Medium-granularity computational complexity control for H.264/AVC

Today, video applications on handheld devices become more and more popular. Due to limited computational capability of handheld devices, complexity constrained video coding draws much attention. In this paper, a medium-granularity computational complexity control (MGCC) is proposed for H.264/AVC. First, a large dynamic range in complexity is achieved by taking 16×16 motion estimation in a single reference frame as the basic computational unit. Then a high coding efficiency is obtained by an adaptive computation allocation at MB level. Simulations show that coarse-granularity methods cannot work when the normalized complexity is below 15%. In contrast, the proposed MGCC performs well even when the complexity is reduced to 8.8%. Moreover, an average gain of 0.3 dB over coarse-granularity methods in BD-PSNR is obtained for 11 sequences when the complexity is around 20%.