How to save a WAV file using "AudioSystem" and "AudioInputStream"of JavaSound?

taroyamada

I'm on Processing 2.0.3 and tried to make a sound effect program which is not using real-time buffering and saves buffer (AudioInputStream) as .wav file after effecting, but my program doesn't work and gets the error :"Unhandled exception type IOException".

I couldn't a solution for this. Please advise me on how to save an AudioInputStream instans as .wav file.

---

import javax.sound.sampled.*;
import java.io.*;

void setup(){}
void draw(){}
void mousePressed(){
         byte[] pcm_data= new byte[44100*2];
         double L1      = 44100.0/440.0;
         double L2      = 44100.0/455.0;
         for(int i=0;i<pcm_data.length;i++){
            pcm_data[i]=  (byte)(55*Math.sin((i/L1)*Math.PI*2));
            pcm_data[i]+= (byte)(55*Math.sin((i/L2)*Math.PI*2));
            }

         AudioFormat      frmt= new AudioFormat(44100,8,1,true,false);
         AudioInputStream ais = new AudioInputStream(
                    new ByteArrayInputStream(pcm_data)
                   ,frmt
                   ,pcm_data.length);

         AudioSystem.write(
                    ais
                   ,AudioFileFormat.Type.WAVE
                   ,new File("test.wav"));
}

---

I read the article: http://forum.processing.org/one/topic/exception-type-ioexception.html ,and tried to write "try{---}catch (IOException e) {System.err.println(e);}", but the program didn't output .wav file and any error messages.

I searched some processing libraries for sound (examples:minim, Ess). But those are suitable for real-time playing, effecting and recording, so I use the JavaSound library directly. I suppose those libraries don't have save methods for non real-time array lists(?). If you know how to save non real-time buffer array list as .wav using minim or Ess, please advise me...

Thanks in advance for your help. I'm Japanese, so please, no flames about my bad English.

hamoid

I guess by now you already found the solution... Just in case:

import javax.sound.sampled.*;
import java.io.*;

void setup() {}
void draw() {}
void mousePressed() {
  byte[] pcm_data = new byte[44100*2];
  double L1 = 44100.0/240.0;
  double L2 = 44100.0/245.0;
  for (int i=0; i<pcm_data.length; i++) {
    pcm_data[i] = (byte)(55*Math.sin((i/L1)*Math.PI*2));
    pcm_data[i] += (byte)(55*Math.sin((i/L2)*Math.PI*2));
  }

  AudioFormat frmt = new AudioFormat(44100, 8, 1, true, true);
  AudioInputStream ais = new AudioInputStream(
    new ByteArrayInputStream(pcm_data), frmt, 
    pcm_data.length / frmt.getFrameSize()
  );

  try {
    AudioSystem.write(ais, AudioFileFormat.Type.WAVE, new 
      File(sketchPath + "/test.wav")
    );
  } 
  catch(Exception e) {
    e.printStackTrace();
  }
}

I changed 3 things: BigEndian (last argument in AudioFormat), divided the pcm_data.length by the frame size, and set an absolute path for the file.

taroyamada

Dear hamoid,

Thanks for answering. And the code you fixed is working!

GoToLoop

... and set an absolute path for the file.

It's more organized saving to "/data/" subfolder. So rather than new File(sketchPath + "/test.wav"),
this 1 points straight to "/data/": dataFile("test.wav"). :-c

Also, Processing already imports from lotsa "java.io" libraries already.
So import java.io.*; is usually redundant! :-j

hamoid

import java.io.*; is not redundant in this case.