Rate-distortion-smoothness optimized rate allocation schemes for Spectral Fine Granular Scalable video coding technique

Spectral Fine Granular Scalability (SFGS), a variation of MPEG-4 FGS, is proposed in this paper as a scalable coding technique for video streaming. SFGS re-arranges enhancement-layer bit-plane data according to spectral frequency orderings before they are further processed with traditional FGS bit-plane coding technique. Based on this data reordering within each bit-plane, spectral bands of lower frequency or higher rate-distortion properties are transmitted with priorities. In spite of this modification, SFGS retains similar properties as FGS, such as the coding efficiency, error resilience, and adaptation to channel bandwidth variation. However, SFGS is promising in yielding evener image quality and smoother video perception at the receiver side when the channel bandwidth is limited. Traditional FGS rate control techniques lack a systematic approach to making tradeoffs between image quality, motion smoothness (i.e., the frame rate), and video smoothness (PSNR difference between consecutive frames), according to limitations on system resources and users’ preferences. In view of this drawback, we propose here a unified rate allocation scheme, based on rate-distortion-smoothness optimization criterion and multi-stage dynamic programming (DP) technique, to solve the above problems. Experiments show that our algorithm is capable of achieving a smoother video quality, and simultaneously guaranteeing no buffer overflow and underflow at encoder/decoder, under a target bit-rate constraint. Though our proposed algorithm was designed for SFGS, it can be also applied to other FGS variations.