Macroblock mode decision for H.264

A complexity reduction algorithm for an H.264 encoder is proposed. This comes at the cost of the number of increased macroblock modes and the complex mode decision procedure using the rate-distortion optimization [1]. Computational savings are achieved by identifying, prior to motion estimation, macroblocks that are likely to be skipped and hence saving futher computational processing of these macroblocks. This early prediction is made by estimating a Lagrangian rate-distortion cost function. In this paper, we propose a fast mode decision algorithm using mode classification for H.264/AVC. Simulation results show that the proposed algorithm can reduce the encoding time by 29.67% on average and the rate-distortion computation complexity by 89,14% (depending on the source sequence) with no significant loss of rate-distortion performance.