[mythtv] Using program transitions to synchronise time and hence recording start and end.

[Buzz]

My myth server has it's time set by NTP to a government atomic clock, so
it's accurate.  However ... My recordings on a least one channel, possibly
more are regularly cut-off 2 or 3 minutes early (and start 2-3 minutes
early), so it appears that the station/s time is wrong (or at least
significantly different to mine).

This is irritating.  :-)  I know there are options like "end recording X
minutes late", but having to do this all the time for everything is
irritating too.  I also have been using pre-record and post-record options
(in this case post-record of 300 secs), but that doesn't help in the case of
one recording following immediately after another.


Easy Question 1:  Does DVB (in my case -T) include a stations "current time"
information in the data stream (like in EIT?)  Could this be pulled-out and
periodically logged/analysed so it could be time sync-ed against? (eg like:
Backend time is: 20060311123056, Channel 7 time is: 20060311122844
Difference is: -2:12)

Less Easy Question 2: If (1) isn't possible, what about a stream analyser
that detects program transitions only (like the ad-detector, but a bit
dumber, as it only needs to work for a few minutes around each scheduled
change), and could ensure that the recorder splits the recording/s apart at
the right places.  Bonus is this could also work on analog too, not just
DVB.  For a channel that is "always behind" it's wouldn't need to work
"live" either, it could use earlier program transitions to 

Hard Question 3:  If different channels are telling different times with the
above 1 or 2 methods, how would the scheduler and recorders be made to cope
wit it?  Can the scheduler cope with different time sources for different
channels?   I see this question as likely being a "too hard, no thanks"
question...probably.


Buzz.