🚀 go-pugleaf

In article <1992Sep03.042045.5095@ecst.csuchico.edu>, rmintz@ecst.csuchico.edu (Rich Mintz) writes:
> I'm interested in building a device (or making my 386sx 
> act like one) that will be able to distinguish television 
> commercials from television programs. I've talked to a 
> few people and have heard of a couple of ways it is said 
> that this can be done.
>  
> First, I was told that the audio during commercial 
> announcements on tv is boosted higher than that used for 
> normal programs (for obvious reasons). However, I've 
> tried all kinds of analysis with volume levels, averages 
> over specific periods of time, etc, using my computer's 
> sound card (with stereo capability), with no luck at 
> finding any dependable pattern to distinguish    ads from 
> shows.
>  
> Someone else told me they had heard that what I'm wanting 
> can be acomplished by analyzing the video transmission 
> for the presence of computer-encoded information that 
> accompanies programs, but not commercials. I assume he 
> was referring to Closed-Captioned (CC) text sent along 
> with many shows for the benefit of the deaf who have 
> special receivers for these signals.
>  
> Any suggestions? Thanks.
>  
>    Rich -> rmintz@cscihp.ecst.csuchico.edu
> 

You are going to have real problems.  First of all, some commercials come from
the networks, some from the local stations, and some from syndicators, already
in the program.  The audio in the commercials is held a little low, at least by
the networks, to keep the FCC from being deluged by "loud commercial"
complaints.  Most local stations process their audio (AGC) fairly hard, so
everything comes out pretty much the same level.  Many commercials are
closed-captioned these days.  There used to be a box (or at least plans for
one, perhaps in Radio-Electronics), which sensed the momentary switch to black
which accompanied most commercials (they usually are inserted after the program
is already taped, so there often is a moment of black before them) and switched
the signal off for 30 or 60 seconds, but now with commercials of 10, 15, 20, 30 
60, etc seconds, and 5 second teases, there would be no way to know when to
come back, and there are a lot of moments of black between scenes, news
stories, etc.  

If there was a way to do this, it would be a big seller at electronics stores,
believe me!!

John

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