6 May
2003
6 May
'03
8:15 a.m.
Hallo,
nickt hat gesagt: // nickt wrote:
Sorry if this is the wrong list. I have never found a
list with people
who can help me with these kind of questions.
Check out the code archive on musicdsp.org.
I am trying to figure out how a rectifier works in
code. I have created
something like it using tanh() distribution ( which will turn a sine
wave into a sort-of-square wave). I can also achieve it with hard
clipping/saturation. In the same sense I'd also like to know how a
smooth operation works as well. I can not find any source code or
explanations to help me figure out the algorithm yet.
Musicdsp has several examples and you also could take a look at
Steve's plugins. There are several ways to rectify a signal. The
hardest way is doing convolution with a matching impulse response. The
easiest way seems to be waveshaping: There you use a lookup table that
multiplies your input signal with values that smoothly approach 0 when
your signal approaches 1.
My other question is how are exponential signals
generated? I want to
experiment with exponential FM. My only understanding of Exp. Fm is that
it sweeps half down and full up ( at 440hz, it would sweep 220hz down
and 880 hz up). I haven't much of an idea how this is achieved. How do I
convert a sine wave into an exponential signal for Exp FM?
I don't quite understand this. To sweep the frequency, you just apply
a function on the frequency input. Simplified like
out = sin(exp(freq))
ciao
--
Frank Barknecht _ ______footils.org__