Present and Future Video Coding Standards

Video coding systems may greatly differ from each other, as they consist of complicated functional modules and each module can be realized by using different techniques. For the interoperability in communication, video coding standards are developed to restrict various video coding systems, such that manufacturers can successfully interwork with each other by producing compliant encoders and decoders, and at the same time still have the freedom to develop competitive and innovative products. A standard defines a coded representation, syntax, which describes the video in a compressed form. In other words, a standard only specifies the output of the encoder, i.e., the input of the decoder, instead of the codec itself. Although the standard also provides a method of decoding the syntax to reconstruct the video, the manufacturers are free to develop alternative decoders as long as they can decode the syntax and produce the same result as that in the standard. Video coding standards have been developing for about 20 years, driven by applications and advances in hardware capability. This chapter begins with an introduction of the block-based hybrid coding scheme, which is essentially the core of all the video coding standards. In Section 2, the past video coding standards are briefly reviewed, including H.261, MPEG-1, MPEG-2/H.262, H.263, and MPEG-4. The latest standard, H.264/AVC, is the emphasis of this chapter, which is introduced in Section 3, including the new technical developments and profiles favoring a wide range of applications. The recently finalized amendments on scalable video coding (SVC) and multiview video coding (MVC) are another two highlights. Section 4 presents the Audio and Video Coding Standard (AVS) of China, which has received much attention throughout the world, even though it is a national standard. Finally, Section 5 introduces the current topics intensively studied in the standardization groups, which may become the key techniques in the future coding standards.