Re: [LAU] [LAD] [ANN] CAPS 0.9.12

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To: Tim Goetze <tim@...>
Cc: LAU <linux-audio-user@...>, LAD <linux-audio-dev@...>
Date: Saturday, August 24, 2013 - 11:05 pm

On Sun, Aug 25, 2013 at 12:21:52AM +0200, Tim Goetze wrote:

> I'm planning to evade this problem by crossfading between two parallel

I doubt very much if that will provide a practiacal solution.
The state of the filter depends on signal history. Depending
on the parameters, this could be quite long. So you would
either have to

* run the new filter (with the new parameters) for some
time before crossfading, which will complicate the
code, or

* copy the state of the old into the new filter, but
with a biquad this can again produce quite heavy
spikes wich may last much longer than your crossfade.
This can happen even when both the new and old filter
are set to 0 dB gain.

The simple solution is to smooth the input parameters,
limiting their rate of change. Nobody expects an EQ
section to change from 100 Hz to 10 kHz in less than
half a second (unless it's a synth VCF module, but then
you definitely need something else than a biquad).

Ciao,

--
FA

A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)

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Messages in current thread:
[LAU] [ANN] CAPS 0.9.12, Tim Goetze, (Sat Aug 24, 1:16 pm)
Re: [LAU] [LAD] [ANN] CAPS 0.9.12, Fons Adriaensen, (Sat Aug 24, 2:45 pm)
Re: [LAU] [LAD] [ANN] CAPS 0.9.12, Tim Goetze, (Sat Aug 24, 7:59 pm)
Re: [LAU] [LAD] [ANN] CAPS 0.9.12, Fons Adriaensen, (Sat Aug 24, 9:48 pm)
Re: [LAU] [LAD] [ANN] CAPS 0.9.12, Tim Goetze, (Sat Aug 24, 10:24 pm)
Re: [LAU] [LAD] [ANN] CAPS 0.9.12, Fons Adriaensen, (Sat Aug 24, 11:05 pm)
Re: [LAU] [LAD] [ANN] CAPS 0.9.12, Tim Goetze, (Sun Aug 25, 12:03 am)
Re: [LAU] [LAD] [ANN] CAPS 0.9.12, mark hadman, (Sun Aug 25, 4:52 pm)
Re: [LAU] [LAD] [ANN] CAPS 0.9.12, Tim Goetze, (Sun Aug 25, 5:36 pm)
[LAU] 0.9.15, Re: [LAD] [ANN] CAPS 0.9.12, Tim Goetze, (Mon Aug 26, 4:20 pm)
Re: [LAU] 0.9.15, Re: [LAD] [ANN] CAPS 0.9.12, Julien Claassen, (Mon Aug 26, 9:08 pm)
Re: [LAU] 0.9.15, Re: [LAD] [ANN] CAPS 0.9.12, Tim Goetze, (Tue Aug 27, 11:46 am)
[LAU] [ANN] CAPS 0.9.13, Re: [LAD] [ANN] CAPS 0.9.12, Tim Goetze, (Sun Aug 25, 2:18 pm)
Re: [LAU] [ANN] CAPS 0.9.13, Re: [LAD] [ANN] CAPS 0.9.12, Fons Adriaensen, (Sun Aug 25, 4:47 pm)