[mythtv-users] Show showing as already recorded when it is not.

[Michael T. Dean]

On 09/04/2014 08:31 AM, stinga wrote:
> On 04/09/14 11:08, John Pilkington wrote:
>> On 04/09/14 10:51, Simon Hobson wrote:
>>> stinga wrote:
>>>
>>>> programid for an old show matches, I seem to remember this issue 
>>>> from before.
>>>>
>>>> Terror of the Autons is series 8 episode 2 from 1971
>>>
>>> Nice when they do that isn't it ?
>>>
>>> Going from a very vague memory having done it once or twice "some 
>>> time" ago ...
>>> On a frontend, go to "Previously Recorded" where you'll find a list 
>>> of everything that's ever been recorded (and not deleted with the 
>>> "Delete and Re-record" option) - it'll be a long list !
>>> Scroll down to the episode in question.
>> Takes forever.  If you have a keyboard ctrl/s lets you search.
>>> If you press Enter rather than Menu, you will get various options - 
>>> one of which is to forget all previously recorded episodes which is 
>>> useful when you get a "new" show that repeats the series no etc from 
>>> the "old" shows.
>>>
> There has got to be a better way, I might hack /myth/bin/tv_grab_uk_rt 
> to remove episode data if Doctor Who, would not be hard.
> programid=EP19090030328 is a concat of 
> EP<elfhash(title)><episode><series> so now I know where that comes from.
>
> Why can't we have programid in the 'Duplicate Check method' by default 
> and then all the other options, so that we can override the programid 
> when we know it is bad.

Because progamID is, by definition, the definitive identifier of a 
program, it is always correct and no user would ever want to ignore it.

The problem here is that the XMLTV-reading code is faking a program ID 
if none is provided, under the (false) assumption that no two series 
will ever have identical titles (or the optimistic assumption that users 
will be willing to delete recording history of the older series when 
recording the newer or vice versa).

The proper fix isn't to change MythTV to allow optional use of program 
ID, but to quit faking program IDs in the mythfilldatabase XMLTV code.  
That change has been discussed (and, TTBOMK, all affected developers 
agreed it may be better than the current approach), and you may well be 
able to get a patch accepted that removes the program-id-generation code 
without much time or effort or politicking involved.  It would involve 
removing the appropriate portions from the block at:

https://code.mythtv.org/cgit/mythtv/tree/mythtv/programs/mythfilldatabase/xmltvparser.cpp#n541

(and not the code at line 444, which is correct).

Note, though, that some users will be upset that they start getting 
re-recordings of shows they previously recorded due to slight changes in 
episode (sub)title and/or description since the time they first recorded 
the episode, which would mean those users would have to manually verify 
their recording schedule and "don't record" episodes they know are 
repeats or just record and delete repeats.  But it all comes down to the 
listings: garbage in = garbage out.  (And I'll admit that's of little 
comfort to those whose listings aren't high quality.)

If you want to appease those users, you would need to add a new 
duplicate check method that uses title + season + episode (not 
programid, not seriesid, not syndicatedepisodenumber).

Mike