[LAD] peak has nothing to do with loudness (check out EBU R128)

Philipp Überbacher hollunder at lavabit.com
Tue Dec 21 00:10:27 UTC 2010

Excerpts from Jörn Nettingsmeier's message of 2010-12-20 19:27:28 +0100:
> On 12/20/2010 03:49 PM, Paul Davis wrote:
> >> The documentation of the natural drum sample library is quite good. The only
> >> thing missing is the "loudness" of each sample in order to map each sample
> >> to a velocity level from 0-127.
> >>
> >> What would you  recommend in order to calculate the "peek" of each drum
> >> sample automatically? Is there a library which could do this? I would also
> >> be happy with a command line tool like this:
> >
> > sndfile-info /music/misc/onewayjam_organ.ogg
> <...>
> > Signal Max  : 0.805912 (-92.18 dB)    <<<<<<<<< HEADS UP!
> > 
> > Works for any audio fle that libsndfile can read, which is just about anything.
> > 
> > there is a complication: loudness is no identical to maximum sample
> > value, but the relationship is good enough for government work, so to
> > speak.
> no, it's not. there is absolutely no meaningful relation whatsoever
> between perceived loudness and peak value. that's why the EBU is (after
> all those years) moving to k-weighted loudness as a metering standard
> rather than QPPM. true, peak measurement used to be the norm, but it was
> never good for anything (not even government work) except to avoid
> clipping downstream.
> florian camerer of orf presented a very enlightening talk at the
> tonmeistertagung in leipzig this year, which i had meant to post earlier
> but forgot. thanks for this reminder :)
> http://tech.ebu.ch/docs/techreview/trev_2010-Q3_loudness_Camerer.pdf
> it starts a bit boastful, but rightfully so, since it's in effect _the_
> peace treaty to end the loudness war.
> bottom line: those who have been using bob katz' k-system (for example
> as implemented by fons adriaensen in jkmeter) don't have to change much...
> but if you're interacting with radio stations regularly, you might want
> to implement the EBU R128 standard, whose loudness measuring method is
> slightly different.

Wow, amazing that someone from ORF manage to write something useful. I
thought ORF doesn't employ anything but a board of directors and freelancers,
so whenever something goes wrong they can blame it on contractors.
I'm really very surprised that there's someone inside this beast who
actually does something.

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