[sdiy] Fast envelope generation
neil.johnson97 at ntlworld.com
Tue Dec 18 15:57:27 CET 2012
On 18 December 2012 13:44, Scott Gravenhorst <music.maker at gte.net> wrote:
> When I've needed an exponential response for an envelope, I've used a single pole
> lowpass IIR filt. So far, I've used this only for the release phase of an ADSR, but it
> works very nicely (in an FPGA) and I've not had a problem with it's computational expense.
> BUT - perhaps I don't understand what you are doing? Or am I confusing logarithmic and
A low-pass IIR filter is the obvious way of doing it as it models the
RC circuit of a real ADSR. And it is computationally simple:
But, you might be right Scott, perhaps there's something we're missing...?
Then again, if I was going to do a straight-line segment I'd use
Bresenham's algorithm rather than mess around with linear
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