[LAU] Gain and clipping wav -> lame

[Fons Adriaensen]

On Fri, Jul 26, 2013 at 06:35:02PM -0400, Martin Cracauer wrote:

> ebur128 --lufs:
> Integrated loudness:     -4.9 LUFS
> Loudness range:           5.5 LU
> Integrated threshold:   -13.0 LUFS
> Range threshold:        -25.0 LUFS
> Range min:               -8.6 LUFS
> Range max:               -3.1 LUFS
> Momentary max:           -1.2 LUFS
> Short term max:          -2.4 LUFS

This seems to be in the 'braindead' category...

> I don't see that any of the value correspond with what lame needed to
> not clip over a collection of different loudness clips.  (means: some
> clips that needed less --scale have higher numbers here and others
> have lower)

You can't expect that. Lame's limit are specific for the algorithm
it uses. That would be the case for any lossy encoding system. 

> I assume the ebumeter output is more for making things sound even
> (between different pieces) and not directly a tool to max out
> anything, is that right?

That is absolutely right. Systems such as EBU-R128 exist because
it makes perfect sense to make things sound even (avoiding your
listeners having to adjust the volume all the time), while 'maxing
out' serves no useful purpose at all - it just destroys the sound
if taken too far. In other words, such systems exist to *stop* you
'maxing out' everything.

Lame's 'replaygain' meausurement has the same purpose. Note the
value for the file in your original post: -9.1 dB. That means
that an intelligent mp3 player will *reduce* the level of this
file by 9.1 dB when playing it - it is already much too loud.

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)