[vlc] wrong fps during the play

[Giovanni Venturi]

Hello,
I've got an m4v file that on VLC doesn't play correctly I tryed it on VLC 1.0.2 and 1.1.4 on Linux 
and on 0.9.8a and 1.1.4 on Windows. The result is the same, so it's a generic VLC issue. In the 
information of the media VLC says 100 frame per second, but opening it on mplayer it says about 7 
fps, so mplayer reproduces it correctly with its ~7 fps and VLC plays it very quickly with its 100 
fps. Why the fps detection is not correct on VLC? How can I set it manually? I tryed the option --
vc1-fps using 7 as value, 0.25 as value, but the parameter is ignored. How can I do? What is the 
correct option?
The fps is something that is written into the original file? I suppose it's evalued by the software 
that plays the clip. How is determined by VLC?
Thank you,
Giovanni