I'm getting these errors:

Then I found this:  http://processing.org/discourse/yabb2/YaBB.pl?num=1274221471/3

I think the problem is related to audio on Java on Ubuntu. I tried doing what that post suggest, copying two audio libraries from OpenJDK to JavaSun, but it did not help.

Feels a bit silly because I wanted to record the last episode of Fun Programming for this year showing how to make rhythms but I can't make the sound work properly.

I did not remember that Processing came with its own Java, so my attempts to fix java-6-sun did not help.

But these lines did:

1. sudo cp /usr/lib/jvm/java-6-openjdk/jre/lib/i386/libpulse-java.so ~/Desktop/processing-1.5.1/java/lib/i386/
2. sudo cp /usr/lib/jvm/java-6-openjdk/jre/lib/ext/pulse-java.jar ~/Desktop/processing-1.5.1/java/lib/ext/
3. sudo cp /etc/java-6-openjdk/sound.properties ~/Desktop/processing-1.5.1/java/lib/

I'm not sure if the next lines are necessary, but since pulse-java.jar and libpulse-java.so were owned by root, I changed the owner to match the rest of the Processing installation. 

1. sudo chown MYUSR:MYUSR ~/Desktop/processing-1.5.1/java/lib/ext/pulse-java.jar
2. sudo chown MYUSR:MYUSR ~/Desktop/processing-1.5.1/java/lib/i386/libpulse-java.so
3. chmod +x ~/Desktop/processing-1.5.1/java/lib/i386/libpulse-java.so

I think these changes should not be done by the user, but Processing should come already with the Pulse audio libraries. Otherwise sound in Processing with Ubuntu is broken.

Vanilla JavaSound on Ubuntu probably only has one little-endian output available, so when you try to load two little-endian files, the first one snags the output and the second one is left high and dry. The Pulse audio library probably has some service provider stuff in it that makes a Mixer available to JavaSound that can handle more than one little-endian output, so no worries there. 

I just took a look over the code that generates these errors and as far as I can tell, I'm doing the right thing. I generate a DataLine.Info object using the AudioFormat of the file you are trying to load and then ask AudioSystem if that kind of line is supported. Then, if you've set an outputMixer for Minim, I ask for a SourceDataLine from that, but if you haven't, I ask AudioSystem. I'm guessing you haven't set an outputMixer, so it's probably asking AudioSystem in your case. That should be fine, it would query all of the Mixers the system knows about and return a SourceDataLine from the first one that could support it.

The annoying thing here is that one might expect AudioSystem.isLineSupported to return false if none of the Mixers actually have a SourceDataLine available for the format in the DataLine.Info, but it probably considers "support" to be different from "is one available right now".

I'm curious to know if there's anything I can do in Minim to remove the need for Pulse in this situation. I'll make a note of this issue and have a look at some point.

Another good side effects of using Pulse is that now I can record the sound output generated by Processing using the audio recorder or any other application. Before I could not do that.

One more curious effect was that, since I have an internal sound card and a USB one, the system was using the USB card, but Processing used the internal one. I could not control that. I couldn't control the volume of Processing either. I could go as far as muting the computer, but Processing ignored that, and played full volume.

If you want to avoid the use of Pulse I guess Minim should somehow mix the audio internally, but I have no idea if that's possible or easy. 

I'm happy having found a workaround. Now I can record a video explaining how to make some randomized rhythms :)

Processing uses the internal sound card because that's what JavaSound gives it by default. If you were to explicitly set the output Mixer using setOutputMixer, you could probably get Processing to play through the USB card.

If I list the mixers with AudioSystem.getMixerInfo() I only ever get back mixers that have inputs in them, which means that I can't select my gigaport HD+ which has only outputs on it as it never shows up in the list that's returned.

I thought I could trick it by using Audio Midi Setup (part of mac os x) to create an agregate audio device, with some inputs and outputs on it. Doing that makes it show up in the mixerInfo[] array, but still does not let me select outputs with minim.setOutputMixer.

When I tried using two outputs to anything other than Java Sound Audio Engine, like this:

2. import ddf.minim.*;
3. import ddf.minim.signals.*;
4. 
   
5. import javax.sound.sampled.*;
6. import javax.sound.*;
7. 
   
8. Minim minim;
9. AudioOutput out;
10. MouseSaw msaw;
11. Mixer.Info[] mixerInfo;
12. 
    
13. int mixerID = 3;
14. 
    
15. int channels = 2;
16. 
    
17. 
    
18. void setup()
19. {
20.   size(1280, 1024);
21. 
    
22.   minim = new Minim(this);
23. 
    
24.   mixerInfo = AudioSystem.getMixerInfo();
25.   for (int i = 0; i < mixerInfo.length; i++) {
26.     println (i+" "+mixerInfo[i].getName());
27.     println ("  desc:"+mixerInfo[i].getDescription());
28.     println ("  vendor:"+mixerInfo[i].getVendor());
29.      
30.   }
31. 
    
32.   println("chosen mixer:"+ mixerID);
33.   AudioFormat af = new AudioFormat( (float )44100, 16, 1, true, false );
34.   
35.   minim.setOutputMixer(AudioSystem.getMixer(mixerInfo[mixerID]));
36. 
    
37.   out = minim.getLineOut(channels);
38.   msaw = new MouseSaw();  
39.   out.addSignal(msaw);
40. }
41. 
    
42. void draw()
43. {
44.   background(0);
45. }
46. 
    
47. 
    
48. 
    
49. void stop()
50. { 
51.   if ( out != null ) {
52.     out.close();
53.   }
54.   minim.stop();
55. 
    
56.   super.stop();
57. }
58. 
    
59. 
    
60. 
    
61. class MouseSaw implements AudioSignal
62. {
63.   void generate(float[] samp)
64.   {
65.     float range = map(mouseX, 0, width, 0, 1);
66.     float peaks = map(mouseY, 0, height, 1, 20);
67.     float inter = float(samp.length) / peaks;
68.     for ( int i = 0; i < samp.length; i += inter )
69.     {
70.       for ( int j = 0; j < inter && (i+j) < samp.length; j++ )
71.       {
72.         samp[i + j] = map(j, 0, inter, -range, range);
73.       }
74.     }
75.   }
76. 
    
77.   // this is a stricly mono signal
78.   void generate(float[] left, float[] right)
79.   {
80.     generate(left);
81.     generate(right);
82.   }
83.   void generate(float[] left, float[] right, float[] three, float[] four, float[] five)
84.   {
85.     generate(left);
86.     generate(right);
87.     generate(three);
88.     generate(four);
89.     generate(five);
90.   }
91. }

I get:

2. sublime_setOutputMixer.pde:36:0:36:0: IllegalArgumentException: Line unsupported: interface SourceDataLine supporting format PCM_SIGNED 44100.0 Hz, 16 bit, stereo, 4 bytes/frame, little-endian
3. Exception in thread "Animation Thread" java.lang.IllegalArgumentException: Line unsupported: interface SourceDataLine supporting format PCM_SIGNED 44100.0 Hz, 16 bit, stereo, 4 bytes/frame, little-endian
4. at com.sun.media.sound.SimpleInputDevice.getLine(SimpleInputDevice.java:142)
5. at ddf.minim.javasound.JSMinim.getSourceDataLine(Unknown Source)
6. at ddf.minim.javasound.JSMinim.getAudioOutput(Unknown Source)
7. at ddf.minim.Minim.getLineOut(Unknown Source)
8. at ddf.minim.Minim.getLineOut(Unknown Source)
9. at sublime_setOutputMixer.setup(sublime_setOutputMixer.java:57)
10. at processing.core.PApplet.handleDraw(PApplet.java:2241)
11. at processing.core.PGraphicsJava2D.requestDraw(PGraphicsJava2D.java:243)
12. at processing.core.PApplet.run(PApplet.java:2140)
13. at java.lang.Thread.run(Thread.java:680)