Image Compression CODEC And Network Transmission Based On Davinci

The H.264 video compression standard is a new generation of video compression coding standard introduced by ITU-T/ISO in 2003. Compared with former standards of this kind such as H.263 or MPEG-4, the rate of error can be reduced by about 50 percent when using H.264 meanwhile maintaining the same quality. H.264 can be divided into three Profile: baseline, main and extended, each one aimed at a different application occasion. Now H.264 has begun to receive extensive application in many fields.In order to realize the H.264 CODEC standard, the CODEC algorithm is generally achieved by using embedded platform such as specialized H.264 CODEC chips or DSP-based algorithm. In this dissertation we use the DM6446 processor chip which is newly presented by TI. With an internal double-core integrated ARM and DSP, this chip is the more appropriate choice in realizing H.264 algorithm given its characteristics of high performance, low power cost, a specialized video and image processor as well as a video processing subsystem, large memory capacity and numerous peripheral equipment.This dissertation is engaged in the H.264 CODEC algorithm, including the analysis of intra prediction, the inter-frame prediction, CAVLC, CABAC, NAL layer and RTP/RTCP protocol, etc. In the progress of dissecting the codes of JM10.2, especially we conduct analysis on concrete examples targeted on Exp-Golomb CODEC and CAVLC (Context-based Adaptive Variable Length Coding). After thoroughly analyzing the codes of NAL (Network Abstraction Layer) and RTP protocol, we also represent the software structure of Davinci.Based on all the above research, in order to build the hardware system, this dissertation designed the theoretical graph of the DM6446-based system through Capture software developed by Cadence Company and designed PCB by using Allegro software also developed by Cadence. Furthermore, we also designed the hardware system with DM6446 its core. In software, we completed the intact H.264 CODEC and network transmission program with VC6.0. Experiments showed that H.264 algorithm had tremendous advantages in raising compression rat, ensuring image quality, and network adaptability as well.