Efficient rate allocation algorithms for MPEG-4 FGS coded video using piecewise rate distortion model

Rate allocation algorithm for the MPEG-4 Fine granular scalability (FGS) enhancement layer is an important tool in MPEG-4 FGS-based video streaming applications. Based on the fact that the Rate-distortion (R-D) curve of the MPEG-4 FGS enhancement layer exhibits piecewise characteristics, and each piecewise region of the curves corresponds to a different bit plane in the enhancement layer, a first-order or a second-order model is adopted to estimate the actual R-D, curve for each piecewise region. Then, three efficient rate allocation methods are proposed to allocate an appropriate number of bits to the enhancement layer of each frame so as to achieve the constant quality. Experimental results show that, compared to the average rate allocation method and the exponential model method, our proposed algorithms can achieve a much constant quality in the reconstructed video. Complexity analysis also shows that our proposed methods are efficient and require little computation at the video server. Therefore, they are practical for video streaming applications.