Broadcast Standards

Instructional Video Production 4(1+3)

Lesson 08: Video Formats

Broadcast Standards

Now that we have understood the meaning of analogue and digital technol­ogy, let us move on to understand the different broadcast standards in the world. Different parts of the world have different broadcast standards. By broadcast standards, we mean the protocol followed to broadcast and re­ceive television signals.

Television sets require a source of reference signals that tell the TV re­ceiver to be ready to receive the next picture in the stream of images. Early TV set designers decided to use the mains power supply frequency as this source for two reasons. The first was that with the older types of 'power supply, one would get rolling hum bars on the TV picture if the mains supply and the signal were not at exactly the same frequency. The second was that the TV studios would have had enormous problems with flicker on their cameras when making programmes. This resulted in a division of the world's TV systems into two camps-the 25 frames per second (50Hz) camp and the 30 frames per second (60Hz) camp. Later, for reasons both political (remember, the two World Wars!) and technical, countries began to develop their own broadcast standards.

National Television Systems Committee The National Television Systems Committee (NTSC) standard was Introduced in the US in 1940 as the first set of standard protocols for television. It is used throughout the US, Canada, and Japan and has been adopted in other countries as well. NTSC has 525 lines displayed at 30 frames per second. It has a lower resolution

Last modified: Monday, 23 April 2012, 6:44 AM