A fast macroblock mode decision scheme using ROI-based coding of H.264/MPEG-4 Part 10 AVC for mobile video telephony applications

Abstract

ABSTRACT We propose a fast macroblock mode decision scheme in the H.264|MPEG-4 Part 10 Advanced Video Coding (AVC) for mobile video telephony applications. In general, the face region around a speaker is considered region of interest (ROI) while the background is not importantly considered, thus being regarded as non-ROI for the video telephony situations. We usually have to consider the following two issues: (1) the platforms of mobile video telephony are usually computationally limited and the AVC codecs are computationally expensive; and (2) the allowed channel bandwidths are usually very small so the compressed video str eams are transmitted with visual quality degraded. In this paper, we challenge the two issues: Firstly, a fast macroblock mode decision scheme is contrived to alleviate the computational complexity of H.264|MPEG-4 Part 10 AVC; and secondly, ROI/non-ROI coding of H.264|MPEG-4 Part 10 AVC is incorporated to enhance subjective visual quality by encoding ROI data in higher quality but non-ROI data in lower quality. Our proposed fast macroblock mode decision scheme consists of three parts: early skip mode detection, fast inter macroblock mode decision and intra prediction skip parts. The skip mode detection method is to decide whether or not to perform the rest inter macroblock modes in P-Slices. The fast inter macroblock mode method is to reduce the candidate block mode by SATD