[mythtv-users] Can I stop the truncation of pre-roll/post-roll

[Nick Craig-Wood]

Is it possible to stop the truncation of pre-roll/post-roll?

I'm not sure what this feature is called in mythtv, but in order to
optimise the number of recordings mythtv will truncate the pre-roll /
post-roll of a show in order to switch to another show which starts at
the same time the first finishes.

Here are some concrete examples from my recorded shows.  Normally I
have start early / pre-roll set to 240 seconds and post-roll set to
420 seconds (though I only get 300s for some reason).

mysql> select chanid,progstart,progend,UNIX_TIMESTAMP(progstart)-UNIX_TIMESTAMP(starttime) as pre_roll,UNIX_TIMESTAMP(endtime)-UNIX_TIMESTAMP(progend) as post_roll,title from recorded order by starttime;

+--------+---------------------+---------------------+----------+-----------+------------------------------------+
| chanid | progstart           | progend             | pre_roll | post_roll | title                              |
+--------+---------------------+---------------------+----------+-----------+------------------------------------+
[snip]
|   2501 | 2006-02-24 18:00:00 | 2006-02-24 18:30:00 |      240 |       300 | BBC News and Weather               |
|   2509 | 2006-02-24 21:30:00 | 2006-02-24 22:00:00 |      240 |         0 | The IT Crowd                       |
|   2510 | 2006-02-24 22:00:00 | 2006-02-25 00:25:00 |      240 |       300 | Stepmom                            |
|   2509 | 2006-02-24 22:00:00 | 2006-02-24 22:35:00 |        0 |       300 | My Name Is Earl                    |
|   2501 | 2006-02-24 23:05:00 | 2006-02-25 00:45:00 |      240 |       300 | Twins                              |
[snip]
|   2501 | 2006-02-27 18:00:00 | 2006-02-27 18:30:00 |      240 |       300 | BBC News and Weather               |
|   2502 | 2006-02-27 20:30:00 | 2006-02-27 21:00:00 |      240 |         0 | University Challenge               |
|   2501 | 2006-02-27 21:00:00 | 2006-02-27 22:00:00 |        0 |       300 | Life on Mars                       |
|   2507 | 2006-02-27 22:00:00 | 2006-02-28 00:20:00 |      240 |       300 | The Silence of the Lambs           |
+--------+---------------------+---------------------+----------+-----------+------------------------------------+

So most of the shows have the correct pre- and post-roll.  However
"The IT Crowd" on 2509 ended at the same time as "My Name Is Earl" on
2509 so mythtv cut straight from one to the other.  In this case the
pre- / post- rolls will be there just in a different recording.

However "University Challenge" on 2502 cut straight to "Life on Mars"
on 2501 on a different channel so pre-/post-rolls are truncated there
and hence potential the start / end of the shows.

I'm finding this behaviour quite annoying.  Because the broadcaster
doesn't schedule the shows accurately it means I'm often missing the
start or end of shows.

Is it possible to disable this behaviour?

I'm finding this behaviour more irritating now because I've got a lot
of low-priority stuff which I don't care if it gets recorded or not.
Mythtv then juggles the schedules around to record an extra low
priority show and in the process snips the end off my favourite show.
This would still happen even if I had more tuners, though more tuners
would obviously help.  (I've got two.)

-- 
Nick Craig-Wood <nick at craig-wood.com> -- http://www.craig-wood.com/nick