[mythtv-commits] Ticket #12308: Improve mythcommflag accuracy

[MythTV]

#12308: Improve mythcommflag accuracy
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 Reporter:  faginbagin <mythtv@…>  |          Owner:  cpinkham
     Type:  Patch - Bug Fix        |         Status:  new
 Priority:  minor                  |      Milestone:  unknown
Component:  MythTV - Mythcommflag  |        Version:  0.27.4
 Severity:  medium                 |     Resolution:
 Keywords:                         |  Ticket locked:  0
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Comment (by jpoet):

 In my testing, these patches improve the detection for most channels.
 However, on some channels I have shows which went from good detection (9
 of 12) to terrible (3 of 12). I would feel much better about committing
 these patches if they were at least no-worse than the detection without
 them.

 It may be impossible to achieve an automatic set of parameters for all
 channels. The solution may be to make some of these changes user-tunable,
 with profiles which could be saved, and then selected on a channel by
 channel basis, or a recording by recording basis. My knowledge of the
 commflag code is not in-depth enough to know what parameters would need to
 be tunable, however.

 faginbagin mentioned to me that setting the percentage of matching frames
 during the logo detection could be a prime target for a tunable. There are
 likely other parameters which would need to be tweaked differently from
 some channels (shows) compared to others.

 I will play with the logo detection parameters and see if I can 'fix' the
 detection of the show which dropped from a 9 of 12 accuracy to a 3 of 12.

 In the US (at least), adding detecting for the "TV Parental Guidelines"
 logo would greatly help in the detection coming out-of-commercial. From
 the Wikipedia article:

 > For the first 15 seconds of every rated program lasting a half-hour or
 less, a large rating icon appears in the upper-left hand corner of the
 screen. The icon was much smaller until June 2005 and only appeared on-
 screen for 7.5 seconds. For every rated program running an hour or longer,
 a rating appears in the upper-left hand corner of the television screen at
 the beginning of each half hour. Starting in June 2005, many networks now
 display the ratings after every commercial break, in addition to the
 beginning of the program. If a network uses a 16:9 format for its
 presentation, generally all rating icons appear in the 4:3 safe area of
 the feed.

 The commflag code does not currently find or use that logo.  Personally, I
 don't mind so much when the detector misses the change from show to
 commercial, but I would like it to nail the transition from commercial to
 shoe.  Using the "TV Parental Guidelines" logo should make that possible,
 I would think, for most shows -- at least in the US.

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Ticket URL: <https://code.mythtv.org/trac/ticket/12308#comment:11>
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