Effiecient WZ-to-H264 transcoding using motion vector information sharing

In mobile-to-mobile video communications, both the sender and the receiver devices should not have higher complexity requirements to perform complex video compression tasks. The traditional video coding solutions are not suitable to support this communications due to its extremely complex encoding algorithm. On the other hand, the new Wyner-Ziv video coding paradigm reduces the complexity of the encoder at the expenses of a more complex decoder. In this paper, we propose an improved WZ/H.264 video transcoder to support this mobile-to-mobile communications, using the low complexity Wyner-Ziv encoding and the traditional H.264 decoding to be implemented in the end-user devices. The improved transcoder converts the video from the Wyner-Ziv to H.264 and reuses the motion vectors generated in the Wyner-Ziv decoding, in order to reduce the computational complexity of the motion estimation process in the H.264 encoding. Simulations results show a complexity reduction up to 55% with negligible rate-distortion drop.