A fast downsizing video transcoder based on H.264/AVC standard

Abstract

This paper presents a novel spatial transcoding technique for H.264/AVC based video applications. With superior coding performance, H.264 will be used in a variety of multimedia applications. For various video applications, spatial transcoding techniques can facilitate compact storage of video sequences with specified resolution and bitstream format. Under demands, we can convert the archival bitstreams to another bitstream with different bitrates and different resolution before transmission. For H.264 video transmission that needs spatial resolution conversion, we propose a bottom-up motion vector re-estimation, rapid rate-distortion (R-D) optimized mode decision, and adaptive motion search range to speed up the spatial transcoding and retain visual quality of transcoded video. The results show that the fast transcoder has the R-D performance close to or better than R-D re-encoding algorithm, which has the highest complexity and best coding efficiency. © Springer-Verlag 2004.