IPB

Welcome Guest ( Log In | Register )

Way to quantify degree of loudness-war impacts? (not loudness itself)
Porcus
post Jul 21 2012, 15:52
Post #1





Group: Members
Posts: 1789
Joined: 30-November 06
Member No.: 38207



I am not asking for a utility that computes some average loudness measure (like ReplayGain). (Edit: Argh, thought I was clever to avoid the quotation marks " and ', in order to keep the board from cropping the subject. Forgot about the slash.)


Rather, I am asking whether there have been developed reasonably good measurements -- and utilities implementing such -- for scanning for “loudness war victims”. E.g., criteria like
- dispersion of amplitude (e.g. standard deviation), over some (moving?) average
- distribution of signals near the digital 1.0000 to identify brickwalling (hard or not-very-soft limiting)
- every track on an album boosted to about the same maximum


Of course it will vary over musical genres, but a model that could scan a batch of subjectively “similar” music and with a reasonable accuracy (i.e. sensitivity/specificity) detect those “bad remasters”, would be a good start.


Anything? Anyone?

This post has been edited by Porcus: Jul 21 2012, 15:57


--------------------
One day in the Year of the Fox came a time remembered well
Go to the top of the page
+Quote Post
 
Start new topic
Replies
Woodinville
post Aug 15 2012, 21:37
Post #2





Group: Members
Posts: 1402
Joined: 9-January 05
From: JJ's office.
Member No.: 18957



clear all
close all
clc

fname='12.wav'
x=wavread(fname);
x=round(x*32768);

len=length(x)

his=histc(x(:,1),-32768:32767); % channel 1
his=his+histc(x(:,2),-32768:32767); %channel 2

tot=sum(his);
his=his/tot;
his=max(his, .000000000001);
xax=-32768:32767;

semilogy(xax,his);
axis([-40000 40000 1e-10 1e-1]);
big=max(max(x))
small=min(min(x))

fname

In octave will give you a nice histogram of the actual amplitudes in a 16 bit digital file.

You can find some frightening results at: http://s238.photobucket.com/albums/ff228/j...l%20Histograms/



--------------------
-----
J. D. (jj) Johnston
Go to the top of the page
+Quote Post

Posts in this topic


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 23rd April 2014 - 20:11