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

[Alfons Adriaensen]

On Thu, Oct 05, 2006 at 09:14:26AM -0500, Andres Cabrera wrote:

> Just to clarify the problem I'm encountering, here's a zoom in on the 
> processed wave, exactly at the point where gain reduction starts 
> occuring. This screenshot doesn't apply any of the methods proposed in 
> the paper, it shows the output of the plugin. This behavior occurs for 
> the Tap, SC1 and SC4 plugins in Ardour, Audacity and Rezound. All 
> processed files were saved at 32-bit floating point.
> 
> www.geminiflux.com/Tap-processed.jpg

I just had a look at the TAP sources. The gain is only updated every
fourth sample, probably because the calculations to compute it involve
some functions that are not so cheap in CPU terms. This explains the
ripples.

The least that should be done is to interpolate the gain between these
points (introducing some latency). A better idea would be to simplify
the calculations - I haven't looked at them in detail but they seem
much too heavy for what's needed.


-- 
FA

Lascia la spina, cogli la rosa.