Advanced Video Technologies and Applications for H.264/AVC and Beyond

Copyright © 2006 Jar-Ferr (Kevin) Yang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The recently developed video coding standard, H.264/AVC, significantly outperforms previous standards in terms of coding performance at reasonable implementation complexity. Several application systems, such as high-definition DVD and digital video broadcasting for handheld devices and high-definition television systems, have adopted H.264 or its modified versions as the video coding standard. In addition , the extensions of H.264/AVC to scalable and mul-tiview video coding applications are nearly finalized. Many video services, especially bandwidth-limited wireless video, will benefit from the H.264 coder due to its outstanding features. The use of variable block sizes for intra-and inter-prediction in combination with different intra-prediction modes and motion compensation using multiple reference frames is one of the main reasons for the improved coding efficiency in H.264/AVC. Together with many other new features , the encoder can select between multitudes of different coding modes. The determination of the optimal coding mode under the joint rate and distortion consideration, which is called the rate-distortion optimization (RDO), introduces a huge amount of memory access and computational complexity for testing all possible modes in video encoders. Hence, a reduction of the complexity of motion estimation and mode selection in an H.264/AVC encoder becomes an important task for real-time applications. In selecting the quantization parameters at the frame and the block levels, the goal is to design a rate-control method that maximizes the video quality with a constrained bandwidth. Regardless of the superior coding efficiency of the H.264/AVC standard, there still exist many video coding standards. For example, MPEG-2 and H.263 have been adopted by the current television and video tele-phony systems, respectively. Therefore, an effective transcod-ing method, which can effectively convert the existing non-H.264 bitstreams to H.264 conforming bitstreams, while maintaining the excellent rate-distortion performance, will greatly smooth the transition in the migration to H.264/AVC. Compressed video is typically the most demanding component in modern multimedia services. The statistical analysis on H.264/AVC bitstreams will help to precisely characterize the traffic in video communication. Furthermore, the accurate prediction of dynamic bandwidth allocation of video encoders in network utilization is also important to achieve the best quality of service (QoS). Over wireless and Internet communications, transmission rate variations and transmission-error/packet-loss are inevitable during video …