On H.264/AVC Video Coding And Its Error Control Technology

The H.264/MEPG-4 Advanced Video Coding standard (H.264/AVC) is the newest video coding standard jointly developed by the ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts Group (MPEG). H.264/AVC has achieved a significant improvement in compression performance compared to prior standards, and it provides a network-friendly representation of the video that addresses both conversational (video telephony) and nonconversational (storage, broadcast, or streaming) application.In the video-encoding process, the encoding time is greatly influenced by many factors, such as inter/intra mode decision, motion estimation (ME), etc. In order to encode the video with faster speed and better quality, this paper only focuses on the intra mode decision in H.264/AVC and presents a fast intra prediction mode decision algorithm for 4×4 blocks in H.264/AVC. The proposed algorithm uses: (i) high correlation of RD cost between best prediction mode and its neighborhood prediction mode, (ii) strong correlation between sums of absolute transform differences (SATD) and rate distortion (RD) performance, efficiently skipping some unlikely prediction modes. Thus, it can complete 4×4 intra prediction by only computing RD cost for four times. The experimental results show that the proposed algorithm is a good compromise between the coding performance and the encoding speed.Video transmission over wireless network and IP network can suffer from errors, due to fluctuating channel conditions, which appear in the form of packet erasures. This paper only focuses on the intra frame and presents a highly effective spatial error concealment algorithm that can be used on intra macroblocks in H.264/AVC. It uses the direction information of neighboring edges for deciding between DI (ensuring edge preservation) and BI (avoiding the creation of false edges). The experimental results show that the proposed algorithm can preserves edges and textured areas without creating new false ones, and give better subjective (and objective) quality over the commonly used weighted pixel value averaging.