A complexity-scalable transcoder from H.264/AVC to the new HEVC codec

The emerging video coding standard, HEVC, is currently approaching the final stage of development prior to standardization. However, the current H.264/AVC standard is very successful, and it has been widely adopted for many applications. Thus, transcoding between these codecs will be highly needed once the HEVC codec is finalised. This paper studies the performance of one of the most common techniques for heterogeneous transcoding, motion vector (MV) reuse, in a H.264/AVC to HEVC transcoder. Furthermore, it proposes a new transcoder that is capable of complexity scalability, trading off rate-distortion performance for complexity reduction. The proposed transcoder is based on a new metric to compute the similarity of the H.264/AVC MVs, which is used to decide which HEVC partitions are tested on the transcoder.