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MPEG2 or AVI

Discussion in 'Video capturing from analog sources' started by rattar, Sep 4, 2004.

  1. rattar

    rattar Member

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    I would like to transfer all my analog video camera tapes to a digital format
    I did few tests and found out:
    1. a 1 hour AVI file at 320 X 240 is 14GB
    2. a 1 hour MPEG2 file at 720 X 576 is 4GB

    Does it sound reasonable?
    Which format to use?
    Does it make any different in quality assuming the source is an Analog HI8 video camera?

    Thanks in advance for any input...
     
  2. turkey

    turkey Regular member

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    the results from both of your tests look resonable, but it also seems obvious which format you should be using... you are capturing Mpeg2 at a higher resolution and with smaller file sizes, and indeed Mpeg2 is the univerally prefered format for storing digital video.

    the drawback to mpeg2 is that it is not a lossless video conversion like AVI can be. AVI can achieve video quality that is a closer representation of the original source then can mpeg2. however, in your case you would need to increase the resolution of the AVI capture to achieve this quality which would considerably increase the file size as well.

    so AVI is better in terms of overall quality but mpeg2 is superior to any other format in terms of the ratio between quality and file size.
     
  3. Minion

    Minion Senior member

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    If you want to Capture to AVI but at 720+480 and you don"t want the Files sizes to Be as Huge as they are useing Uncompressed AVI the Try useing the "HuffYUV" codec...It is Totally Lossless and will Suck up about 30gb per Hour of Video at 720+480...

    If you want even Smaller File sizes then check out the "PicVideo Mjpeg Codec" it isn"t Lossless but when captureing at 20 Quality it is Fairly close to lossless and will use less than Half the Disk Space of HuffYUV and a Quarter the space of Uncompressed AVI....

    Cheers
     
  4. rattar

    rattar Member

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    Many thanks for your response
    I also would like to address the following issue:
    If I will capture a 1 hour of video to MPEG2 720 X 560 I will get ~4GB
    If I will need in the future to burn it into single DVD, it will feet perfectly with no further compression. If I will need burn into a single DVD a large 25 GB AVI file I will need to compress it anyway, so the end of the day it is an issue whether the quality of the compression is better if you go directly from analog media to MPEG2 or capture to AVI and then compress to a DVD media.

    Thanks again for all your help
     
  5. turkey

    turkey Regular member

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    i think you are on the right track with your logic. just keep in mind that the best way to compress a 25GB AVI to fit on a DVD is to convert it to mpeg2. so one way or another, if you are dealing with DVD's then you will be dealing with mpeg2.

    indeed it will save you time to capture your footage directly to mpeg2 but there is a definate quality advantage to capturing to lossless AVI ("huffyuv") and then compressing/encoding the AVI to mpeg2 later.

    it's your call, save time - or - save quality...
     
  6. Doc409

    Doc409 Active member

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    When you speak of avi or mpeg, is there always a choice of which can be used? The case in point, I wanted to get the Canopus ADVC100 because of the locked A/V. It is advertised as converting analog to digital video, yet I can't find which digital format (avi or mpeg-2)? I'm new to this end of things, and I'm wondering if it is just understood that DV/digital video means both formats?


     
  7. turkey

    turkey Regular member

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    under normal capturing circumstances a simple decoder chip allows a source signal to pass into the computer and the analog to digital conversion happens on your computer's CPU. so when capturing to the computer the software allows you a choice of which format to convert to; like AVI, mpeg2 and others. but with the ADVC-100, and the other canopus products, all the processing is done on the device itself, such that the ADVC only captures in one format; namely "DV AVI".

    DV AVI is the format used by DV cameras and other devices that convert analog signals to a digital format specifically designed to be transfered over Firewire (IEEE 1394). DV AVI is superior to regular AVI in both quality and compression which also happens to make the eventual conversion to DVD compliant mpeg2 very efficient. and so, to answer your last question; when someone says the video format is "DV", that is just short-hand for "DV AVI"...
     
  8. Doc409

    Doc409 Active member

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    turkey ... this was a very nice explanation. Thanks for clearing the fog. Could you give me some kind of idea of what the HDD file size of a 1 hour DV AVI file might be? Along these lines I'm also wondering if three 20 minute VHS-C tapes converted to DV AVI will be about the same GB as one hour of DV AVI from a camcorder?
     
  9. Minion

    Minion Senior member

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    The DV AVI format uses about 15gb per hour of video so it uses quite a Bit of Space but the Files should be very good quality...And yes 3 20Minute Tapes converted to DV AVI would take up the same ammount of Space as an hour of DV from a Camcorder....

    Cheers
     

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