I'm having very nice results with Audio::Play for playing sounds.

As for real time audio manipulation, I think you'd have to use PDL for anything complicated because of performance issues.

Also, (shameless plug here): Have you tried Audio::LADSPA? It uses ladspa plugins to do most of the real processing work, so it should be loads faster than pure perl. I'm not sure if any of the plugins can be compiled for win32, but it might be worth trying.

From the docs for Audio::LADSPA::Network

           use Audio::LADSPA::Network;
           use Audio::LADSPA::Plugin::Play;

           my $net = Audio::LADSPA::Network->new();
           my $sine = $net->add_plugin( label => 'sine_fcac' );
           my $delay = $net->add_plugin( label => 'delay_5s' );
           my $play = $net->add_plugin('Audio::LADSPA::Plugin::Play');

           $net->connect($sine,'Output',$delay,'Input');
           $net->connect($delay,'Output',$play,'Input');

           $sine->set('Frequency (Hz)' => 440); # set freq
           $sine->set(Amplitude => 1);   # set amp

           $delay->set('Delay (Seconds)' => 1); # 1 sec delay
           $delay->set('Dry/Wet Balance' => 0.2); # balance - 0.2

           for ( 0 .. 100 ) {
               $net->run(100);
           }
           $sine->set(Amplitude => 0); #just delay from now
           for ( 0 .. 500 ) {
               $net->run(100);
           }
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Good luck
Joost.

thanks for your quick reply.
i've already tried to use Audio::LADSPA, but for some reason it does not work on my machine...
maybe i was a bit too vague in my original question.
what i want is that everytime a new sample is generated, ie every time

        my $v2 = sin($counter/2*3.14) * 128 + 128;

        $data2 .= pack("c", $v2);
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generates new data, this data should be played by the soundcard.
this way, by including additional manipulations on $v2 using variables send to the subroutine by moving a scale-widget, the sound should change.
i also would like to program the filters, fx, etc myself (that is, if i am able to do so...)

Hmmm. I know for a fact that Audio::Play (should you decide to use it) uses floats for sample data and most pcm output hardware uses 16-bit words per sample. Your code assumes its 8-bits.

It's also probably more efficient to generate an @array of data first (say 100 samples) and then pack() it into a string and write it (Audio::Play can do this for you):

#!/usr/bin/perl -w
use strict;
use Audio::Play;
use Audio::Data;

my $player = Audio::Play->new();
while (1) {
    my $audio = Audio::Data->new( rate => 44100 );
    my @samples = map { sin ( 2 * 3.14 * $_ / 100 ) / 8 } 0 .. 99;  # 
+generate 100 samples as perl numbers
    $audio->data(@samples); # will pack() samples into floats
    $player->play($audio);
}
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This works perfectly on my machine.

Update:

To clarify: you really don't want to calculate and then play each sample seperately. It's incredibly inefficient so even most C - based softsynths don't do that.

What you want is a low latency between dragging a slider, and hearing the sound change. IMHO checking the slider state once for every 100 samples is enough:

Say you're running at 44100 Hz (normal CD sample rate), then playing 100 samples takes 100/44100 =~ 0.0023 seconds. That's probably fast enough for anything except really exact keyboard input, provided you don't have to sync your ouput with audio streams generated from outside your machine.

So, what you'd do is (pseudocode):

while (1) {
  check_for_input();
  update_parameters_for_new_input(); #possibly using heavy math
  generate_100_samples_as_fast_as_possible();
  push_samples_into_soundcard_buffer();
}
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Hope this clarifies.
Joost.
"What should it profit a man, if he should win a flame war, yet lose his cool?"

It is one of the benefits of using Win32. In other platforms, you wouldn't have it that easy.

You might try something like Buzz Machines. It is more than any other previous tracker-sampler, etc. It works with modules that might be added, created, etc.

i might include MIDI functions like SYNC (EXT) or an external start/stop function later but i want to build the synth so that it does create the sounds from scratch...

is there any way to get the Audio::play module as a ppd file ???

the buzz thing looks interesting, i'll have a look at that... thanks, b.

Buzz is very nice, I use it a lot myself, but it hasn't been maintained in years except for some binary patches because the sourcecode got lost. Writing plugins for it is pretty easy if you know a bit of C++ (alas, no perl, though there are some python bindings, apparantly).
"What should it profit a man, if he should win a flame war, yet lose his cool?"