Scalable Video Coding

With the evolution of Internet to heterogeneous networks both in terms of processing power and network bandwidth, different users demand the different versions of the same content.This has given birth to the scalable era of video content where a single bitstream contains multiple versions of the same video content which can be different in terms of resolutions, frame rates or quality.Several early standards, like MPEG2 video, H.263, and MPEG4 part II already include tools to provide different modalities of scalability.However, the scalable profiles of these standards are seldom used.This is because the scalability comes with significant loss in coding efficiency and the Internet was at its early stage.Scalable extension of H.264/AVC is named scalable video coding and is published in July 2007.It has several new coding techniques developed and it reduces the gap of coding efficiency with state-of-the-art non-scalable codec while keeping a reasonable complexity increase.After an introduction to scalable video coding, we present a proposition regarding the scalable functionality of H.264/AVC, which is the improvement of the compression ratio in enhancement layers (ELs) of subband/wavelet based scalable bitstream.A new adaptive scanning methodology for intra frame scalable coding framework based on subband/wavelet coding approach is presented for H.264/AVC scalable video coding.It takes advantage of the prior knowledge of the frequencies which are present in different higher frequency subbands.Thus, by just modification of the scan order of the intra frame scalable coding framework of H.264/AVC, we can get better compression, without any compromise on PSNR.This chapter is arranged as follows.We have presented introduction to scalable video in Section 2, while Section 3 contains a discussion on scalable extension of H.264/AVC.Comparison of scalable extension of different video codecs is presented in Section 4. It is followed by adaptive scan algorithm for enhancement layers (ELs) of subband/wavelet based scalable architecture in Section 5.At the end, concluding remarks regarding the whole chapter are presented in Section 6. Basics of scalabilityHistorically simulcast coding has been used to achieve scalability.In simulcast coding, each layer of video is coded and transmitted independently.In recent times, it has been replaced by scalable video coding (SVC).In SVC, the video bitstream contains a base layer and number of enhancement layers.Enhancement layers are added to the base layer to further enhance the quality of coded video.The improvement can be made by increasing Scalable Video Coding