1前言迄今报道，国内有线电视台有近3000家，8000万用户，收费难一直困扰各台，巨大的市场刺激着各大制造商。早期的基于视频处理的各种加解扰寻址系统因价格太高，不适合国情，难以推广应用，制造商亏尽血本的事实早已众所周知，大卫公司乃其中之一。虽然吃了苦头，大卫公司仍 1 Preface So far it has been reported that there are nearly 3,000 domestic cable television stations and 80 million subscribers. It is hard to keep up the toll collection rates and the huge market has stimulated major manufacturers. Early various video-processing-based descrambling and addressing systems are too expensive, not suitable for the national conditions, it is difficult to promote the application, the fact that manufacturers have to make a full loss of the blood has long been known, David is one of them. Although eaten a lot, David’s still