Delayed broadcasting system is one of the important parts for digital TV.

Introduce how to realize live and delay broadcasting,satellite download program to broadcasting in hardware using video service in Tangshan TV station.

The paper introduces the main technology of Hard Disk Auto Play System,analyses the key technology of Hard Disk in that Sys- tem.

Hard disk broadcasting system is an automatic programming and broadcasting system with video server as the central unit, and works through initially digitizing and compressing image and voice signals into hard drive and broadcasts according to program needs.

The broadcasting system of the radio station plays an important role in exchanging, processing, transmitting, controlling and broadcasting of the programmes.

Broadcasting system is transiting from traditional and manual to digital and automatic hard drive broadcasting way, which integrates multi-media, database and network tech.

It s concluded that facilities cascade model can be switched into parallel model by using a keying amplifier in broadcast system to improve broadcast quality.

The reliability of digital television broadcast system can directly reflect the quality of the system and is very critical for the proper function of the system.

The design principles of broadcast system for middle and small scale TV station are presented.

Prediction and compensation algorithm for time-delay system based on dynamic matrix control;