[LAU] Fwd: Normalizing Audio Levels using RMS

[hollunder at gmx.at]

> 
> 4. ReplayGain does not work with wav files, I believe. Also, it does
> not change the gain, only gives instructions to Amarok (am I right
> here?) by writing some code to the ID3 tag of an mp3 file.
> 
> Thanks to all for your replies - if you come to some other ideas,
> please do write.
> 
> Viktor

I only know a bit more about replaygain. It's originally designed for
playback, to get all those commercially mastered albums and tracks to
the same level so you don't need to twist the volume knob all the time.
That's why it usually writes the adjustment information into tags that
the player can read and adjust volume accordingly (a CD is a final
product, you don't want to change it as listener).

Anyway, there are programs for most formats available, the one you are
looking for is called wavegain [1]. Replaygain works either on tracks or
albums, so take track on some file and it calculates/adjusts that file.
wavegain doesn't use tags afaik but changes the file directly, maybe
with limited granularity, but when you say that 1.5dB is fine I'm sure it can do that.

The levels replaygain uses are 83dB originally and 89dB in practise for
some reason. But this can be adjusted, you just need to figure out how
these 89dB relate to other figures you know/need. There was a lengthy
thread somewhere on the hydrogenaudio forums that explained how these
dB are calculated but I can't find it atm.

So even if it's not made for that purpose it can work.
It would be neat if someone would write a implementation that could be
used for what you are doing more easily, maybe as a plug-in if that's
somehow possible.

[1] http://www.rarewares.org/others.php#wavegain

Best regards,
Philipp