SPEC: MidiChannel.getController() spec is incomplete or ambiguous

Name: vtR10009 Date: 07/25/2002


  Specification for the method MidiChannel.getController(int controller) from
the package javax.sound.midi is ambiguous:
"Obtains the current value of the specified controller. The return value is
represented with up to 14 bits; the resolution is dependent on the controller
number. For controllers 0-31, the resolution is always 14 bits.
  Returns: the current value of the specified controller"

  It is not clear should the method getController() return entire 14-bit
value for controller numbers 0-31, or MSB value? And what values should
be returned for 32-63 controller numbers.

Method controlChange() sets the values separatly. But actually
current MidiChannel implementation for default synthesizer returns
7-bit value for MSB controller numbers. This behavior contradicts
to the spec that return value is represented with up to 14 bits.
  
This bug may affect new JCK test:
  api/javax_sound/midi/MidiChannel/index.html#control
  
To reproduce the bug run the following test with JDK build 1.4.1-rc-b17:
------------------------------- test.java --------------------------------
import javax.sound.midi.*;
import javax.sound.sampled.*;

public class test{

    static boolean isSoundAccessDenied = false;
    {
        SecurityManager securityManager = System.getSecurityManager();
        if (securityManager != null) {
            try {
                securityManager.checkPermission(new AudioPermission("*"));
            } catch (SecurityException e) {
                isSoundAccessDenied = true;
            }
        }
    }

    public static void main(String args[]) {
        Synthesizer synth = null;
        MidiChannel mChanArr[];
        MidiChannel chan = null;
        boolean failed = false;
        int i = 0;
        int chanNum = 0;
    
        int val = 16;
        int contr = 39; //Channel volume LSB
    
        try {
            synth = MidiSystem.getSynthesizer();
            synth.open();
            mChanArr = synth.getChannels();
            while ((i < mChanArr.length) && (chan == null)) {
                chanNum = i;
                chan = mChanArr[i++];
            }
            if (chan == null) {
                System.err.println("No channels in this synthesizer!");
                System.exit(0);
            }
     
            chan.controlChange(contr, val);
    
            if (chan.getController(contr) != val) {
                System.out.println("Controller(" + contr +") does not
supported. It's Ok. "
                        + " value: " + chan.getController(contr));
            }
    
            //Channel volume MSB
            chan.controlChange((contr - 32), val);
    
            if (chan.getController(contr - 32) != (val*7)) {
                failed = true;
                System.err.println("Controller(" + (contr - 32) + ") does not
return proper"
                        + " value: " + chan.getController((contr - 32)));
            }
    
            //Channel volume LSB
            if (chan.getController(contr) != 0) {
                failed = true;
                System.err.println("Controller(" + contr +") does not return
proper"
                        + " value: " + chan.getController(contr));
            }
    
            
        } catch (MidiUnavailableException mue) {
            System.err.println("MidiUnavailableException was thrown: " + mue);
            System.err.println("could not test.");
        } catch(SecurityException se) {
            if (isSoundAccessDenied) {
                System.err.println("No permissions to "
                        + "open device!");
                System.exit(1);
            }
            se.printStackTrace();
            System.err.println("Sound access is not denied but "
                    + "SecurityException was thrown!");
        } finally {
            if (synth != null) synth.close();
        }
    

        if( failed ) {
            System.err.println("test failed");
            System.exit(1);
        } else {
            System.out.println("OKAY");
            System.exit(0);
        }
        
    }
}

---------------------------Logs-------------------------------------------
novo101:templates$ javac test.java; java -showversion test
java version "1.4.1-rc"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1-rc-b17)
Java HotSpot(TM) Client VM (build 1.4.1-rc-b17, mixed mode)

Controller(39) does not supported, It's Ok, value: 0
Controller(7) does not return proper value: 16
test failed
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