20 Dec
2010
20 Dec
'10
7:24 p.m.
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.