A fast algorithm of bitstream extraction using distortion prediction based on simulated annealing

Scalable video streams can be extracted to meet the bandwidth limitation of different networks and end-users. Bitstream extraction is usually performed at the network proxy or gateway during transmission, where a low computational complexity is always preferred. How to quickly and accurately select the best resolution combination for a video to meet different bandwidth requirements by each user is crucial in bitstream extraction. In this paper a fast algorithm of bitstream extraction for scalable video is proposed. The interlayer dependency between the base quality layer and the first quality layer was used to predict the distortion of higher quality layers. When quality of every layer is available, the proposed method searches for the optimized combination of quality layers based on simulated annealing. Experimental results show that the proposed method provides an optimized performance, which is significantly higher than that can be achieved by the basic extraction method. Compared to the quality layer based extraction method in the reference software model of H.264/SVC (i.e., JSVM), the proposed algorithm can greatly decrease the decoding times from 2NT to only 2 without losing rate-distortion performance. Furthermore, the proposed method obtains a more smoothed video quality which is always favorable to the observer.