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From: jnp@calmasd.GE.COM (John Pantone)
Newsgroups: sci.electronics,rec.video
Subject: Re: VCR comercial eliminator
Message-ID: <45@calmasd.GE.COM>
Date: 31 Aug 88 16:38:21 GMT
References: <257@ivucsb.UUCP> <16314@apple.Apple.COM> <17659@glacier.STANFORD.EDU> <1831@loral.UUCP>
Organization: GE/Calma, 9805 Scranton Rd., San Diego, CA 92121
Lines: 38
In-reply-to: jlh@loral.UUCP's message of 30 Aug 88 15:48:20 GMT


>I don't know why everyone is discussing fade to black detection, special
>signals in the vertical sync, or whatever for commercial detection.  All
>ya gotta do is monitor the sound track and wait for the volume to go up.

Because the "fact" that TV commercials are louder than the program
material is simply a myth.  The FCC was involved in an investigation
recently (several years ago, I think), and the results were negative;
commercials vary their sound levels roughly identically to program
material. They do, though, frequently use various compression and/or
expansion schemes to cause a higher "modulation percentage" in the
soundtrack, and to prevent "dead-air" (silence is anathema to
advertisers).

There is no signal present on broadcast tv which presages a commercial
- if there was that network would find itself bankrupt awfully fast -
can you imagine spending hundreds of millions of dollars advertising
on a tv station whose viewers could effectively ignore your
commercials?

I can't comment on cable - although I should imagine that the
commercial forces would be the same there.

Fade-to-black is a fairly good way to detect a commercial - except of
course when it occurs during the program - probably not frequently in
comedies, but dramas use this technique frequently; yielding a 30
second hole in your recording.

I'm afraid that there just isn't a very good way to avoid commercials
- in an automated system; and if one is found, the advertisers and tv
broadcasters will surely institute lawsuits and/or countermeasures -
advertising is their paycheck.


-- 
These opinions are solely mine and in no way reflect those of my employer.  
John M. Pantone @ GE/Calma R&D, 9805 Scranton Rd., San Diego, CA 92121
...{ucbvax|decvax}!sdcsvax!calmasd!jnp   jnp@calmasd.GE.COM   GEnie: J.PANTONE