Fast and memory-efficient up-sampling methods for H.264/AVC SVC with extended spatial scalability

The inter-layer prediction (ILP) including intra, residual, and motion up-sampling operation in SVC significantly increased the compression ratio compared with simulcast. The up-sampling algorithms of ILP, however, require much more memory and computational load than single-layer coding because they require several large buffers for storing up-sampled data, four-tap FIR filter, and many conditional branches, et al. This paper presents macroblock (MB)-based up-sampling methods using just-in-time strategy, where intra and residual up-sampling operations for extended spatial scalability (ESS) are selectively performed by using MB information of enhancement layer. Especially, residual up-sampling operations are largely simplified by determining transform block identification for only luma plane and by calculating and referencing the identification per 4×4 block instead of pixel. Experimental results show that the proposed algorithms speed-up the total decoding time of 3-layer (SIF/SD/Full-HD) sequences by about 64% on average and reduce the memory consumption required for up-sampling operations by about 99%, compared with the existing picture-based up-sampling algorithm for ESS.