[mythtv] help needed to complete opaque logo commercial flagging.

Chris Pinkham cpinkham at bc2va.org
Thu Dec 2 18:13:32 UTC 2004


> Hi Chris,
> 
> I already tried to use nvp->JumpToFrame(0) and nvp->ClearAfterSeek(), but 
> to no avail. Recently some changes were applied by you to change 
> framesPlayed to framesRead. maybe I was also looking at the wrong value. 
> However, the frames fetched using nvp->GetLastDecodedFrame() did contain 
> the frame corresponding to framesPlayed.

At the end of your new method, you have "nvp->JumpToFrame(seekIncrement);",
is that why you're not being reset to the beginning of the video after
you do your logo detection, or do you mean it's ending up somewhere else?

> If I understood the commercial detection code in CVS correctly, it was 
> designed to detect semi-transparant logo's. (at least, the code contained a 
> lot of edge detections). My code is only about non-transparant logo's. They 
> are a bit easier to detect (but still I needed about 100 frames spread over 
> 30 minutes of recording)
> 
> thanks that you want to have a look at it. If you need additional 
> explanation, please feel free to contact me.

If one algorithm works better for transparent and one better for opaque then
end the end we can run both and check to see whether the show has a transparent
or opaque logo and use whichever is found.  That will be better than making
the user choose a type.  I'd like to eventually get to the place where all
detection methods can be used.  I'm seeing more and more places where stations
are putting their logo on the blank/black frames between shows and commercials
and that is really messing up commercial detection.  CBS seems to be doing a
lot of this lately on the shows my wife and I watch.  That's why I've been
looking at logo detection more recently so I can detect those places where
they display the logo in the frames between commercials and show (possibly
to fool software/hardware that uses blank/black frame detection to detect
commercials).

I'll look forward to trying this out once you get it "finalized". :)
-- 

Chris



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