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Rate control for MPEG-4 FGS coded video using piecewise rate distortion model

Three efficient rate allocation schemes for the MPEG-4 fine granular scalability (FGS) enhancement layer with constant quality are proposed. With the distortion measured using the mean squared error (MSE) or peak signal-to-noise ratio (PSNR) metric, the rate distortion (R-D) curve of the MPEG-4 FGS enhancement layer exhibits piecewise characteristics. For each piecewise region, a first-order or a second-order model is adopted to estimate the actual R-D curve. Based on these piecewise models, three optimal rate allocation schemes are proposed to allocate an appropriate number of bits to the enhancement layer of each frame. Experimental results show that, compared to the average rate allocation method and the exponential model method, our proposed algorithms can achieve a more constant quality in the reconstructed video.