[mythtv-users] tuner allocation

[Mark Perkins]

> On 16 Dec 2014, at 5:52 pm, "blind Pete" <0123peter at gmail.com> wrote:
> 
> Hi list, 
> 
> Given three physical tuners that work equally well, with five virtual
> tuners per physical tuner, what is the sanest way to make this work?  
> 
> Edited and re-arranged output from "mythbackend --printsched".  
> 
> 2014-12-16 17:04:52.045637 C  
> mythbackend version: master [v0.28-pre-2438-g206aea9] www.mythtv.org$
> 
> Title - Subtitle           Ch Station Day Start End   S C I T  N Pri
> 
> ABC News                   21 ABC1    16 19:00-19:30  1 1 1 A  1 -10
> 7.30                       21 ABC1    16 19:30-20:00  1 7 7 D  7 -11
> Family Confidential        21 ABC1    16 20:00-20:31  1 6 6 A  6 -6
> Inside Amy Schumer         22 ABC2 /  16 22:29-22:53  1 1 1 A  1 -8
> 7.30                       24 ABC New 16 23:30-00:00  1 0 0 D  E -11
> 
> Mythbusters                73 7mate   16 19:34-20:41  11515 A 15 -10
> Family Guy                 73 7mate   16 20:41-21:10  1 2 2 A  2 -9
> American Dad               73 7mate   16 21:10-21:39  1 1 1 A  1 -8
> Family Guy                 73 7mate   16 21:39-22:38  1 7 7 A  7 -9
> American Dad               73 7mate   16 22:38-23:34  1 6 6 A  6 -8
> 
> Secrets Of Britain         30 SBS HD  16 19:30-20:30  1 0 0 A  L -6
> Secrets Of Britain         33 SBS 3   16 19:30-20:30  1 1 1 A  1 -6
> 
> David Attenborough's Africa 1 ONE     16 20:30-21:33  1 0 0 A  L -9
> 
> Clearly one tuner could handle the ABC (20, 22 & 24 are all on the
> same multiplex), the second 7mate, and the third SBS then ONE, 
> but that is not what happens.  The ABC swaps tuners at 19:30.  
> 7mate swaps tuners at 20:41 and again at 21:39.  One misses out, 
> despite a tuner being free.  (Well 7mate is using two tuners, but 
> apart from that there is a spare tuner from 20:30 to 21:33.) 
> 
> Does anyone want to talk algorithms?  Allocating tuners on a 
> round robin basis rather than from an ordered list might 
> reduce, but not solve the problem.  But the user can not do 
> that anyway.  
> 
> I had a crude mechanism for allocating tuners to multiplexes, 
> but I have deleted it.  I know which multiplex is my favorite, 
> but I am uncertain about my second favorite.  
> 
> -- 
> testing
> bP
> _______________________________________________

Mine routinely behaved like this as well, however when I reported it on this list I was told my configuration was broken. I do not believe my configuration is broken but I got no traction progressing it on this list. However see http://www.gossamer-threads.com/lists/mythtv/users/575314?do=post_view_threaded#575314 and http://www.gossamer-threads.com/lists/mythtv/users/575318?do=post_view_threaded#575318 for what to check.

My final solution was to purchase more tuners. I now have one tuner for each possible multiplex plus one additional for LiveTV (which acts as the emergency tuner for when one multiplex blocks two physical tuners). In theory you could get two multiplex blocking 4 tuners or one multiplex blocking three tuners but for my recording patterns that has never happened (that I have noticed at least) so one emergency tuner is fine.

My interim solution before that was to prioritise my most commonly recorded multiplex to last tuner, second most recorded multiplex to second last tuner, and so on until the remaining multiplex's 'fight-it-out' for the first tuner (first-in-best-dressed).  This improves the situation but does not get rid of it entirely (I don't recall the exact figures but fixed maybe 75% for me, it will depend entirely on your recording patterns). I believe this is the solution most commonly chosen by others with the same problem.

You can see which multiplex you record mostly from on one of the status pages (don't quite recall where, might be in mythweb?).
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mythtv.org/pipermail/mythtv-users/attachments/20141216/a738861d/attachment.html>