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

[Rudy Zijlstra]

Nick Craig-Wood wrote:

>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.)
>
>  
>
This one has been discussed to death. Search the mailing list.

Short answer: you are mis-using. For the behaviour you want, you need to 
use the start early / end late settings, which actually change the 
scheduler times. The pre- ad post-roll are for a different purpose (like 
getting the backend running in time when using a lan wake-up, allowing 
for long tuner times, things like that).