Fast mode decision of downscaling video transcoding for H.264 streams

Abstract

The H.264 coding standard adopts some novel features such as intra prediction,and variable block size to achieve higher coding efficiency at the sacrifice of computational complexity,so the algorithm of mode decision will remarkable affect the efficiency of video transcoding based on H.264.A fast mode decision algorithm of spatial downscaling trnascoder for H.264 video stream was proposed.It utilized the local prediction direction and the gradient to reduce the number of candidate modes.The experimental results demonstrate that it can reduce the complexity of mode decision in downscaling video transcoding while keeping the quality of reconstructed video and coding efficiency.