Motion vector (MV) data coding is important to the
performance of video coding, especially for codecs with a high
level of MV accuracy (1/4 or 1/8 pel). For this reason, MV
coding and decoding is quite complicated, since significant gains
in efficiency can be
made by choosing a good prediction and entropy coding
structure. The basic format of the MV coding module is similar
to the coding of coefficient data: it consists of prediction,
followed by binarisation, context modelling and adaptive
arithmetic coding: