Virtualdub makes my mpegs BIGGER??

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  • singleshotbuff
    Junior Member
    Junior Member
    • Jul 2005
    • 4

    Virtualdub makes my mpegs BIGGER??

    Gentlemen,

    Please forgive a COMPLETE noob here, but I'm having a BIG problem compressing video with Virtualdub.

    I import the video from my camera as MPEG-1.

    I open the video in Virtualdub and try to convert it to an AVI and compress it. I have tried using several of the codecs that are shown in Virtualdub, I have tried to alter the framerate and I have even selected "no audio". No matter what I do, Virtualdub turns my 10mb MPEG-1 into an AVI of about 48mb!!

    I'm sure there is something simple that I'm missing here and I'm sure one of you experts can clue me in in about 30 seconds. I tried searching the forums first, but to no avail.

    Please help.

    Thanks

    SSB
  • LT. Columbo
    Demigod of Digital Video
    • Nov 2004
    • 10671

    #2
    what are your compression settings for the video?
    "One day men will look back and say I gave birth to the 20th Century". Jack The Ripper - 1888
    Columbo moments...
    "Double Shock" "The Greenhouse Jungle" "Swan Song" FORUM RULES
    "You try to contrive a perfect alibi, and it's your perfect alibi that's gonna hang ya."
    (An Exercise In Fatality, 1974)


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    • singleshotbuff
      Junior Member
      Junior Member
      • Jul 2005
      • 4

      #3
      Columbo,

      I'm not 100% sure, I know I changed the framerate down to 24(?) fps, and I think I turned the quality down from 100 to 75. What else should I adjust and how? Sorry if I sound dumb, I'm just trying to learn this.

      SSB

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      • tigerman8u
        Lord of Digital Video
        Lord of Digital Video
        • Aug 2003
        • 2122

        #4
        lowering the fps won't make the file smaller. video bitrate and audio k/bps will lower the file size. I use 124k/bps cbr 16 bit stereo for audio. for mpeg 1 resolution (352x240/288) you should be able to use 700-800k/bps and get good results.

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        • singleshotbuff
          Junior Member
          Junior Member
          • Jul 2005
          • 4

          #5
          Gentlemen,

          Thanks for the help, it got me started in the right direction. Here's what I have accomplished so far.

          I switched to DiVx 4.1 codec.

          I wound up (through trial and error) with 38-39 KBPS.

          These changes have allowed me to shrink a 10mb MPEG-1 down to 2.3MB with acceptable quality.

          Next I recaptured the video as a higher quality avi and wound up with a 181MB file that I was able to compress with these setting down to 1.8MB, still with acceptable quality.

          This has led to another issue/question, if I may.

          While the quality is still decent, the video is fast. Sort of like fast forward on the camcorder. The original 181MB clip is 1.01 min in duration while the compressed clip is only 0.49 min in duration. What have I done and how do I slow it down while retaining the quality I have achieved?

          Thanks in advance for any help.

          SSB

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          • tigerman8u
            Lord of Digital Video
            Lord of Digital Video
            • Aug 2003
            • 2122

            #6
            "the video is fast. Sort of like fast forward on the camcorder"

            sounds like you changed the fps on the video. load the original in virtualdub and click file>file information and check the length and fps of the video. do the same for compressed file. If you speed up the fps you can get the fast forward effect because the video is running faster. the fps can be changed but it has to be done properly.

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