25 Jul
2013
25 Jul
'13
9:40 p.m.
On Thu, Jul 25, 2013 at 02:21:50PM -0400, Martin Cracauer wrote:
Does anybody know why wav files that do not have
clipping would clip
when encoding them with lame?
Because the peak sample value says nothing about the real
level. Take a square wave with peak values +/-1. It is the
sum of a number of sine waves, with frequencies 1,3,5,7,...
times the frequency of the square wave. The first one has
a peak value of about +/-1.27, that is +2 dB. So any encoding
that looks at the spectrum (and mp3 does) will see a level
that is +2 dB.
If you really want to normalise on the peak level, use a
lower one. If you want all your samples to have the same
loudness, use RMS instead of peak, or a real loudness
measurement such as provided by ebumeter.
Ciao,
--
FA
A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)