Optimized Bit Extraction Using Distortion Estimation in the Scalable Extension of H.264/AVC

The newly adopted scalable extension of H.264/AVC video coding standard (SVC), demonstrates significant improvements in coding efficiency in addition to an increased degree of supported scalability relative to the scalable profiles of prior video coding standards. For efficient adaptation of SVC bit streams to intermediate bit rates, the concept of quality layers has been introduced in the design of the SVC. The concept of quality layers allow a rate distortion (RD) optimal bit extraction; However, existing Quality Layer assignment methods do not consider all network abstraction layer (NAL) units from different layers for the optimization. In this paper, we first propose a technique to accurately and efficiently estimate the quality degradation resulting from discarding an arbitrary number of NAL units from multiple layers of a bitstream. Then, we utilize this distortion estimation technique to assign quality layers to NAL units for a more efficient extraction. Experimental results show that a significant gain can be achieved by the proposed schemes.