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video bandwidth

When it comes to video bandwidth, you have to distinguish between the bandwidth for analog video and digital video. In general, the two are directly related and have been shaped by the development of television.

For a television picture, the transmittable bandwidth depends on the number of lines, the refresh rate and the aspect ratio. These three parameters determine the theoretical bandwidth value for the video signal. For PAL, this means: 625 lines, 25 frames and an aspect ratio of 4:3. This results in 625 x 833, i.e. 520,000 pixels and thus a bandwidth of 6.5 MHz. In PAL, this bandwidth, which is allotted to the luminance signal, is reduced at 5 MHz. From the resolution of the screen display of 520,000 pixels and a quantization of the color signal with 24 bits, a file size of 1.56 MB/ image or 39 MB/s results as an adequate bandwidth.

The CCIR has specified various file formats for the representation of digital video, which differ in resolution and thus in storage space requirements: the Common Intermediate Format( CIF) and QCIF as well as the ITU file formatBT.601 and HDTV.

Englisch: video bandwidth
Updated at: 24.08.2005
#Words: 176
Links: video, bandwidth (BW), analog, digital video (DV), indium (In)
Translations: DE

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