Tuesday, 20 November 2012

Chapter 14: Digital Video Data Sizing

Digital Video Data Sizing

Data sizing is used for calculating the size of a video or movie. There a some calculation needed to be done before you can determine the size of a data. In order to calculate the size of a video, you must calculate the picture/frame rate of the video and the audio size.



Calculating the File Size of an Uncompressed Digital Video

The formula is as follows
  • Raw video data size = frame size (width X height) * frame rate (fps) * colour depth (in bytes) * time (in  seconds)
            
           8 bits                   = 1 byte
           1 kilo(bit/byte)     = 1,024 (bits/bytes)
           1 mega(bit/bytes) = 1,048,576 (bits/bytes)
           1 giga(bit/bytes)   = 1,073,741,824 (bits/bytes)


Calculating the File Size of an Uncompressed Audio File

The formula is as follows

         8-bit mono                      Seconds x kHz = Size
         16 - bit mono                  (Seconds x kHz) x 2 = Size
         8 - bit stereo                   (Seconds x kHz) x 2 = Size
         16 - bit stereo                 ([Seconds x kHz] x 2) x 2 = Size
         16 - bit 5.1                     ([Seconds x kHz] x 2) x 6 = Size


Eg. The file size for a 30 seconds of 16-bit, 11kHz mono audio is: (30 X 11) X 2 = 660KB


Factors to consider when selecting graphics to be used in a multimedia project

  1. Purpose
  2. Quality 
  3. Cost


No comments:

Post a Comment