Managing drift in DCT-based scalable video coding

When compressed video is transmitted over erasure-prone channels, errors will propagate whenever temporal or spatial prediction is used. Typical tools to combat this error propagation are packetization, re-synchronizing codewords, intra-coding, and scalability. In recent years, the concern over so-called "drift" has sent researchers toward structures for scalability that do not use enhancement-layer information to predict base-layer information and hence have no drift. In this paper, we propose alternative structures for scalability that use previous enhancement-layer information to predict the current base layer, while simultaneously managing the resulting possibility of drift. These structures allow better compression efficiency, while introducing only limited impairments in the quality of the reconstruction.