[mythtv-users] scheduling not using all three tuners?

Peter Schachte schachte at csse.unimelb.edu.au
Tue Apr 11 13:38:02 UTC 2006


On Tue, Apr 11, 2006 at 05:24:10PM +1000, Max Barry wrote:
> people ... were using the soft buffers to try to catch parts of TV
> shows that weren't broadcast within schedule.

I live in Oz too, and have had severe WAF and KAF problems due to
missed program endings, so this is a subject near and dear to my
heart.  On reflection, I'm not sure this fix is the right one.
[Actually, the right fix is to hit the Aussie TV stations upside the
head until they understand what a schedule is, but failing that....]

The current pre-roll and post-roll are, I understand, intended to
allow tuner cards to get ready to record.  Perhaps you're recording
from a satelite tuner and need time to point the dish at the right
satelite before starting to record.  Or maybe your tuner card needs a
few extra seconds to tune the right channel.  In either case, you
don't want to actually *record* early, you just need to start the
tuning process early.  But the need here is not universal; if you have
a satelite tuner and digital a cable tuner, and an analog terrestrial
tuner, they each need a different pre-roll time.  So I would expect
this pre-roll would be set per input.  Furthermore, by this
understanding, pre-roll would not be needed for the second of two
recordings in a row on the same channel on the same input, but would
be needed for different channels on the same input.  (I can't for the
life of me work out what the post-roll is for, so maybe I've missed
something.)

But this is all very different from needing to cope with television
stations that can't (or choose not to) keep on schedule.  For that,
you certainly do need to record early and late.  Of course, you can
(and I do) compensate for this using the "start early" and "end late"
recording feature, but that's a bit of a nuissance to do for every
recording scheduled.  It would be nicer to be able set that up once.
Here in Australia, the public stations tend to run pretty much on
time, whereas you really need to end 10 minutes late if you want to
record something on channel 10, so different *channels* need different
start early and end late values, regardless of input or *program*.
And when recording consecutive programs on the same channel on the
same tuner, it's probably OK to ignore the start early and end late
values, but it would be better to record the broadcast for the
overlapping time as part of *both* programs (there was some discussion
here of doing that; that would be very useful).  Currently I schedule
most programs on the commercial stations to end 5-10 minutes late, and
then manually override consecutive recordings on the same station to
get rid of the second one's start early and first one's end late so
they can be scheduled on the same tuner.

So it seems to me the right thing is to have a pre-roll (and
post-roll?) per *input*, and default start early and end late values
per *channel*.  And when consecutive programs are to be recorded on
the same channel and the same tuner, the pre- and post-roll can be
ignored, and the start early and end late values shouldn't prevent
consecutive programs from being recorded on the same tuner (though
ideally the overlapping end late/start early time would be included in
both recordings).

-- 
Peter Schachte              A paranoid is just someone with all of the facts
schachte at cs.mu.OZ.AU        at his disposal.
www.cs.mu.oz.au/~schachte/      -- William Seaward Burroughs 
Phone: +61 3 8344 1338      


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