Digital television: making it work

Abstract

Now that the US standard for digital TV has set technical parameters, equipment has to be built for production, editing and broadcast. The full-production HDTV facility must support existing NTSC equipment. When possible, it also must allow compressed operations (like storage and splicing) to avoid encoding and decoding penalties. The configuration resembles that being created as part of the NIST HDBT project. In this setup, a high-speed ATM computer network routes the compressed bit-stream around the studio. Besides the compressed video, the ATM net routes intercom, digital audio (compressed or not), and data. All the equipment (servers, encoders, and the off-line transcoder) interfaces to the ATM router, which is the studio's central switch, replacing the router of conventional studios. The transcoder's job is to convert one compressed format into another. All the devices on the computer network are controlled by the studio control workstation. This architecture also allows connection to be made to other TV studios over existing telecommunications networks. A network interface device has this job. In the early stages, video production will be performed on uncompressed video. As compressed technology advances, more production will be done on compressed video. Most studios will probably transition to compressed production but retain uncompressed elements to take advantage of some of its features.