Optimizing and Realising Research on Vedio Compression in TV Guidance System
|School||Harbin Institute of Technology|
|Course||Information and Communication Engineering|
|Keywords||Video Compression H.264 DSP FPGA Motion Estimation Algorithm|
TV weapon guidance is one of the widely used accurate weapon guidance methods nowadays, the key technology of which is the video signal transmission. The conventional analog signal is gradually replaced by the digital signal because its needing broader bandwidth and subjective to noise. In order to transmit as many data as possible through the limited channel and to get high quality and real-time video images, it is necessary to compress the digital video. In this application background, the dissertation researches and implements the video sub-system of the TV weapon guidance system based on the video coding standard H.264.While being a new gerneration video coding standard, H.264 is more suitable for the application to TV guidance for its high efficienct coding with low dealy. In this dissertation, the key techniques of H.264 video compression are studied to implement an image processing machine for TV guidance.Firstly, the fundamentals of H.264 video coding are thoroughly researched, and the coding characteristics are systematically analysed in this dissertation. After the techniqual framework of many image and video coding standards is summarized, the comparison of them is also conducted, and the principle of high compression efficiency of H.264 is analysed. This process helps us to understand the unique dominance of H.264. Furthermore, from application point of view, the coding characteristics are systematically analysed, the coding efficiency is compared and analysed variously. These studies provide necessary theory basis for the application.Secondly,The software simulation aims at the key module of the motion video compression algorithm H.264-Motion Compensation and introduces its theories and important elements. We estimated the advantages and disadvantages of the existing classical model based on block matching search fast algorithm.With the above result,we put forward a improved fast searching algorithm based on the motion vector probability distribution. In the trial,we used a variety of different types of video sequences to test algorithm’s performance in different Entropy coding method. Thirdly,with the actual system’s requirement on the processing time and power, a H.264 coding scheme is designed for TV guidance, and research is conducted on two aspects. The main research of the paper is to design a real-time video compression platform based on DSP. In the transmitter, analog video signal is acquired from the input digital port, compresses the video sequence using H.264 algorithm, the compressed data flows through the Channel Tunnel, in the receiver the code is decompressed, video shows back to the monitor at last. On the basis of the normal operation of the system, the paper also does an optimization on system-level and function-level respectively, finally it results a good image restoration. The system has a stable and flexible, maintenance-friendly features.Lastly,we design to use FPGA to realize a kind of intra-prediction algorithm, which decide the intra-prediction mode by the grads.In order to enhance the speed of the design, we use pipeline architecture and ping-pong operation in the I/O port. With FPGA’s advantages of abundant logical element,high speed parallel computing,abundant I/O ports, our design is clear in architecture,and of much better performance than DSP in speed. This design is well meet the real time requirment.