A Novel Joint Rate Allocation Scheme of Multiple Streams.

Encoding multiple videos in parallel and transmitting them as one joint stream over a limited bandwidth have become a popular strategy for broadcasting, which brings an opportunity to allocate different bitrate for each sequence to meet different demands. In this paper, considering visual experience for human beings, we propose a joint rate allocation scheme aims to reach an equal visual quality among all sequences by minimizing the distortion variance of all the sequences (denoted as minVAR problems). Existing methods assigned bits directly in proportion to their complexity measures and we named them as complexity based allocation scheme (CAS) methods. CAS methods rely on the accuracy of the complexity measures which can hardly be improved under limited computing resources. Also complexities may not be directly related to the distortions. To address these problems, we present a novel joint rate-distortion (R-D) based allocation scheme (RDAS) in this paper. Our proposed scheme can fit for different R-D models and in our method we model the R-D relationship with a hyperbolic function (RDAS-H). We also derive a closed-form solution of RDAS-H by a proposed joint R-D relationship. We integrated the RDAS-H method in high efficiency video coding reference software HM16.0. Experimental results demonstrate that our RDAS-H saves 75.29% variance on average over the related CAS-based method, where we apply both low delay and random access configurations with four different overall bandwidths for all classes recommended by the Joint Collaborative Team on Video Coding. Besides, RDAS-H also saves 36.62% variance on average over our previous method. The proposed RDAS-H method improves the performance significantly while requiring negligible computational cost. [ABSTRACT FROM AUTHOR]