Well, I’m not really a Sound library user, so I missed read() (which can write out the frame data).
HERE IS THE SOLUTION:
A copy method for SoundFile:
AudioSample copySoundFile(SoundFile file) {
float[] data = new float[fileIn.frames()];
file.read(data);
return new AudioSample(this, data);
}
To try it out:
- open Examples > Libraries > Sound > Soundfile > JumbleSoundfile
- add the copySoundFile method from above
- replace global variables and setup as follows, leaving the rest of the sketch as-is
import processing.sound.*;
SoundFile fileIn;
AudioSample file;
void setup() {
size(640, 360);
background(255);
// Load a soundfile and start playing a copy on loop
fileIn = new SoundFile(this, "beat.aiff");
file = copySoundFile(fileIn);
file.loop();
}
- Add a reset method to demonstrate that the copy data and the original are different.
void keyPressed() {
file.stop();
file = copySoundFile(fileIn);
file.loop();
}
The demo will work, running on the copied AudioSample object rather than on the original file. Click repeatedly to jumble the (copied) sample. Press any key to reset the playing sample to the original file load, then jumble again – all with in-memory copying, without ever loading a new SoundFile object from the file system.
// JumbleSoundfileCopy
/**
* First load a sample sound file from disk, then start manipulating it using the
* low-level data access functions provided by AudioSample.
* With every mouseclick, two random 1 second chunks of the sample are swapped around
* in their position. The sample always stays the same length and it keeps on looping,
* but the more often you do random swaps, the more the original soundfile gets cut up
* into smaller and smaller portions that seem to be resampled at random.
*/
import processing.sound.*;
SoundFile fileIn;
AudioSample file;
void setup() {
size(640, 360);
background(255);
// Load a soundfile and start playing a copy on loop
fileIn = new SoundFile(this, "beat.aiff");
file = copySoundFile(fileIn);
file.loop();
}
AudioSample copySoundFile(SoundFile file) {
float[] data = new float[fileIn.frames()];
file.read(data);
return new AudioSample(this, data);
}
void keyPressed() {
file.stop();
file = copySoundFile(fileIn);
file.loop();
}
void draw() {
}
void mousePressed() {
// Every time the mouse is pressed, take two random 1 second chunks of the sample
// and swap them around.
int partOneStart = int(random(file.frames()));
int partTwoOffset = int(random(file.frames() - file.sampleRate()));
// Offset part two by at least one second
int partTwoStart = partOneStart + file.sampleRate() + partTwoOffset;
// Make sure the start of the second sample part is not past the end of the file.
partTwoStart = partTwoStart % file.frames();
// Read one second worth of frames from each position
float[] partOne = new float[file.sampleRate()];
float[] partTwo = new float[file.sampleRate()];
file.read(partOneStart, partOne, 0, partOne.length);
file.read(partTwoStart, partTwo, 0, partTwo.length);
// And write them back the other way around
file.write(partOneStart, partTwo, 0, partTwo.length);
file.write(partTwoStart, partOne, 0, partOne.length);
}