Complexity Based Fast Coding Mode Decision for MPEG-2 / H.264 Video Transcoding

The coexistence of MPEG-2 and its powerful successor H.264/AVC has created a huge need for MPEG-2/H.264 video transcoding. This paper proposes a 2D Sobel filter based motion vector domain method and a DCT domain method to measure macroblock complexity and realize efficient H.264 candidate mode decision. A new local edge based fast INTRA prediction mode decision method is also adopted to boost the encoding efficiency. Simulation results confirm that with the proposed methods the computational burden of a traditional transcoder can be reduced by 20% ~ 30% with only a negligible bit-rate increase for a wide range of video sequences