AFD Based HD/SD Production And Broadcast System

With the development of high-definition television, TV stations will vigorously build HD/SD simulcast channels. Due to the diversity of aspect ratio of HDTV and SDTV, the complexity of broadcasting network, and problems to be solved that distortion and and redundant black bar occurring in the final aired images, this paper utilizes AFD(Active Format Description) to identify different types of programs source to realize the auto-adaptive control and management of aspect ratio, and effectively solve the problem of distortion and redundant black bar, and improve the final aired images.Firstly,this paper has a in-depth analysis of HD digital video signal, and consult the SMPTE standard file, which gives the embedding method of AFD code in the program. Secondly, according to the working process of the broadcasting system in TV station, we developed a set of reasonable aspect ratio conversion strategy for different types of program source using different AFD code so as to achieve the ideal effect of the final aired image. In this paper, we also give the evaluation method of final aired image. Both the default mode and the AFD mode are evaluated, and we proves that the AFD mode is the best solution.