[linux-audio-dev] Paper on dynamic range compression

[Fons Adriaensen]

On Mon, Oct 16, 2006 at 07:48:35PM +0100, Dan Mills wrote:

> The gain control signal has energy right the way out
> to the band limit (and probably aliased around it),
> never mind what happens when that hits the multiplier!

The question is: how much of this HF energy is there ?

There shouldn't be much in a compressor with controlled
attack / release times. In that case it is always possible
to filter the control signal. In fact the obvious way to set
attack / release times is by such filtering !
 
A fast peak limiter could still do this. But even here it can
be avoided by look-ahead, i.e. having a short delay on the
audio which in turn allows a finite attack time.

A fast limiter needs a higher sample rate or interpolation
anyway, just to detect the correct peak level. Remember that
'THE SAMPLES ARE NOT THE SIGNAL'. The real peak level of a
signal when converted to the analog domain can be several
dB above that of the highest sample.

-- 
FA

Lascia la spina, cogli la rosa.