[MPlayer-dev-eng] how does vd_mpegpes.c::decode() decode the *.m4v bs

[boku]

Dear all,
     I have a mpeg2 movie *.m4v and trace the mplayer's decode process. I
found it uses vd_mpegpes.c to decode the bs. However,
I checked the ::decode() and don't know where or which function is the main
decode process to do the decoding.
Isn't the vd_mpegpes just the wrapper to connect with internal actual
decoder?
Thanks!~