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Normalizing Music?
Beans asks: "I have a couple classical music CD's which I listen to at work, and use for putting the baby to sleep. I can never find the correct volume, I can't hear soft spots, so I turn it up, only to have a rising crescendo rouse the baby, or at work, have co-workers glace over. What is a good way to normalize them (read on for what I mean by normalize)? All of the normalizing software I have seen uses the entire song for the window of normalzing. Basically makes determines a static value required to get the average volume of the song to the user defined level, then applies that value to the entire song. What I need is something that normalizes over a sliding window, or say 5 seconds, or whatever. In effect making soft spots louder, and crescendo's quieter. Not the way the music was intended to be heard, but perfect for music-at-work, or putting kids to sleep. Does anyone know of any software that does this? On a side note, I work for a Seismic processing company, and we do stuff like this all the time on Seismic waves, not sound waves. If I can't find any canned software to do this, I may modify some of our code to work with WAV files, but I don't want to reinvent the wheel."
it seems the music "industry" has been doing a very good job of this. What exactly you want is dynamic compression, not normalization. click here for more information.
I've used normalizer plugins in both XMMS and Winamp. They aren't perfect, but they're generally alright.
Check out http://volnorm.sourceforge.net/ for an XMMS plugin, or one of the many Winamp plugins here.
What you want is a compressor. Audacity (GPL software for Linux, Mac, Windows) includes a simple built-in compressor, and also works with compressor plug-ins like SC4 by Steve Harris. (You can get SC4 by installing the swh-plugins collection on Linux or Unix; it's also included with the Windows version of Audacity).
Yes iTunes calls it "Sound Check", and IIRC it normalizes the entire song.
/* oops I accidentally made a comment, sorry */
Classical music with its large dynamic ranges is meant to be loud at times. People think classical is something nice and calm like a little old lady, but much of it is meant to be exciting, and brash.
I'd do something interesting, but my server can't handle a slashdotting.
Give this plug-in for Winamp a try. It's called Rock Steady and I've been using it for a year or two at the office without a hitch.
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What you want is 'compression', not normalization. I don't mean data compression (ie. making smaller file), btw.
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Music studio use "compressors" to reduce the dynamic range of sound. Ones that work in real time have to be a bit sophisticated (sliding window, like you said), but doing it offline is easier, since you can know the max and min sound values beforehand.
I don't know what tools are out there in PC land, hopefully someone will answer. But I will mention that I used to have a portable CD player with a built in compressor (to help keep your music above the ambient background noise, espicially when driving) and it was GREAT! It is a feature that I don't see much in portable devices anymore, which surprises me...
Anyway, hopefully this might give you a new term to google for, at least. Try searching for "dynamic range compressor", or something...
Alright, I found some windows plugins that might help; Anyone with some Linux/MacOs/Unix equivalents?
http://www.divx-digest.com/software/tfm_filter.
http://www.divx-digest.com/software/dedynamic.
"It's overkill, of course. But you can never have too much overkill." - Anonymous Slashdot Coward
It sounds like volume equalization is what microsoft calls compression. Compression is where the amplitude of music is altered depending on the average amplitude of the last few moments of music. It's basically like the device/computer has its hand on the volume nob and tries to keep the volume comming out at the same level, which is exactly what the poster described. Any good sound editing program has compression effects and I would be supprised if many audio players didn't offer it as well. I know my creative nomad has the feature available. FYI, audio compression is also what radio stations use to make their station sound louder.
Have you tried using Replay Gain? It finds the psychoacoustic level of the music and calculates an appropriate gain correction. Replay gain is supported by foobar2000. MP3Gain is a tool that computes the replay gain for a track and changes the overall gain of the file.
Geez...I'm surprised nobody brought this up yet. MP3gain normalizes MP3's, but it NOT based on an average of the entire song. Read the site for more info. This is exactly the solution you are looking for.
MP3 Gain at Sourceforge
Sangloth
I'd appreciate any comment with a logical basis...it doesn't even have to agree with me.
http://trikuare.cx/code/AudioCompress.html
Works with most players -- xmms plugin as well.
Ratboy
Just another "Cubible(sic) Joe" 2 17 3061
I recommend the Volume Logic plugin for iTunes. It provides dynamic automatic gain control (AGC) over multiple bands. I find it really brings out the nuances in quiet music without blowing me away, when things get loud.
Michael.
Linux : Mac
> It sounds like volume equalization is what microsoft calls compression
It's pretty much a standard term.
> FYI, audio compression is also what radio stations use to make their station sound louder.
It's what TV advertisers do to make their station ads louder. FM transmissions pretty much have to be compressed. Get too loud with AM and you'll just clip and distort. Get too loud with FM, and you'll bleed into a neighboring station. Radio stations don't really like compression all that much, as it tends to cause listener fatigue.
Typical compression doesn't really need to sample the last few moments of music, it just clamps the volume to a baseline and reduces any positive or negative gains. If the song is highly dynamic, it simply hits a limiter, and just doesn't get any louder -- too soft usually isn't an issue except with classical.
Good compression normalizes over the entire track, but the term "normalization" usually applies to making the average volume level the same over several tracks of an album.
see subject
The audio processing algorithm being requested here is called "compression", and it's a standard feature of most audio editing package such as SoundForge. You can also buy hardware compressors for under $100 (dbx and Alesis make stereo compressors) that are good for hooking into a home stereo/theater system.
I keep an Alesis digital stereo compressor hooked into my home stereo system so that when loud spots (commercials, action scenece, etc) come on it doesn't suddenly get orders of magnitude louder and drive my apartment neighbors nuts.
Some DVD players have audio compression built-in as a feature. Some newer TV sets have it built-in also.
Moderator hint: a comment is neither "Flamebait" nor "Troll" if it is true.
for winamp there is a dsp plugin called tomsteady which does exactly this. i use it when i play mp3's at night.
It's a dynamic range control on mine (and actually called that, except in the advertising) - just flattens out the levels so you can hear people talking at a reasonable volume and when explosions and other loud parts of movies happen they are dropped back to "people talking" level so they don't make a racket. It's described in the book for my receiver.
I guess it probably depends on the receiver as well.
I drink to make other people interesting!
What you want is a compander. (compressor/expander). It is so called because it compresses or expands the dynamic range of the input audio. Sox includes one, if you like command lines.
.1,.1 -60,-10 0 0 .1
.1s to specify how fast it changes the volume; change the -60,-10 (always negative) to more similar values to make the compression less severe.
For winamp, I've found Rocksteady is beautiful, and does separate compression for several frequency bands (i can't begin to express how good this is for pop/rock).
For XMMS, AudioCompress does a sufficient job, although the windowing is somewhat stupid (not predictive == you'll get pops if things suddenly get loud) and it doesn't separate into multiple frequency bands, so it won't sound so good if you're playing something where the bass is really pushed (like Fiona Apple) next to something where it's not (classical).
Neither allow you specify complex transfer functions (of input volume to output volume).
For your purposes, sox is really the right thing, although it may feel a bit like "ack! drowning in sea of unexplained options!". You could start off trying:
$ sox infile.wav outfile.wav compand
will give you VERY hard compression. Change the
$ man sox
will tell you something more.
- KLS
SOX has a compand operator that lets you tune this stuff and parameters that let you tweak how fast it responds, how hard it attempts to correct the sound, and how fast it "lets go." Put this in line with your CD RIP process after you run a few through a test bed.
Don't forget to specify settings for each channel (normally two).
If you're willing to forego ID3 tags, or can hack them in yourself with mp3info, you can use cdda2wav to do sox processing: cdda2wav -O wav -t 7 -D /dev/cdrom - | sox [sox options] | lame - foo.mp3
Compression is a standard audio term, not an MS invention. Good description of what it does though. A compressor effects pedal is often used by guitarists because "turning up the volume" as the note decays away basically makes the note go on for ever (which is good for atmospheric guitar effects).
For the benefit of the original poster, if you want quiet relaxing classical music, try picking quiet relaxing pieces. If you're looking for a low-volume piece of music, why not just put in Metallica "Creeping Death" and turn the volume way down? Answer: cos it doesn't sound anything like how it's supposed to. So why not treat classical music the same, and listen to the music as it really sounds instead of in some distorted copy?
If you're having problems finding mellow classical music, buy more and you'll find plenty. Classical CDs are dirt cheap, so no reason not to. Deutsch Grammophon box sets are a good idea, incidentally. If you're still having trouble, much string quartet and chamber music has a fairly constant volume throughout.
Grab.
MP3Gain is the best program I've found. It doesn't normalize like other programs do. 'Instead, MP3Gain uses David Robinson's Replay Gain algorithm to calculate how loud the file actually sounds to a human's ears.'
This is what I use and it works like a charm...