Design And Implementation Of The Television Delay

TV station is one of the most important fields in the media and public opinion. By improving the indicators of the quality of broadcasting signal, the content of broadcasting and the broadcasting time, TV can play the right role of public opinion. With the improvement of the broadcasting quality and the diversity of broadcasting forms, the form of live broadcasting is being widely used. In the course of the live broadcasting, although the security and stability of the broadcasting equipment in the engine room have been improved greatly, some things that we can't forecast may happen. Delay broadcasting is an effective way to avoid some bad things broadcast. By this way, instructors in broadcasting have enough time to deal with the emergency and without affecting the timeliness of broadcasting.Based on the current situation, a delayer is design in this article. It achieves three major functions. First, it is delayed broadcast, which is the basic requirement of delayer. The delay time can be setting according to the demands. Second, it can realize immediate broadcast. When the live programming is directly broadcasted, this function is enabled. The last, it is the replacing broadcasting. When an emergency condition happens, it can be replaced by the program that we have prepared and the continuity of TV program can be maintained.When the delayer is designed and realized, the delay function is achieved firstly. With the help of the SDK of SD100, according to the functional requirements of the delayer, we designed some functions to make the TV program be recorded and then be broadcasted. The data of audio and video is stored in the memory. When the capacity of data reach the demands of the delay time, the thread of broadcasting starts up. The delay broadcasting program is archived. In the mode of immediate broadcasting, the threads of recording and broadcasting that are achieved in the mode of delay broadcasting are reused. The data of recording is broadcasted immediately and is not stored in the memory. The last is the mode of replacing broadcasting. A new thread is designed and it can broadcast the program which was stored in hard disk.Finally, the function of delay broadcasting, immediate broadcasting and replacing broadcasting is realized in the design, and these three functions also can be switched as required. The testing result shows that it meets the design purpose.Using delayer, the unhealthy broadcast program can be avoided, the quality of broadcasting can be improved, and the security of broadcasting is greatly enhanced.