Low-complexity rate control based on ρ-domain model for Scalable Video Coding
In this paper, we present a novel low complexity yet very efficient rate control algorithm for Scalable Video Coding (SVC) based on the ρ-domain model. Compared with the conventional ρ-domain model in determining quantization parameter, the proposed algorithm adopts a new linear model to obtain the quantization parameter at frame-level. This linear model is able to characterize the relationship between the percentage of zero among quantized coefficients and the quantization step. Since this model considers the Mean Absolute Difference (MAD) of each frame, individual frame only needs to be encoded once to control the bit-rate. In particular, the model parameter in the ρ-domain model can be adaptively estimated by utilizing either temporal or inter-layer information. This leads to significant improvement in estimation accuracy. Experimental results show that the proposed algorithm can achieve accurate bit-rate and maintain the maximum mismatch between actual bit-rate and target bit-rate within 0.5%. More importantly, the proposed low complexity algorithm is able to obtain PSNR improvement up to 0.6dB comparing with the algorithm adopted in the Joint Scalable Video Model (JSVM).