[mythtv-users] Obama Recommends Delay in Digital TV Switch
David Brodbeck
gull at gull.us
Mon Jan 12 00:25:48 UTC 2009
Drew Tomlinson wrote:
> OK, I have to ask. Now while I agree that sending "all the signal to
> the rich neighborhoods" is silly, there certainly appears to be
> occasions when commercials are much louder than the programming.
My guess is the peak level is no higher, but that they're compressing
the dynamic range so that more of the audio is at peak loudness. This
is perceived as louder and "punchier" than uncompressed audio, because
our idea of how loud something is is related to the average level more
than the peak level. Also, if you're watching a movie, movie
soundtracks often have dialog and such at a fairly low level so that
they have room to go louder for things like explosions.
Sometimes commercials also use Dolby Pro Logic encoding to send audio to
the back channel speakers, if you have surround sound.
Now, in the case of locally-inserted commercials on cable TV systems,
there may actually be a difference in peak level. I've noticed that
most cable TV systems do a really incompetent job equalizing the volume
levels between channels and between locally-inserted content and network
content.
More information about the mythtv-users
mailing list