CODEMUSE

Fredrik – thanks for your kind comment. Yes I plan to release the source; I started cleaning up the comments and then got sidetracked (sounds familiar?). Meanwhile I am sending you the source without the final comments directly to your email address, so that you do not have to wait.

Tom – I sent you the source. Thanks for the feedback!

Thanks for your comment, Jason. Below is how I handle the pitch shift control in PlayWithMozart. The relevant variable in the code below is “pitchMod”. First are excerpts of the Audio loop; then the structure of the class “PianoWav”.
I hope this is helpful.

===========================================
// AUDIO LOOP
===========================================
private var pianoWav: PianoWav;
….
var in0: Sample; // one of 8 Samples (voices)
var outL: Number; // audio amplitude, Left channel
var outR: Number;
private var w0: WavFormat; // waves
private var s0: Number; // speed
private var a0L: Number; // amplitude
private var p0: Number; // phase

// PITCH MODULATION; SET BY SLIDER
var pitchMod: Number = KUI.uiSliders.paramPitch.getValue();

// INSIDE AUDIO OUTER LOOP
// … when new note:
s0 = pianoWav.aDPhase[ currNoteMidi ] * pitchMod;
uLen0 = w0.samples.length – stepsInnerLoop * s0;
….
w0 = pianoWav.aWavPtr[ currNoteMidi ];
s0 = pianoWav.aDPhase[ currNoteMidi ] * pitchMod;

// INSIDE AUDIO INNER LOOP
in0 = w0.samples[ int( p0 ) ]; // phase changes every sample
p0 += s0;

outL += in0.left * a0L;
outR += in0.right * a0R;

< -- insert audio effects here -->

//– store local
out = samples[i]; // for every sample
out.left = outL; // write to sample
out.right = outR;

< -- end of inner loop -->
< -- end of outer loop -->

===========================================
// STRUCTURE OF CLASS PianoWav … index of arrays is Midi note 0..108
===========================================
public class PianoWav {

[ArrayElementType("int")]
// points to wav array of “f” pitch piano notes; one for each of 7 octaves
public var aWavPtr: Array;
[ArrayElementType("int")]
public var aDPhase: Array; // populates step in samples (or “speed”)
….
< -- for each iMidi note -->
aWavPtr[iMidi] = aFa0to6[ixFa0to6] ; // just pointer
var midiFA: int = midiF1 + ixFa0to6 * 12;
// Creates the phase increment for each midi note
var dPhase: Number = dPhase0 * Math.pow( 2.0, (iMidi – midiFA) / 12.0);
aDPhase[iMidi] = dPhase;
…..

Kenny – I sent you the source code. Hope it helps.

Hi John F – Thanks for your feedback!
PlayWithMozart plays up to 8 samples concurrently (new notes/chords plus the tail end of previous notes/chords). You can actually see the number of voices playing at any one time if you click the “Audio” tab, after you have drawn the outline of your melody.
Once you get your code to play one voice, it should be relatively easy to get it to play more than one voice at one time. The basic idea for the code comes from the examples in popforge’s library: fetch the current value of every sample (adjusting the amplitude as needed) and add all sample values (additive synthesis) before storing the result in the buffer. Separately, I am sending you the source code and you will be able to see how I did it — look in the file MainLoop.as
I hope this helps
jmbara

Prajwal, since with Popforge you are dealing with sounds at the byte level, it is easy to have more than one voice. PlayWithMozart adds the samples (additive synthesis) of up to 8 simultaneous stereo voices (in this case stereo piano sounds) before they are stored in the audio playback buffer. Alternatively one could generate FM synthesis by multiplying two streams of bytes (if I remember correctly the Popforge distribution also has an example of FM synthesis).

Jonas, if you can develop a way to access the ogg sounds at byte level, there should be no reason one could not use these sounds with Popforge. This would circumvent the need to package the sounds in furnace format. I am not volunteering to participate in this effort because I do not have the time right now but I would be very interested in seeing the results.

Chris, Jez, David and Prajwal, I sent you PlayWithMozart’s source code earlier today.

Jmbara

Patrick and Aden – I have sent you both the source (Aden, sorry for the delay). Patrick — You will see in the source that PlayWithMozart can manipulate and play 8 voices simultaneously. The number of voices is only limited by the host computer CPU. I don’t know how to use MP3 though; I used Andre Michelle and Joa Ebert’s furnace format and all soundfiles get loaded into memory at the start. To save memory, I only load seven piano sounds, about one per octave; all the other 101 MIDI pitches are produced on the fly by varying the sampling rate. Using more sounds would enrich the dispersion of timbres, but one per octave seemed good enough to fool the ear (at least my ear!).

Betty – I sent you the source code. I hope this helps you with your question on how to pitch sounds with popforge. You will see in the source code that I generate all semitones of the grand piano keyboard by pitch shifting only 7 original sounds (notes). This economy of stored sounds also helps speed up the initial sound loading times.
When you have PlayWithMozart running, after you draw the outline of the melody, try clicking on the “Audio” tab and then moving the BPM (Beats Per Minute without pitch shifting) and TUN (pitch shifting) sliders. This illustrates the flexibility of the popforge framework.
Good luck with your project — I would love to see the results.
Thanks for your comments!

Jan – I sent you the source code. PlayWithMozart uses sampled sounds; of course, to emulate the KAOS you will want to synthesize your own sounds rather than using samples — if you haven’t already, you can find examples of simple software synths in the popforge library. Good luck with your project!

Gerald – I sent you the source code. To see how I implemented the timer look for the file KClock.as. The timer gets incremented by the main loop in MainLoop.as. I look forward to seeing your BPM timer keeper.

Adam – Am glad to share the source code — I’ve sent it to you. I’d be interested in seeing your piano song composition program when it is finished.

Hi Chris – I sent you the source code for PlayWithMozart – I hope it helps. Just to make sure credit goes where it is due: Andre Michelle and Joa Ebert sorted out the sound timing issues with their Popforge library, so I did not have to worry about that. Good luck with your project!