Research On The Key Technologies Of Digital Television System

As the State's economy and technology are moving forward, along with an enhancement of the level of the public consumption, the technologies about Digital Television have also evolved from theories to practical applications. The State Administration of Radio Film and Television (SARFT) has released the "A transitional timetable of CATV from analog to digital" which proposed to accomplish the television digitization and stop the transmittance of analog signals nationwide in 2015. Some shortcomings do exist in the current digital TV system, the shortcomings hinder its development. This article presents new solutions to these shortcomings, which include:1. A Fine Granularity Scalability Video Coding Algorithm Based on the Two-stage Motion Compensation. The two-stage motion compensation scheme divides the non-zero quantized DCT coefficients of motion residual into two groups according to the corresponding quantized DCT coefficients of the current coding blocks , and implement the motion compensation by two steps with them. Promising simulation results are produced that the coding efficiency is improved over 2 dB by the new FGS coding algorithm.2. Algorithm Optimization of the MPEG Encoding. MPEG algorithm is an asymmetric algorithm, in which the computation of encoding is heavy while that of decoding is light. In the encoding algorithm, the DCT transform and Motion estimation are the biggest computation consumers. At the same time, the huge volume of video data makes it indispensable to impose constraints on the encoding data stream. This paper has presents optimizations of data stream, DCT transform and Motion estimation.3. Flash Memory File System for the Digital TV STB. This file system uses flash as the storage media to save different kinds of changing data of the STB. It has employed technologies such as wear leveling, garbage collection, power failure protection and etc and consequently hastened the storage speed, prolonged flash's life expectancy and enhanced STB's stability.The new solutions presented in this article have been applied in practice,and created 1.2 billion RMB income.