A Temporal Dependency Model for Rate-Distortion Optimization in Video Coding

Many video codecs use motion compensated prediction to achieve compression efficiency. Motion compensated prediction may produce temporal dependency across frames. For example, quantization distortion in a block may propagate through motion compensated prediction and affect the coding efficiency of blocks in subsequent frames. Identifying temporal dependencies may improve the rate-distortion optimization and produce coding performance gains. Block-based motion trajectories and correlations between source pixel blocks along a motion trajectory may be used estimate a distortion propagation model, which may represent the correlation between the distortion propagation and the effect of quantization. A temporal dependency model that accounts for both block correlation and the quantization effect may provide compression gains over the use of a distortion propagation model