A method of processing a bitstream of coded data of video sequences of progressive
or interlaced pictures includes estimating motion vectors of groups of pixels.
These groups of pixels belong to a top half-frame of the current picture in relation
to pixels belonging to a bottom half-frame of a preceding picture. Motion vectors
are also estimated for group of pixels of a bottom half-frame of the current picture
in relation to pixels belonging to the top half-frame of the current picture. The
processing calculates for each macroblock of a top half-frame and a bottom half-frame
a respective top motion coefficient and a bottom motion coefficient depending on
the estimation of the motion vectors of the top half-frame and the bottom half-frame.
The current picture is recognized as an interlaced picture by a substantial equality
of the distributions of values of the motion coefficients, or as a progressive
picture by a substantial inequality of the distributions of values of the motion coefficients.
