Multilevel video coding and distribution architectures for emerging broadband digital networks

There is a renewed interest in video-based communications. The expected proliferation of various video communication applications has in turn resulted in a need for scalable and efficient digital video encoding schemes which would enable the dissemination of video signals at differing spatial resolution, depending on end-user needs and limitations. Also, along with this is the need for a universal broadband in which the same transmitted signal is efficiently distributed to various end-user applications, allowing them to communicate at differing grades of video quality. As a first step, this paper presents an efficient and scalable video coding scheme. The scheme is capable of encoding and decoding video signals in a hierarchical, multilayer fashion to provide video at differing quality grades, e.g., NTSC, extended quality (EQTV), high definition (HDTV). Since the lower levels in such a scheme can be encoded independently of the upper levels, compatibility with some of the standard codecs can be directly imposed. In addition, strategies to control quantization noise for independent transmission by means of residual layering are also discussed. This paper also discusses the utilization of this coding scheme to enable efficient bit rate sharing and robust distribution of video communication signals at three distinct quality grades in multicasting, as well as multipoint communication applications for multiparty video-conferencing. Two special distribution architectures are considered which involve the use of SMDS and ATM as the transport and delivery vehicles.