Two-Level Segment-Based Bitrate Control for Live ABR Streaming

Adaptive Bitrate (ABR) streaming has been widely used on OTT live streaming services. However, most OTT still use the traditional rate control developed for delivering a continuous bitstream, which can’t achieve the best performance of ABR technology. In this paper, a two-level segment-based rate control for ABR streaming is proposed. In the segment level, we properly allocate the bits to frames depend on their types and content complexity; while in the picture level, the proposed algorithm controls the encoded picture size close to the allocated size by an improved rate prediction model. Experimental results on two representations demonstrated that the fluctuation of segment size generated from proposed algorithm can reduce from 7.615% to 0.76% compared to x264, and the PSNR can increase 0.92 dB in average.