The Design And Optimization Of A Hybrid Video Codec Based On H.264/AVC Platform

The Next generation video compression standard H.264/AVC (ITU-T Recommendation H.264 and ISO/IEC MPEG-4 (part 10) Advanced Video Coding) is known as the newest video coding standard generated by the Joint Video Team (JVT) composed of ITU-T VCEG and ISO/IEC MPEG. It is designed to compress the source images and videos with lower distortion, less bit rates and higher compression ratio in the applications as many as possible instead of the present standard---MPEG-4 (part 2). Based on the traditional frame and block segmentation coding architecture, H.264/AVC adopts many advanced algorithms, such as adaptive integer transform, enhanced motion estimation and compensation, adaptive loop filter, enhanced entropy coding, etc. With these algorithms, H.264/AVC makes a perfect balance between the computation complexity and the coding performance. Additionally, considering the simplicity and the cost for the hardware implementations, the new standard puts much emphasis on the VLSI (Very Large Scale Integration) implementations.However, In order to adapt to almost all the practical environments, this standard does not have enough technical optimizations in detail to the different applications in the coding process, so under some special conditions, H.264/AVC can not get the highest performance as it is designed to. In the other hand, H.264/AVC only makes standardizations in the end of the decoder, and leaves a big enough space for optimization by different organizations for different purposes.Based on the deep research of H.264/AVC, some basic principles of designing a modern hybrid video codec are proposed comparing H.264/AVC with the traditional coding standards. Some modifications, including the modified motion segmentation mode, the modified integer transform strategy, the modified rate-distortion equation and the modified fast motion search strategy, are made to H.264/AVC codec in order to increase the performance.The experiment results present that these modifications are valuable both in the areas of the theory and the real applications.