[mythtv] [mythtv-commits] Ticket #8522: Include only half the blank frames between commercial breaks

[Jim Stichnoth]

On Sun, Sep 12, 2010 at 6:36 PM, Chris Pinkham <cpinkham at bc2va.org> wrote:
> * On Sun Sep 12, 2010 at 09:29:31PM -0400, Michael T. Dean wrote:
>> Yeah, I have no idea what the stats are like--how many frames should be
>> blank and how many get seen as blank (especially in the cases of
>> misdetection).  The idea of using half the frames all the time works for
>> me, as long as we don't just end up using "half a runaway number."
>> Maybe half with a upper bound for a sanity check?
>
> I'm fine with using halfway as well as long as we have some upper boundary,
> even if it's 5 or 10 seconds.
>
> The main reason behind just using a max instead of "1/2" was to make things
> consistent, but I can see the benefit in using 1/2 since there are some
> TV stations that like to fade to black while there is still audio.  Using
> 1/2 in this instance will catch all or most of the show, but using a max of
> say 3 or 5 frames might cut off some of this audio.  Personally I've run
> with the 'skip all blanks' option for a long long time, but I mentioned to
> Michael that I occasionally find myself rewinding to make sure that the
> commercial skip was indeed accurate because the TV station decided to come
> back from commercial in the middle of a scene.  The "1/2" of all blank
> frames would help eliminate second-guessing the flagger in those cases. :)

I'm not sure exactly how the (let's say) 10-second upper bound should
be applied.  Suppose the commflagger analyzes a recording like this:

0:00:00 Start of program segment
0:10:00 End of program segment, start of blank interval
0:11:00 End of blank interval, start of commercial
0:15:00 End of commercial, start of blank interval
0:16:00 End of blank interval, start of program segment
0:30:00 End of program segment

Using the 1/2 blank interval, the commflagger would set a commercial
break from 0:10:30 through 0:15:30.  What is the intention if the
10-second upper bound is applied?  Should the commercial break be set
as 0:10:10 through 0:15:50, or 0:10:50 through 0:15:10?

I'm happy to update the #8522 patch to eliminate the setting and use a
single approach.  But first I'd like another 2-3 weeks to test, since
the Fall TV season is about to hit full-force, and the summer TV
season didn't really allow for adequate testing.

Jim