Video Rate Calculation II

Discussion in 'MPEG-1 and MPEG-2 encoding (AVI to DVD)' started by gkrshnn, Nov 13, 2003.

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  1. gkrshnn

    gkrshnn Member

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    I have found the following formula:

    (Size - (Audio x Length )) / Length = Video bitrate

    Here the Size (of the disc) is in KB.

    So, 4.36GB,

    is it equal to 4.36*1,000,000 KB

    or, is it equal to

    4.36*1,000*1,028 KB?

    Or, is the 4.36GB equal to something else?

    By the way, where did the 4.36GB come from?

    Thanks.
     
    gkrshnn, Nov 13, 2003
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  2. vurbal

    vurbal Administrator Staff Member

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    Companies that sell blank DVDs advertise/label them as being 4.7GB, which translates to 4.7 Billion Bytes. This isn't technically accurate, because your computer sees 4.7 Billion Bytes as 4.3772161006927490234375GB, therefore the amount of data you can burn to the disc is about 4.37GB. Many people use the number 4.36GB to allow a larger margin for error.

    Basically, the manufacturer's number treats Bytes as a metric unit, meaning that 1GB=1000*1000*1000 Bytes, but since computers use Base2 numbers instead of Base10, Byte isn't a metric unit and the correct calculation is 1GB=1024*1024*1024 Bytes. That's not really important to understand as long as you remember that 1KB=1024B, 1MB=1024KB, 1GB=1024MB, 1TB=1024GB, etc,...
     
    vurbal, Nov 14, 2003
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  3. Praetor

    Praetor Moderator Staff Member

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    Praetor, Nov 14, 2003
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