Size-controllable memory reduction scheme of storing reference frames at H.264/AVC under I, P and B

In H.264/AVC, multiple reference frames are adopted to enhance inter-predictive coding efficiency of motion estimation/compensation. However, memory cost is also increased with the number of used reference frames. This work presents a size-controllable memory reduction method to accommodate multiple reference frames at a limited memory size. This scheme is to store some of Macro-Blocks (MBs) as compressed data from their partially decoded bit streams, and the other as the reconstructed data. An effective compromise mechanism between amounts of compressed and reconstructed data is developed to meet the memory constraint by minimizing the computation required. Simulation results demonstrate that the proposed method can make a good use of constrained memory to store multiple reference frames of H.264/AVC at I, P and B. As compared to the conventional methods, the proposed method can easily adapt to the amount of the constrained memory, above 95% usage rate, and yield around 3~6 dB improvement on PSNR at fair computation cost.