Newspage on "Version 1.00 RC1 Build 809 released (16 Jun 2004)" mentions:
"filters defined in bspfilters.dat will now be loaded even if other libraries are required (for ex. xvid.ax require xvidcore.dll), just put them all in .\filters directory"
Perhaps you could use
HWmaker (info here). (you can
download it here).
Using "Search button" i.a. results in these posts (did you already see them)?
http://forum.bsplayer.org/viewtopic.php?p=11068#11068 http://forum.bsplayer.org/viewtopic.php?p=14302#14302
(Many further posts)