Re: [LAU] Gain and clipping wav -> lame

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)
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