An efficient intra block size decision for H.264/AVC encoding optimization

Abstract

The video coding standard, H.264/MPEG-4 AVC, uses variable block sizes in intra coding. This feature has achieved significant coding gain compared to coding a macroblock (MB) using fixed block size. However, this feature results in extremely high computational complexity when brute force rate distortion optimization (RDO) algorithm is used. In this paper, we propose an Efficient Intra Block Size Decision for H.264/AVC Encoding Optimization. It makes use of the spatial homogeneity characteristics of the macroblock. Specifically, spatial homogeneity of a MB is decided based on the amplitude value of the proposed MB vector. Based on the homogeneity of the macroblock, only a small number of intra prediction modes are selected in the RDO process. Different video sequences are used to test the performance of proposed method. Experimental results reveal the significant computational savings achieved with slight Peak Signal-to-Noise Ratio (PSNR) degradation and bit-rate increase.