  Motion estimation is a key component of any modern video codec. Our
understanding of motion and the estimation of motion from video has come a very
long way since 2000. More than 135 different algorithms have been recently
reviewed by Scharstein et al http://vision.middlebury.edu/flow/. These new
algorithms differ markedly from Block Matching which has been the mainstay of
video compression for some time. This paper presents comparisons of H.264 and
MP4 compression using different motion estimation methods. In so doing we
present as well methods for adapting pre-computed motion fields for use within
a codec. We do not observe significant gains to be had with the methods chosen
w.r.t. Rate Distortion tradeoffs but the results reflect a significantly more
complex interrelationship between motion and compression than would be
expected. There remains much more to be done to improve the coverage of this
comparison to the emerging standards but these initial results show that there
is value in these explorations.
