Motion refined medium granular scalability In this paper, we propose an interesting scheme to obtain a good tradeoff between motion information and residual information for medium granular scalability (MGS). In this scheme, both motion information and residual information are refined at enhancement layers when the scalable bit rate range is wide, whereas only residual information is refined when the range is narrow. In other words, for the case of wide bit rate range, there can be more than one motion vector fields (MVFs) where one is generated at base layer and others are generated at enhancement layers. When it is narrow, only one MVF is necessary. The layers can either share one MVF or have its own, depending on the bit rate range cross layers. Unlike Coarse Granular Scalability (CGS), the correlation between two adjacent MVFs in MGS is very strong. Hence MGS can be provided in the most important bit rate range to achieve a better tradeoff between motion and residual information and a finer granularity in that range. CGS can be applied in less important bit rate ranges to give a coarse granularity. Experimental results show that the coding efficiency can be improved by up to 1dB compared with existing SNR scalability scheme at high bit rate.

Improvements of multiple FGS layers coding for lowdelay applications in SVC For lowdelay applications in Scalable Video Coding, there are two alternative coding strategies based on ARFGS for compressing multiple FGS layers. However, their coding efficiencies both suffer largely from the inherent drifting errors. In this paper, a more efficient multiple FGS layers coding structure is presented, which can provide higher coding performance within wide bitrate range and stronger error resilience. This is achieved by incorporating the partialreconstructed enhancement layer references, instead of the completereconstructed ones, into the motioncompensated prediction loop of the FGS layers. Thereupon the prediction drift can be effectively decreased, especially for the middle bitrate points. Further, through selecting differentquality enhancement layer references generated with cyclebased reconstruction mechanism, more flexible video quality can be supported to be more suitable for varied practical application requirements.