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

[Andres Cabrera]

John Rigg wrote:
> On Thu, Oct 05, 2006 at 09:01:19AM -0500, Andres Cabrera wrote:
>   
>> I was assuming that RMS measruments and windowed integration act as a 
>> high pass filter, is this not true?
>>     
>
> No, a low pass filter integrates and a high pass filter differentiates.
>
>   
Yes, I meant low pass filter.... Maybe the window size or something 
similar has to do with the apparent high pass filtering?

Andrés


> The audio signal is rectified before it can be filtered and used for
> gain control, so there is no AC signal for the filter to act on,
> just a varying DC level. The time constants for the filter
> (eg. charge and discharge rates on a capacitor in an analog LP filter)
> determine the rate at which the control signal can increase or
> decrease, and hence the attack and decay times.
>
> John
>
>