Hi, this is a quite old project, so donīt look too much at the quality of the code. I always was interested in sound design. So I wrote various programs to compute sounds and to let them then be played with a sampler.

Youīll find the complete project at My Homepage

I know, that Perl isnīt perhaps the most suitable lang for this. Better said: Many people think this. What I wanted to do was a Virtual Sound Generator coupled wia WEB-Frontend and doing weird sounds, not necessary fast, but complex.

Feel free to use the snippets as you like - let me know if someone would like push this up. Some small examples:

Trivial additive synthesis. Shouldnīt be constrained to sinus only

#
# Fourier Synthesis
#
sub fourier {
    my ($s1,@spectrum) = @_;
    my $coef;
 
    foreach $coef (@spectrum) {
        my @fpa = split /_/, $coef;      # get frequency,phase and amp
+litude
        &osc::sinus($s1,$fpa[0],$fpa[1],$fpa[2],1);
    }
}
[download]

There are various oscilators in the package...and some neat low-level signal processing as for example:

#
# set the maximum amplitude to 1/-1
#
sub normalize {
    my $s1  = shift;
    my $max = &max($s1);
 
    &scale($s1,1/$max) if $max;
}
 
#
# reduce/expand the frequency of a given sample
#
sub redex {
    my ($s1,$new_freq) = @_;
    my $old_freq       = $$s1[$SMP_FREQ];
    my $cells          = $$s1[$SMP_CELLS];
    my $redex          = $new_freq / $old_freq;
 
    return if($redex == 1);                 # Nothing to be done
 
    my $newcells = $cells * $redex;
    my $a;
 
    if($redex > 1) {                        # Expand the original samp
+le
 
    } elsif($redex < 1) {                   # Reduce the original samp
+le
        for($a = 0; $a < $newcells; $a++) {
            $$s1[$a + $SMP_DATA] = $$s1[$a/$redex + $SMP_DATA];
        }
        $$#s1 = $newcells + $SMP_DATA;
    }
    $$s1[$SMP_CELLS] = $newcells;           # update the amount of cel
+ls in sample
}
[download]

Download it and feel free to expand, improve etc...

Ciao