[MEncoder-users] VHS capture: poor framerate

[newsgrabber at poczta.onet.pl]

the system is MDK 10.0, MEncoder 1.0pre6-3.3.2, hardware: FlyVideo 98 (bt878), 
Celeron 2.4 GHz. 

I've seen in the archives that this question was asked before, but found no 
answer. 

What is the reason for very low framerate while capturing some VHS tapes. I 
have, for instance, some tapes, recorded on my own 4 head VCR, some recorded 
by my friends and some original movies purchased in a shop. Now, some of them 
make mencoder stay at 25 fps (the system is PAL) and record very well, while 
some other cause the framerate to drop to 18 or even 11 - 12 fps just a few 
seconds after capturing starts - and the resulting material is of very poor 
quality. 

I can find absolutely no relation between, say, the picture quality on the 
tape, or the VCR used for recording/playing-for-capture and the resulting 
capture fps. I even have some purchased tapes with TV series, out of which 
one tape cannot be captured because of the fps going down to 11 fps while 
others captured very well.

I tried also to connect one of these devices that "clean and multiply the 
signal, removing any copy protection system" but it didn't help either. 



Is there any solution to this?