INTERACTIVE TELEVISION

I N T E R A C T I V E      T E L E V I S I O N

THE FUTURE OF TELEVISION is undoubtedly digital. Television or video signals can be converted from their normal analogue form (continuously varying) into digital form, Which consists of a series of definite pulses rather like Morse code. Digital signals  can be transmitted' compressed , and manipulated by computers without any unwanted "noise"affecting the data. One of the advantage of digital technology is that video data can be manipulated to make interactive television possible. Interactive "video-on-demand" (VOD) services allow users to watch the material of their choice from a large central video vault. A digital server enables many users to watch the same film, starting  at different times, by sending the video data in small "packets" to them. Other services include news programmers, games, music, and electronic shopping. With the latter, the user "strolls" through a virtual shop and uses a  credit card to buy items, Which are then delivered to the within days.

NEIGHBOURHOOD  NODE:                                                            MODULATOR :

The junction box , or neighbourhood node,                                The information  received by the  

 converts the fibre-optic cable's  optical                                      modulator is converted to the correct

signals into an electrical signal, which is                                     frequency for its journey to the home.

transmitted via coaxial cable to different

 homes in the neighbourhood.

STORAGE VAULTS

Digital video data is compressed before being stored in vaults. A typical vault may house up to 100 magnetic hard drives.

VIDEO-ON-DEMAND

Allowing viewers to choose a film or television programme  from a vast selection whenever desired, video-on-demand comes complete with all the flexibility of a  video recorder (including fast- forward, rewind and pause facilities). A typical VOD system consists of video vaults containing compressed digital video data, a sophisticated digital server that sends the requested material to the correct destination, and decoder and remote control units in the home.

DIGITAL VIDEO DISC

The video format set replace tapes and laser discs in the home looks exactly like an audio compact disc (CD)- a silver platter 12 cm(4 3/4 in) in diameter. (To avoid a repetition of the 1980s VHS/Beta video-cassette war, electronic companies involved have agreed on one format.) However, the digital video disc can hold up to 9 hours of data on its 2 sides, with each side containing 133 minutes of programme time. This is compared with the 74 minutes held by a CD. In addition, DVD's interactivity means that certain programmes can be viewed from a variety of camera angles. 

CINEMA BY COMPUTER 

Disney productions TOY STORY (1995) was the world's first feature film to be generated entirely on computer. A team of 27 animators worked on the film, producing an average of 3 1/2 minutes of footage per week. Some of the  characters and scenes were created solely on computer, whereas others were set up with models and props before being scanned in the computer  for digitization.