Research In The Entropy Coding And Network Transporting Of H.264 Video Coding Standard

H.264 is the new video coding standard, which is developed jointly by ITU-T and ISO. H.264 has a good perspective in the digital video communication and storage applications because of its high compression ratio, advanced multi-layer structure and good network adaptability. Due to the above background, this thesis does research on the theory of the entropy coding of the H.264, and has implemented three core modules of its entropy encoder using FPGA. Meanwhile, depending on the analysis of its network adaptability, this paper presents a design of network interface for H.264 encoder using AVR MCU and RTL8019AS NIC.Compared with H.263, H.264 can averagely save 50% data rate with the comparative quality of the rebuilt image. The enhancement of compression ratio in H.264 is much related with its more advanced encoding technologies, including new entropy coding technology.There are three kinds of entropy coding technology in H.264: Exp-Golomb,CAVLC and CABAC. This paper mainly does research on the Exp-Golomb and CAVLC used in the Baseline profile of H.264, and combining with the EDA technique, implements its three core modules by Verilog HDL using the CycloneⅡFPGA chip of Altera company. These modules are Exp-Golomb coding module, 4×4 coefficient block level coding module and variable length code patching module. These modules are all logically synthesized by QuartusⅡ, and finally emulated by the ModelSim.H.264 first introduced the multi-layer coding technique, which puts all the issues related with the transmission into the Network Abstraction Layer. Therefore, it has much better network adaptability. Based on this background, this paper presents a low-cost design scheme of network interface for the encoder using the ATmega128 and RTL8019AS. Combining withμC/OS-ⅡandμIP, this paper creates a multi-task framework to develop network software on the above hardware platform, describes the porting ofμC/OS-ⅡandμIP in detail, tests the entire system with the testing program developed by VC++6.0, and analyses its TCP and UDP transmission speed limitation by network analysing software. The result of the test indicates that the above design meets the need of bandwidth required by low data rate H.264 video stream.