Java Audio Clips on Pi

[Sam Ritter]

This is not really a Java question but I am trying to find someone with experience writing Java for a Pi that plays clips. I have determined that the default mixer (0) does not work so I had to select a different one (1).

Mixer.Info[] mixers=AudioSystem.getMixerInfo();
		if (Functions.isPi()) {
			useMixer=mixers[1];
		}
		else {
			useMixer=mixers[0];
		}

public static boolean isPi() {
		boolean pi=false;
		if (System.getProperty("os.name").toLowerCase().equals("linux")) {
			File file = new File("/etc", "os-release");
			try {
				FileInputStream fis = new FileInputStream(file);
				BufferedReader br = new BufferedReader(new InputStreamReader(fis));
				String string;
	            while ((string = br.readLine()) != null) {
	                if (string.toLowerCase().contains("raspbian")) {
	                    if (string.toLowerCase().contains("name")) {
	                        pi=true;
	                    }
	                }
	            }
	            br.close();
			}
			catch (Exception e) {
				// ignore exception
			}
		}
		return(pi);
	}

Here is how I play clips:

private synchronized void playSound(final String path_) {
		  new Thread(new Runnable() {
		    public void run() {
		    	if (clip!=null) {
		    		clip.stop();
		    	}
		    	try {
		    		clip = AudioSystem.getClip(Configuration.getInstance().useMixer);
		    		BufferedInputStream bufferedIn=new BufferedInputStream(this.getClass().getClassLoader().getResourceAsStream(resourcesPath+path_));
		    		AudioInputStream inputStream = AudioSystem.getAudioInputStream(bufferedIn);
		    		clip.open(inputStream);
		    		clip.loop(Clip.LOOP_CONTINUOUSLY);
		    	}
		    	catch (Exception e) {
		    		JOptionPane.showMessageDialog(null,"Audio clip ("+resourcesPath+path_+") error - "+e.toString(),"Stoker Monitor",JOptionPane.WARNING_MESSAGE);
		    	}
		    }
		  }).start();
		}

This all works but only for a while. At some point when the app tries to play a clip (which it has before during the same run) I get an error telling me the mixer is not supported. The error is obviously dumb because the mixer worked for a while and only occurs on a Pi. Other *NIX work fine. If I end and restart the application then it will work again for a while. I have verified that it is always using the same mixer before and when it fails. Again this does not seem like a Java problem but rather a Pi problem but I don't know what to do to debug or fix it. Unfortunately there does not seem to be much Java expertise on the Pi forum that can help. TIA.