lavc=9000 and bitrate

Hi,
i am testing with a small piece of divx coded recording (1 min). I am 
wondering about the size of the dumped mpeg-pes.
I had recorded this piece from my dvb-card with vdr and converted to divx with 
mencoder. I could play the divx-file on my desktop with no problems. But if i 
play this video on the dvb-output without lavc=9000 i got stuttering video 
and audio. So i dumped the stream to a file (mplayer -vo 
mpegpes:testfile.mpg) and look what i get.
Unfortuanally i can't check the dumped file with Projekt-X(ds.jar). X805 
crashes at loading time.....
Any helps about the format of testfile.mpg???
And now: the size of the testfile,mpg suggested a bitrate of 18400kBits/s, 
dumped again with lavc=9000 i got a file related to a bitrate of 8700kBits.
>From where comes the high bitrate ? My Input (at vdr time) has only ~ 
3500kBits/sec.

Because i want to archieve my recording i will check if the divx generation is 
ok and can played back without problems.

Any Ideas ?

Regards, Alfredo