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    thanks Celtic.......been trying to find out all that for ages.....
     

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