[mythtv-users] EIT/EPG, "Not Listed" status and approximate string matching

[Michael T. Dean]

  On 10/25/2010 08:28 AM, Prakash Sabapathy wrote:
> Apologies if this has already been covered previously.
>
> My combined frontend/backend (HTPC) is configured to extract EIT/EPG 
> data via DVB (Melbourne, Australia). Myth generally has nine days 
> worth of EPG available. Recordings are typically scheduled using EPG 
> data (via the program guide) and in most instances the HTPC records 
> shows without error. However in some instances the show is not 
> recorded due a subtle change in EPG; e.g. title. Typically under 
> recording is shown with the "Not Listed" status under "Upcoming 
> Recordings".
>
> To circumvent this issue, is it possible to configure Myth to record a 
> show based on EPG data known at the time when the show was to record? 
> i.e. effectively disregard future changes in EIT/EPG data and 
> therefore allow the recording to occur without needing user 
> intervention in the event of a show becoming "Not Listed" due to 
> subtle change in EIT/EPG data. Clearly this option will be in addition 
> to the options already available: "Record Only This Showing", "Find 
> and record one showing of this title" etc.
>
> Effectively, when the user requests for a show to be recorded with 
> this option, Myth automatically creates a manual record rule or 
> similar and populates it with the known EIT/EPG data with regards to 
> title, start and end time etc.
>
> Failing that, is it possible to perform some type of fuzzy string 
> matching logic to allow a recording to proceed even when changes are 
> made to the EPG? e.g. revised EIT/EPG data is within 95% of previous 
> data and therefore proceed with recording.

The preferred approach--especially if it's the /title/ that's 
changing--would be to create a custom Power Recording rule, rather than 
change scheduling to allow fuzzy-string matching of titles.  All of 
MythTV is structured around the titles of a show staying constant, so 
such a change would be huge--and likely have a lot of consequences even 
for people who have good listings data.

To create a Power Recording rule, you can start with the "Match words in 
the title" example clause.  Or, better, if you have a series ID, you can 
use "Match this series" or, if you have a program ID, "Match this 
episode".  (Note, though, if your series ID and program ID are generated 
by MythTV, they will be generated based on title, so won't help.)  Or, 
depending on the data itself (and what stays constant), you may be able 
to come up with a much better rule--you're only really limited by your 
creativity.  A fallback is always available, too--use a manual recording 
rule.

Depending on what's happening to the title, you may be able to fix it 
with an EIT fixup.  If, for example, the title changes from "The Event" 
to "The Event - Season 1" or similar (i.e. just adding some additional 
non-title information to the title), you could create a fixup that fixes 
the title breakage.  See mythtv/libs/libmythtv/eitfixup.cpp and 
mythtv/libs/libmythtv/eithelper.cpp , and you can find changesets that 
add new fixups (like http://svn.mythtv.org/trac/changeset/26355 ) to use 
as examples.

Mike