Rockbox mail archiveSubject: Re: FS#10199: Limiter DSP function
Re: FS#10199: Limiter DSP function
From: Jeff Goode <jeffg7_at_gmail.com>
Date: Mon, 17 Aug 2009 10:47:25 -0400
Thomas Martitz wrote:
> It's basically replaygain with clipping prevention, with the
> differences that only the passages that are too lout is scaled down by
> a few dB, not the whole file...IIUC
> I don't really see a sense in the feature, but I'm not opposed either.
This isn't a reimplementation of replaygain. The problem with
replaygain w/clipping is that it will raise (or even lower) the entire
signal so that the max peak is at the clipping limit. This is fine if
all you wish to do is normalize the volume of the entire track or
album. It does nothing to address the fact that within the same track
you can have passages that play at -40dB followed by passages at 0dB.
So either the quiet passages go unheard, or you turn up the volume to
hear them and are blown away by the loud stuff, or you know it's coming
and work the volume up and down accordingly. This DSP function "knows
it's coming" and works the volume for you, no more, no less.
In fact, I recommend that you use it with replaygain since with the
signal normalized, you can minimize the amount of preamp you need to get
the desired effect. But it's an enhancement, not a replacement.
Received on 2009-08-17