[mythtv] Closed captioning and commercial detection

[Dan Schwarz]

Grant Taylor writes:

>And one could straightforwardly weed out duplicate episodes without
>being limited by the details in the tv guide data.
>
>CC's might also be another source for commercial boundary information;
>often one or the other isn't captioned.  Although I suspect the
>presence or absence of CC data may not be so clear...
>  
>
These days, many national advertisers are using closed captions, but if 
you pay attention to the style of captions used, it may be possible to 
distinguish captioned commercials from captioned programming. Many 
commercials use the "paint-on" style of captions as opposed to the "roll 
up" or "pop-on" style used in programming. A change in caption style may 
indicate a commercial or a switch from one program to the next.

And of course one could always examine the /content/ of the captions to 
detect commercials.  You could use one of those new "bayesian email spam 
filtering" algorithms to detect commercials :-)  

For more detailed information on closed captioning technology, check out 
this site:

http://www.robson.org/gary/writing/nv-line21.html

Regards,

Dan Schwarz