[MPlayer-dev-eng] problem with mpeg-sinc

[elcabesa]

i'm trying to use mencoder and to encode form a dvd  , and i want to use the 
-ss optoin in menocder
but it's not very precise...   looking how demux_seek_mpg work i saw that if 
mpeg video has not a constant bitrate it try to estimate current position 
using a fake bitrate  of 174.3 kbyte/sec.
elsewere it calc time looking how many byte  it has read and then doing 
byte_read/bps

is possible to make it more accurare reading fps and then doing 
time=framenumber/fps?
if it's possible can somenoe tell me how can i found fps infoo and framenumber 
info , and i'll try to change this.
thanks you