Exploiting interlayer correlation of SNR scalable video

There is a significant interlayer correlation between the base and enhancem ent layers of two-layer signal-to-noise-ratio (SNR) scalable coders, By del aying the enhancement-layer bitstream, spatial and temporal interlayer corr elations can be minimized or even made negative. Such an arrangement improv es the statistical multiplexing gain to the extent that, even taking into a ccount the normally higher bit rate of SNR scalable coders, negatively corr elated two-layer sources tan be more efficiently multiplexed than their sin gle-layer counterparts, Simulation results suggest that decorrelation be ap plicable to both weakly and strongly aligned Sources and by inferences to a ny randomly aligned sources there between, Greatest "gains" in cell-loss ra tio (CLR) are displayed by strong alignments such that for videoconferencin g-type pictures, SNR scalable sources were able to raise aggregate bit rate s by up to 38% before overall CLR started to fall below a single-layer perf ormance of 10(-4) With correlation dependent on the base/enhancement-layer division of bandwidth, only when the enhancement-layer efficiency is at its worst (close base and enhancement quantizer indexes) is the decorrelation "gain" insufficient to compensate the increase in total SNR scalable coder bit rate.