[MPlayer-users] motion vectors from p frames

[mark]

Hi
I am trying to grab motion vectors, from all the p frames of a 3gp
sequence. I am using mplayer [I have configured it to play 3gp video],
and I am having problem getting the motion vectors.

mplayer -lavdopts debug=32 xx.3gp

should give the motion vectors, if I what I understood from the man of
mplayer is right.

But when i do this, I do not get any motion vectors. The video just plays.

However, I am able to visualize the motion vectors using the option
-lavdopts vismv=1.
But I need the motion vector data. Can anyone suggest what I should do?

thanks
mark