[mythtv] vps/pdc almost there...

[maestro]

hi all,

i hope not to bother anyone with my continuous talking about vps/pdc.

a quick status of my proceedings shows, that i'm now capable of
receiving the vps signal and delay the start/end of a recording until
the vps matches. so far so good. 

BUT today i encountered a constelation which i did't take into account
so far, mainly because i cannot think of a solution to what seems to be
a trivial problem:

stop recording would best be determined if the vps signal is different
then the one that kicked the recoding off, right?!

so how to determine when to start a recording.
it works fine if starttime (from epg) matches vps timecode exactly, but
i scheduled C.S.I. Miami today which was scheduled for 22:50 in the epg
but when the show was broadcasted the vps timecode was 22:55 so a simple
comparrison does not always work. (result the show wasn't recorded at
all => very bad)

can anybody help me solving this comparrison problem, or even better is
anyone familiar how vps is handled in plain old vhs recorders?

hoping for some answer,
so long
maestro