Tuesday 30 June 2015

Evolution of Video Streaming (I)

       Sixty years ago, families in USA used to watch television programs in 14” CRT (Cathode Ray Tube) screens. Today, an Indian teenager waiting for a bus in a bus stop uses his 5” smartphone and access video through Internet. Digitized colour video signals are streamed to an individual. Earlier analogue B&W (Black and White) Television (TV) signals were broadcasted to all the viewers. In the span of six decades lot of changes have occurred. The video resolution has increased; use of digitized video signals (colour) became the norm; wide use of LED and LCD screens; wide range of screens (4” to 80”).  In the video distribution front, Internet is competing with traditional TV broadcasting stations. The way viewers consume the video content has changed too. The shift is from ‘fixed-time and family-centred’ to ‘any-time and individual-centred.’ Half a century ago if any one prophesied that “One day people will have telephone at their hands and using that telephone they will watch TV,”  he/she would be branded as lunatic. Today we use smart-phone to talk, run few apps (applications) as well as to watch videos from YouTube.

Earlier TV sets were connected to roof top Yagi-Uda antenna using flat ribbon cable. Unlike FM antenna (i.e. dipole antenna) Yagi-Uda antenna is a directional antenna. So, it has to be positioned towards the direction of TV signal broadcasting station. Channel changing has to be carried out by changing the position of the knob in the TV. Wired or wireless remote control was not available. Receiving two TV channels is a luxury.