[mythtv] Proposed alternate behaviour for show delete

William Uther willu.mailingLists at cse.unsw.edu.au
Wed Mar 9 21:42:18 UTC 2005

Hi all,

Brad wrote:

> I would roughly sort the expire pools as follows:
>     a) Never-expire shows       = 0
>     b) Unwatched shows          = 100
>     c) Watched shows            = 200
>     d) "suggestions" (possibly more than one pool)  = 300
>     e) Shows manually cleared for removal   +1000 to earlier number
> Within each pool, one sorts by date, however there are some alternate
> internal sorts which might make sense.   For example, explicit solo
> recordings and non-rerun episodes might stand ahead of reruns and
> find-all recordings.   Ie. if you explicitly asked for something, 
> protect
> it more.

If there is a strict sort order (sort by 'autoexpire' first, then by 
date), then there is no difference between this and

>     a) Never-expire shows       = 0
>     b) Unwatched shows          = 1
>     c) Watched shows            = 2
>     d) "suggestions" (possibly more than one pool)  = 3
>     e) Shows manually cleared for removal   = 4


The different numbers would only have an effect if they were being 
combined with something else...

Isaac wrote:

> I think the various existing options work for most purposes (oldest 
> first,
> show limit, do/don't record new if there's a show limit, disabled for a
> recording id, etc).  Using the original recording priority would be a 
> decent
> extension, as would based on if it were watched or not.
> I still don't see the point for an undelete function if autoexpire's
> explicitly turned on.

I tend to agree with Isaac.  But note that there are two parts to his 

a) The undelete may not be so useful, given that you can...
b) Improve the autoexpire so that it gets things right.

I read this as just a call to get b) right.

I use the show limit function to actually limit the number of 
recordings (I only ever want one recording of the daily news).  I also 
use it as a rough 'autoexpire' tuner. (We get 3 Simpsons episodes a 
day.  I don't want a tide of Simpsons episodes causing all my other 
shows to auto-expire, so I set a show limit on it.)

I really like Isaac's idea of using the original show priority.

I wonder if a linear combination might work here.  When deleting, shows 
are ordered by:

delete priority = weightA * time since recorded - weight2 * record 
priority + weight3 * watched_flag

The highest 'delete priority' show is deleted.

This way I can have watched shows being deleted first, then a trade off 
between shows of high record priority that I haven't watched in two 
weeks and lower record priority shows that are being recorded today.

I'm sure that the formula above could be tuned, but I thought I'd 
mention the concept.


Will        :-}

Dr William Uther                           National ICT Australia
Phone: +61 2 9385 6357               Computer Science and Engineering
Email: willu at cse.unsw.edu.au          University of New South Wales
Web: http://www.cse.unsw.edu.au/~willu/     Sydney, Australia

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