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  1. Member
    Join Date: Jul 2005
    Location: UK
    Search Comp PM
    Can someone tell me how I reduce the video size using avidemux?

    Yes!! I've read the manual

    1. Calculator: this doesn't seem to work for me!!

    2. Even if it did work, still no good for what I need it for
    I have several videos to encode for Flash video format
    For this, I want to be able to apply the same settings to all files and get videos out that have had the same compressions settings applied - this is different to simply deciding what end file size you want

    I've tried changing other settings, nothing works!

    APART from GOP size - what is this??
    I've tried googling this but having found anything meaningful

    Thanks


    OM
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  2. file size = bitrate * running time
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  3. Member
    Join Date: Jul 2005
    Location: UK
    Search Comp PM
    thanks for the reply
    it was set to bitrate of 1500
    so i set this to lower levels and went down to 300
    there seemed to be only negligible file size difference

    the *only* thing that made a difference was the GOP size
    confused

    let me know what you think

    thanks
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  4. GOP stands for Group Of Pictures. High compression codecs get most of their compression by only encoding the changes from frame to frame most of the time. They will start with one frame that is compressed like a JPEG image (an entire picture), called a keyframe, then for many frames after that only the changes are encoded. Eventually another keyframe is encoded followed by a bunch more change only frames. The distance from one keyframe to the next is the GOP size.

    GOP size does not effect the file size. At least not until you get into bitrates too low for the codec or very short GOPs.

    What compression codec are you using in AviDemux? Check your file to be sure audio isn't taking up a large part of the file size. Use GSpot or MediaInfo to determine the file properties.
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  5. Member
    Join Date: Dec 2008
    Location: Indonesia
    Search Comp PM
    # AVIDEMUX has internal file properties viewer .Just go to File-->Properties
    # AVIDEMUX seems don't have advanced flash video encoding setting
    # If you wanna be advance you can go to this thread :
    http://forum.videohelp.com/topic336882.html
    there you will find how to encode to flash video properly without being reencoded by the host

    Other alternative on reducing video size with AVIDEMUX but for AVI-XVID.
    It is truly reduce file size on output...........
    ( sorry if you already knew it )
    # if you are using XVID for output video codec,you can use "MPEG-4 ASP (Xvid4)"
    # click configure,use this setting on "main" tab :

    >>Encoding Type : single Pass (Quantizer)<<
    >>Bitrate-------------------------------- << (not set)
    >>Quantizer : 4.00 << (Quantizer number may vary due to input video properties)

    # you can concentrate on the "Quantizer" part and playing with the number there
    # the higher the number you set , the higher the compression you got, and so on
    # you can play with another setting next time
    # my experience proove that I can have output smaller at least half of the input, but still with acceptable quality.
    # Or if you would like extreme compression,use higher Quantizer number
    # As far as I know, playing with quantizer is better than force video output to certain size.
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