The Development And Research For HD STB Software Based On EM8623L Platform

At present,most of the high definition digital TV set-top boxes(HDTV STB) use high degree of integration of single-chip solution.The maximum parameter support 1920×1080i/1920×1080p digital image decoding.Compared to the standard definition TV set-top boxes(SDTV STB) which support 640×480 image decoding, high definition digital TV set-top box will not only support the play of high definition signals,and also can compatible with the play of standard signal.Because of the good support for high definition documents,In addition,its original features,HDTV STB gradually toward the support of high quality audio and video output With the development of high definition digital TV set-top boxes that have the ability of high definition decoding in embedded field.A variety of multimedia solutions are being introduced which based on 32 bit RISC chip.In this paper,we use the high definition television(HDTV) decoding solution of Sigma Design.To develop high definition digital set-top box based on EM8623L.In this paper,the research focused on several key modules of HD STB software layer.(1) This article discusses the design and implementation of real time clock chip control pcf8563 drive module that PVR needs.We use two gpio pins to analog i~2c (Inter-Integrated Circuit) bus operation and address the i~2c bus pin problem of inadequate of EM8623L.(2)We put forward a new type of private reliable udp (PRUDP) in the long distance large amount of data download module.We can use a new type of download algorithm based on PRUDP to download data from the point to point server.The download rate of effective data can up to the existing bandwidth of more than 80%,this function is a very good solution to the current shortage of high definition movie source,with the expansion of good features,such as fixed or regular play.This article gives the detail instruction of the structure of the download algorithm.(3)This paper optimizes the Matroska module,and put forward a new type of key frame search algorithm.Successfully realized the time sync a period of time for fast forward while play high rate which may greater than lmbps.The percentage jump finished in a short time with the direct position shift.At last,we test the above mentioned research results,and give the test data to confirm this thesis research.In this paper,the difficult works focus on the design of a new type of PRUDP,the research and analysis based on PRUDP download algorithm,we adopte different packet retransmission mechanism or packet supplementation mechanism according to the packet loss rate of different network.The method based on PRUDP shows a more robust capability to receive data in the network environment of higher rate of network packet loss.During the process of optimize Matroska module,the analysis of Matroska format and key frame search algorithm are also the difficult point of this article.