In-Layer Multibuffer Framework for Rate-Controlled Scalable Video Coding

Temporal scalability is supported in scalable video coding (SVC) by means of hierarchical prediction structures, where the higher layers can be ignored for frame rate reduction. Nevertheless, this kind of scalability is not totally exploited by the rate control (RC) algorithms since the hypothetical reference decoder (HRD) requirement is only satisfied for the highest frame rate substream of every dependence (spatial or coarse grain scalability) layer. In this paper, we propose a novel RC approach that aims to deliver several HRD-compliant temporal resolutions within a particular dependence layer. Instead of using the common SVC encoder configuration consisting of a dependence layer per each temporal resolution, a compact configuration that does not require additional dependence layers for providing different HRD-compliant temporal resolutions is proposed. Specifically, the proposed framework for rate-controlled SVC uses a set of virtual buffers within a dependence layer so that their levels can be simultaneously controlled for overflow and underflow prevention while minimizing the reconstructed video distortion of the corresponding substreams. This in-layer multibuffer approach has been built on the top of a baseline H.264/SVC RC algorithm for variable bit rate applications. The experimental results show that our proposal achieves a good performance in terms of mean quality, quality consistency, and buffer control using a reduced number of layers.