[mythtv-users] Re: Automatic Commercial Detection - how to get it

Michael T. Dean mtdean at thirdcontact.com
Wed Sep 22 13:42:13 EDT 2004

On 09/22/2004 10:36 AM, Gavin Hurlbut wrote:

>Chris Pinkham <cpinkham at bc2va.org> wrote:
>>I've yet to look at the audio data enough to know this or not, but I've heard
>>and read that it's not volume, it's something else that changes that makes
>>it seem louder.
>I think that the commercials are more compressed (using dynamic compression,
>not like MP3 compression), so they appear louder to the human ear.  Also, they
>may also be boosting the levels after the compression.
Yeah.  That seems to be the most common cause for the apparent 
difference.  Fortunately, enough consumers have been so upset by the 
apparent increase in volume that a lot of tax-payer dollars around the 
world have been spent to figure out what's going on...

Here are some links:

Best technical description:  
Nice article describing a gadget that "corrects" audio level - gives 
some good things to think about: 
Slightly technical, pretty humorous: 
 From Canada: http://www.crtc.gc.ca/eng/INFO_SHT/G3.HTM
 From Australia: 
 From the US: http://www.fcc.gov/cgb/consumerfacts/backgroundnoise.html


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