Rate-GOP Based Rate Control for High Efficiency Video Coding
In this paper, a Rate-GOP based frame level rate control scheme is proposed for High Efficiency Video Coding (HEVC). The proposed scheme is developed with the consideration of the new coding tools adopted into HEVC, including the quad-tree coding structure and the new reference frame selection mechanism, called reference picture set (RPS). The contributions of this paper mainly include the following three aspects. Firstly, a RPS based hierarchical rate control structure is designed to maintain the high video quality of the key frames. Secondly, the inter-frame dependency based distortion model and bit rate model are proposed, considering the dependency between a coding frame and its reference frame. Thus the distortion and bit rate of the coding frame can be represented by the distortion and bit rate of its reference frame. Accordingly, the Rate-GOP based distortion model and rate model can be achieved via the inter-frame dependency based distortion model and bit rate model. Thirdly, based on these models and a mixed Laplacian distribution of residual information, a new ρ-domain Rate-GOP based rate control is proposed. Experimental results demonstrate the proposed Rate-GOP based rate control has much better R-D performance. Compared with the two state-of-the-art rate control schemes for HEVC, the coding gain with BD-PSNR can be up to 0.87 dB and 0.13 dB on average respectively for all testing configurations. Especially for random access low complexity testing configuration, the BD-PSNR gain can be up to 1.30 dB and 0.23 dB respectively.