Fine granularity in multi-loop hybrid coders with multi-layer scalability

The paper describes a generic multi-loop coder structure suitable for mixed spatial and temporal scalability combined with fine granular SNR scalability. The structure is suitable for various variants of hybrid video coders like MPEG-2, H.263 and H.26L. The idea of mixed spatial and temporal scalability i.e. spatio-temporal scalability is substantial for the proposal. Its application allows improving the scalable coding efficiency i.e. decreasing the scalability overhead. The coder consists of independently motion-compensated sub-coders that produce bitstreams corresponding to individual levels of spatio-temporal resolution. The bitrate can be smoothly matched to the particular channel bandwidth by use of data partitioning, which is related to drift errors in the decoder. Accumulation and propagation of these errors can be bounded by use of proper structures of groups of pictures.