Bit allocation for joint spatial-quality scalability in H.264/SVC

In this work, we propose a model-based layer bit allocation algorithm for joint spatial-quality (S-Q) scalability in H.264/SVC. The complicated inter-layer dependency is decoupled by the proposed spatial and quality rate and distortion (R-D) models. We show that the R-D characteristics of a dependent layer can be represented by a number of independent functions with GOP as a basic coding unit. Then, the joint bit allocation problem is formulated as a two-step optimization problem by the Lagrangian multiplier method, which can be numerically solved using the proposed R-D models. Finally, we develop a low-complexity bit allocation algorithm for the combined spatial and quality scalability in H.264/SVC. It is shown by experimental results that our proposed bit allocation algorithm achieves the coding performance significantly improved from current reference software JSVM.