1. The signal[] array contains the most recent sample data after calling LiveInput.getSignal(). For performance reasons it is not updated automatically, so you'll have to call the function explicitly (and repeatedly) BEFORE working with the array. The values are indeed 16bit signed, however stored as float.

2. The array has twice as many elements as you specified for the LiveInput.start(num) call. If no number was given, Sonia initializes with a default window size of 1024 bins (or 2048 samples). At 44.1kHz that equals chunks of approx. 46ms length...

3. Internally Sonia maintains a circular buffer. However, this is abstracted away from the user and the signal[] array will always only contain the X most recent samples (with signal[0] being the oldest of them)

hth!

toxi - Thanks for the fabulous reply.  Is there more documentation on Sonia than what's available at sonia.pitaru.com?  Things like getSignal() and signal[] are not shown there... wondering what other Easter eggs are hiding?

dj hype

i'm not surprised at all that your sketch is creating inconsistent results since you always only manage to read parts of the original sample at only more or less regular intervals...

You initialize LiveInput with the default setting, so the time window used is 2048 samples long (approx. 46 milliseconds).

Now, since you didn't specify any framerate Processing will attempt to run your sketch as fast as possible, meaning draw() is executed at unpredictable time intervals (probably faster than the 46ms per audio frame). Yet every draw frame you recalculate the spectrum as if it would be an entire new audio buffer and with the same assumption also add the latest signal to your array - with the result of you probably getting loads of duplicate (or missing) sample values, depending if your sketch is running faster or slower than realtime.

Am actually embarking on a similar tool than you and haven't really looked yet into how to solve this properly. But having had a brief look at the available Sonia methods I'd try to progress reading the sample "manually" via this method:

Code:

mySample.read(dataArray, firstDataFrame, firstSampleFrame, numFrames); 

You'd then need a audio frame counter variable and read and process a new frame at every draw() iteration. Hope that works, haven't tried it yet...

here is another quick test program which uses both versions of the read method. here the number of output values vary intensely. the frame counter works... im not sure how the second version of read works.

import pitaru.sonia_v2_9.*;

Sample mySample;  
float[] sample_data;
boolean once = false;

int current_frame, last_frame, frame_amount, frame_count;

void setup(){

 size(200,200);  
 ellipseMode(CENTER);
 rectMode(CENTER);
 noStroke();

 Sonia.start(this);
 LiveInput.start();
 mySample = new Sample("hello.wav");  
 mySample.setRate(10);
 mySample.play();  
 mySample.connectLiveInput(true);  

 framerate(100);

 current_frame = 0;
 last_frame = 0;
 frame_amount = mySample.getNumFrames();

 sample_data = new float[mySample.getNumFrames()];
 mySample.read(sample_data);

 String[] sample_data_strs = new String[mySample.getNumFrames()];

 for (int i=0; i < sample_data.length; i++) {
   sample_data_strs[i] = str(sample_data[i]);
 }

 saveStrings("sample_data_1.txt", sample_data_strs);

 sample_data = new float[mySample.getNumFrames()];
}

void draw(){
 background(255);

 if(mySample.isPlaying()){  
   if(last_frame != mySample.getCurrentFrame()) {
     last_frame = frame_count;
     frame_count++;
     println("the sample is currently on frame:" + frame_count);
     //mySample.read(sample_data, sample_data.length-1, frame_count, 1);
     mySample.read(sample_data, frame_count, frame_count, 1);
   }      
   //println("the sample is currently on frame:" + mySample.getCurrentFrame());
 }  
 else if(!mySample.isPlaying()){  
   if(!once) {
     String[] sample_data_strs = new String[mySample.getNumFrames()];

     for (int i=0; i < sample_data.length; i++) {
       sample_data_strs[i] = str(sample_data[i]);
     }

     saveStrings("sample_data_2.txt", sample_data_strs);
     println("SAMPLE DATA SAVED");
   }    
 }
}

Q-
Are you speaking of the dialog box that comes up when you try to run the applet in a browser?  It seems to just hang, forcing me to force-quit (Safari on OS X.4.6).  Maybe I'll try version 0090...