🚀 go-pugleaf

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