Quality scalability in H.264/AVC video coding

It is well-known that the problem of addressing heterogeneous networks in multicast can be solved by simultaneous transmission of multiple bitstreams of different bitrates and by layered encoding. This paper analyzes the use of H.264/AVC video coding in simulcast and for layered encoding. The sub-sequence feature of H.264/AVC enables hierarchical temporal scalability, which allows disposal of reference pictures from a coded bitstream without affecting the decoding of the remaining stream. In this paper we extend the scope of the H.264/AVC sub-sequence coding technique to quality scalability. The resulting quality scalable coding technique is similar to conventional coarsegranularity quality scalability but fully compatible with the H.264/AVC standard. It is found that the proposed method drops bitrate consumption in the core network compared to simulcast up to 20%. However, the bitrate required for enhanced-quality reception for scalably coded bitstreams is considerably higher than that of non-scalable bitstreams.