Merge pull request #42 from philburk/startrequired

add isStartRequired, add GroupChannel to synth

13 files changed, 158 insertions, 89 deletions

diff --git a/src/com/jsyn/data/AudioSample.java b/src/com/jsyn/data/AudioSample.java
index 42d8501..dcbbae5 100644
--- a/src/com/jsyn/data/AudioSample.java
+++ b/src/com/jsyn/data/AudioSample.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -20,13 +20,13 @@ import java.util.ArrayList;
 
 /**
  * Base class for FloatSample and ShortSample.
- * 
+ *
  * @author Phil Burk (C) 2010 Mobileer Inc
  */
 public abstract class AudioSample extends SequentialDataCommon {
     protected int numFrames;
-    protected int channelsPerFrame;
-    private double frameRate;
+    protected int channelsPerFrame = 1;
+    private double frameRate = 44100.0;
     private double pitch;
     private ArrayList<SampleMarker> markers;
 
@@ -61,7 +61,7 @@ public abstract class AudioSample extends SequentialDataCommon {
 
     /**
      * Set the recorded pitch as a fractional MIDI semitone value where 60 is Middle C.
-     * 
+     *
      * @param pitch
      */
     public void setPitch(double pitch) {
@@ -89,7 +89,7 @@ public abstract class AudioSample extends SequentialDataCommon {
     /**
      * Add a marker that will be stored sorted by position. This is normally used internally by the
      * SampleLoader.
-     * 
+     *
      * @param marker
      */
     public void addMarker(SampleMarker marker) {
diff --git a/src/com/jsyn/unitgen/ChannelOut.java b/src/com/jsyn/unitgen/ChannelOut.java
index 5eafacc..89f778b 100644
--- a/src/com/jsyn/unitgen/ChannelOut.java
+++ b/src/com/jsyn/unitgen/ChannelOut.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -20,7 +20,7 @@ import com.jsyn.ports.UnitInputPort;
 
 /**
  * Provides access to one channel of the audio output.
- * 
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc
  * @see ChannelIn
  */
@@ -40,6 +40,14 @@ public class ChannelOut extends UnitGenerator {
         this.channelIndex = channelIndex;
     }
 
+    /**
+     * This unit won't do anything unless you start() it.
+     */
+    @Override
+    public boolean isStartRequired() {
+        return true;
+    }
+
     @Override
     public void generate(int start, int limit) {
         double[] inputs = input.getValues(0);
diff --git a/src/com/jsyn/unitgen/FixedRateMonoWriter.java b/src/com/jsyn/unitgen/FixedRateMonoWriter.java
index 4dd9f2a..c215c55 100644
--- a/src/com/jsyn/unitgen/FixedRateMonoWriter.java
+++ b/src/com/jsyn/unitgen/FixedRateMonoWriter.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -21,11 +21,14 @@ import com.jsyn.ports.UnitInputPort;
 /**
  * Simple sample writer. Write one sample per audio frame with no interpolation. This can be used to
  * record audio or to build delay lines.
- * 
+ *
+ * Note that you must call start() on this unit because it does not have an output for pulling data.
+ *
  * @see FixedRateStereoWriter
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
 public class FixedRateMonoWriter extends SequentialDataWriter {
+
     public FixedRateMonoWriter() {
         addPort(input = new UnitInputPort("Input"));
     }
diff --git a/src/com/jsyn/unitgen/FixedRateStereoWriter.java b/src/com/jsyn/unitgen/FixedRateStereoWriter.java
index 9f4e38d..e4502f9 100644
--- a/src/com/jsyn/unitgen/FixedRateStereoWriter.java
+++ b/src/com/jsyn/unitgen/FixedRateStereoWriter.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -21,7 +21,9 @@ import com.jsyn.ports.UnitInputPort;
 /**
  * Simple stereo sample writer. Write two samples per audio frame with no interpolation. This can be
  * used to record audio or to build delay lines.
- * 
+ *
+ * Note that you must call start() on this unit because it does not have an output for pulling data.
+ *
  * @see FixedRateMonoWriter
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
diff --git a/src/com/jsyn/unitgen/LineOut.java b/src/com/jsyn/unitgen/LineOut.java
index d58f211..29c8ce7 100644
--- a/src/com/jsyn/unitgen/LineOut.java
+++ b/src/com/jsyn/unitgen/LineOut.java
@@ -42,6 +42,14 @@ public class LineOut extends UnitGenerator implements UnitSink {
         }
     }
 
+    /**
+     * This unit won't do anything unless you start() it.
+     */
+    @Override
+    public boolean isStartRequired() {
+        return true;
+    }
+
     @Override
     public UnitInputPort getInput() {
         return input;
diff --git a/src/com/jsyn/unitgen/MonoStreamWriter.java b/src/com/jsyn/unitgen/MonoStreamWriter.java
index 0184766..283af81 100644
--- a/src/com/jsyn/unitgen/MonoStreamWriter.java
+++ b/src/com/jsyn/unitgen/MonoStreamWriter.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -23,7 +23,9 @@ import com.jsyn.ports.UnitInputPort;
 
 /**
  * Write one sample per audio frame to an AudioOutputStream with no interpolation.
- * 
+ *
+ * Note that you must call start() on this unit because it does not have an output for pulling data.
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
 public class MonoStreamWriter extends UnitStreamWriter {
diff --git a/src/com/jsyn/unitgen/SequentialDataWriter.java b/src/com/jsyn/unitgen/SequentialDataWriter.java
index 5a5febb..cb3bb11 100644
--- a/src/com/jsyn/unitgen/SequentialDataWriter.java
+++ b/src/com/jsyn/unitgen/SequentialDataWriter.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -21,7 +21,9 @@ import com.jsyn.ports.UnitInputPort;
 
 /**
  * Base class for writing to a sample.
- * 
+ *
+ * Note that you must call start() on subclasses of this unit because it does not have an output for pulling data.
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
 public abstract class SequentialDataWriter extends UnitGenerator {
@@ -31,4 +33,12 @@ public abstract class SequentialDataWriter extends UnitGenerator {
     public SequentialDataWriter() {
         addPort(dataQueue = new UnitDataQueuePort("Data"));
     }
+
+    /**
+     * This unit won't do anything unless you start() it.
+     */
+    @Override
+    public boolean isStartRequired() {
+        return true;
+    }
 }
diff --git a/src/com/jsyn/unitgen/StereoStreamWriter.java b/src/com/jsyn/unitgen/StereoStreamWriter.java
index 072974b..b387836 100644
--- a/src/com/jsyn/unitgen/StereoStreamWriter.java
+++ b/src/com/jsyn/unitgen/StereoStreamWriter.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -23,7 +23,9 @@ import com.jsyn.ports.UnitInputPort;
 
 /**
  * Write two samples per audio frame to an AudioOutputStream as interleaved samples.
- * 
+ *
+ * Note that you must call start() on this unit because it does not have an output for pulling data.
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
 public class StereoStreamWriter extends UnitStreamWriter {
@@ -48,5 +50,4 @@ public class StereoStreamWriter extends UnitStreamWriter {
             }
         }
     }
-
 }
diff --git a/src/com/jsyn/unitgen/UnitGenerator.java b/src/com/jsyn/unitgen/UnitGenerator.java
index f8278ae..1e87ae6 100644
--- a/src/com/jsyn/unitgen/UnitGenerator.java
+++ b/src/com/jsyn/unitgen/UnitGenerator.java
@@ -59,8 +59,6 @@ public abstract class UnitGenerator {
     private boolean enabled = true;
     private static int nextId;
     private final int id = nextId++;
-    private int frameRate;
-    private double framePeriod;
 
     static Logger logger = Logger.getLogger(UnitGenerator.class.getName());
 
@@ -245,6 +243,16 @@ public abstract class UnitGenerator {
     }
 
     /**
+     * Some units, for example LineOut and FixedRateMonoWriter, will only work if
+     * started explicitly. Other units will run when downstream units are started.
+     *
+     * @return true if you should call start() for this unit
+     */
+    public boolean isStartRequired() {
+        return false;
+    }
+
+    /**
      * Start executing this unit directly by adding it to a "run list" of units in the synthesis
      * engine. This method is normally only called for the final unit in a chain, for example a
      * LineOut. When that final unit executes it will "pull" data from any units connected to its
@@ -310,8 +318,6 @@ public abstract class UnitGenerator {
      */
     @Deprecated
     public void setFrameRate(int rate) {
-        this.frameRate = rate;
-        this.framePeriod = 1.0 / rate;
     }
 
     /** Needed by UnitSink */
diff --git a/src/com/jsyn/unitgen/UnitStreamWriter.java b/src/com/jsyn/unitgen/UnitStreamWriter.java
index ecc231d..0c5bd8b 100644
--- a/src/com/jsyn/unitgen/UnitStreamWriter.java
+++ b/src/com/jsyn/unitgen/UnitStreamWriter.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -21,7 +21,9 @@ import com.jsyn.ports.UnitInputPort;
 
 /**
  * Base class for writing to an AudioOutputStream.
- * 
+ *
+ * Note that you must call start() on subclasses of this unit because it does not have an output for pulling data.
+ *
  * @author Phil Burk (C) 2009 Mobileer Inc
  */
 public abstract class UnitStreamWriter extends UnitGenerator implements UnitSink {
@@ -36,6 +38,14 @@ public abstract class UnitStreamWriter extends UnitGenerator implements UnitSink
         this.outputStream = outputStream;
     }
 
+    /**
+     * This unit won't do anything unless you start() it.
+     */
+    @Override
+    public boolean isStartRequired() {
+        return true;
+    }
+
     @Override
     public UnitInputPort getInput() {
         return input;
diff --git a/src/com/jsyn/util/MultiChannelSynthesizer.java b/src/com/jsyn/util/MultiChannelSynthesizer.java
index c2d0e86..6db0790 100644
--- a/src/com/jsyn/util/MultiChannelSynthesizer.java
+++ b/src/com/jsyn/util/MultiChannelSynthesizer.java
@@ -22,9 +22,9 @@ import com.jsyn.midi.MidiConstants;
 import com.jsyn.ports.UnitInputPort;
 import com.jsyn.ports.UnitOutputPort;
 import com.jsyn.unitgen.ExponentialRamp;
+import com.jsyn.unitgen.LinearRamp;
 import com.jsyn.unitgen.Multiply;
 import com.jsyn.unitgen.Pan;
-import com.jsyn.unitgen.LinearRamp;
 import com.jsyn.unitgen.PowerOfTwo;
 import com.jsyn.unitgen.SineOscillator;
 import com.jsyn.unitgen.TwoInDualOut;
@@ -53,10 +53,27 @@ public class MultiChannelSynthesizer {
     private TwoInDualOut outputUnit;
     private ChannelContext[] channels;
 
-    private class ChannelContext {
+    private class ChannelGroupContext {
         private VoiceDescription voiceDescription;
         private UnitVoice[] voices;
         private VoiceAllocator allocator;
+
+        ChannelGroupContext(int numVoices, VoiceDescription voiceDescription) {
+            this.voiceDescription = voiceDescription;
+
+            voices = new UnitVoice[numVoices];
+            for (int i = 0; i < numVoices; i++) {
+                UnitVoice voice = voiceDescription.createUnitVoice();
+                UnitGenerator ugen = voice.getUnitGenerator();
+                synth.add(ugen);
+                voices[i] = voice;
+
+            }
+            allocator = new VoiceAllocator(voices);
+        }
+    }
+
+    private class ChannelContext {
         private UnitOscillator lfo;
         private PowerOfTwo pitchToLinear;
         private LinearRamp timbreRamp;
@@ -65,12 +82,20 @@ public class MultiChannelSynthesizer {
         private Multiply volumeMultiplier;
         private Pan panner;
         private double vibratoRate = 5.0;
-        private double bendRangeOctaves = 24.0 / 12.0;
+        private double bendRangeOctaves = 2.0 / 12.0;
 //        private double bendRangeOctaves = 0.0 / 12.0;
         private int presetIndex;
+        private ChannelGroupContext groupContext;
+        VoiceOperation voiceOperation = new VoiceOperation() {
+            @Override
+            public void operate (UnitVoice voice) {
+                voice.usePreset(presetIndex);
+                connectVoice(voice);
+            }
+        };
 
-        void setup(int numVoices, VoiceDescription voiceDescription) {
-            this.voiceDescription = voiceDescription;
+        void setup(ChannelGroupContext groupContext) {
+            this.groupContext = groupContext;
             synth.add(pitchToLinear = new PowerOfTwo());
             synth.add(lfo = new SineOscillator()); // TODO use a MorphingOscillator or switch
                                                    // between S&H etc.
@@ -91,60 +116,57 @@ public class MultiChannelSynthesizer {
             lfo.amplitude.set(0.0);
             lfo.frequency.set(vibratoRate);
 
-            voices = new UnitVoice[numVoices];
-            for (int i = 0; i < numVoices; i++) {
-                UnitVoice voice = voiceDescription.createUnitVoice();
-                UnitGenerator ugen = voice.getUnitGenerator();
-                synth.add(ugen);
-
-                // Hook up some channel controllers to standard ports on the voice.
-                UnitInputPort freqMod = (UnitInputPort) ugen
-                        .getPortByName(UnitGenerator.PORT_NAME_FREQUENCY_SCALER);
-                if (freqMod != null) {
-                    pitchToLinear.output.connect(freqMod);
-                }
-                UnitInputPort timbrePort = (UnitInputPort) ugen
-                        .getPortByName(UnitGenerator.PORT_NAME_TIMBRE);
-                if (timbrePort != null) {
-                    timbreRamp.output.connect(timbrePort);
-                    timbreRamp.input.setup(timbrePort);
-                }
-                UnitInputPort pressurePort = (UnitInputPort) ugen
-                        .getPortByName(UnitGenerator.PORT_NAME_PRESSURE);
-                if (pressurePort != null) {
-                    pressureRamp.output.connect(pressurePort);
-                    pressureRamp.input.setup(pressurePort);
-                }
-                voice.getOutput().connect(volumeMultiplier.inputA); // mono mix all the voices
-                voices[i] = voice;
-            }
-
             volumeRamp.output.connect(volumeMultiplier.inputB);
             volumeMultiplier.output.connect(panner.input);
             panner.output.connect(0, outputUnit.inputA, 0); // Use MultiPassthrough
             panner.output.connect(1, outputUnit.inputB, 0);
 
-            allocator = new VoiceAllocator(voices);
+        }
+
+        private void connectVoice(UnitVoice voice) {
+            UnitGenerator ugen = voice.getUnitGenerator();
+            // Hook up some channel controllers to standard ports on the voice.
+            UnitInputPort freqMod = (UnitInputPort) ugen
+                    .getPortByName(UnitGenerator.PORT_NAME_FREQUENCY_SCALER);
+            if (freqMod != null) {
+                freqMod.disconnectAll();
+                pitchToLinear.output.connect(freqMod);
+            }
+            UnitInputPort timbrePort = (UnitInputPort) ugen
+                    .getPortByName(UnitGenerator.PORT_NAME_TIMBRE);
+            if (timbrePort != null) {
+                timbrePort.disconnectAll();
+                timbreRamp.output.connect(timbrePort);
+                timbreRamp.input.setup(timbrePort);
+            }
+            UnitInputPort pressurePort = (UnitInputPort) ugen
+                    .getPortByName(UnitGenerator.PORT_NAME_PRESSURE);
+            if (pressurePort != null) {
+                pressurePort.disconnectAll();
+                pressureRamp.output.connect(pressurePort);
+                pressureRamp.input.setup(pressurePort);
+            }
+            voice.getOutput().disconnectAll();
+            voice.getOutput().connect(volumeMultiplier.inputA); // mono mix all the voices
         }
 
         void programChange(int program) {
-            int programWrapped = program % voiceDescription.getPresetCount();
-            String name = voiceDescription.getPresetNames()[programWrapped];
-            System.out.println("Preset[" + program + "] = " + name);
+            int programWrapped = program % groupContext.voiceDescription.getPresetCount();
+            String name = groupContext.voiceDescription.getPresetNames()[programWrapped];
+            //System.out.println("Preset[" + program + "] = " + name);
             presetIndex = programWrapped;
         }
 
         void noteOff(int noteNumber, int velocity) {
-            allocator.noteOff(noteNumber, synth.createTimeStamp());
+            groupContext.allocator.noteOff(noteNumber, synth.createTimeStamp());
         }
 
         void noteOn(int noteNumber, int velocity) {
             double frequency = AudioMath.pitchToFrequency(noteNumber);
             double amplitude = velocity / (4 * 128.0);
             TimeStamp timeStamp = synth.createTimeStamp();
-            allocator.usePreset(presetIndex, timeStamp);
-            // System.out.println("noteOn(noteNumber) -> " + frequency + " Hz");
-            allocator.noteOn(noteNumber, frequency, amplitude, timeStamp);
+            //System.out.println("noteOn(noteNumber) -> " + frequency + " Hz");
+            groupContext.allocator.noteOn(noteNumber, frequency, amplitude, voiceOperation, timeStamp);
         }
 
         public void setPitchBend(double offset) {
@@ -223,8 +245,10 @@ public class MultiChannelSynthesizer {
         if (outputUnit == null) {
             synth.add(outputUnit = new TwoInDualOut());
         }
+        ChannelGroupContext groupContext = new ChannelGroupContext(voicesPerChannel,
+                voiceDescription);
         for (int i = 0; i < numChannels; i++) {
-            channels[startChannel + i].setup(voicesPerChannel, voiceDescription);
+            channels[startChannel + i].setup(groupContext);
         }
     }
 
@@ -250,6 +274,7 @@ public class MultiChannelSynthesizer {
      * @param offset ranges from -1.0 to +1.0
      */
     public void setPitchBend(int channel, double offset) {
+        //System.out.println("setPitchBend[" + channel + "] = " + offset);
         ChannelContext channelContext = channels[channel];
         channelContext.setPitchBend(offset);
     }
@@ -289,7 +314,7 @@ public class MultiChannelSynthesizer {
      * Pan from left to right.
      *
      * @param channel
-     * @param offset ranges from -1.0 to +1.0
+     * @param pan ranges from -1.0 to +1.0
      */
     public void setPan(int channel, double pan) {
         ChannelContext channelContext = channels[channel];
diff --git a/tests/com/jsyn/examples/LongEcho.java b/tests/com/jsyn/examples/LongEcho.java
index 41f21f2..0a86efd 100644
--- a/tests/com/jsyn/examples/LongEcho.java
+++ b/tests/com/jsyn/examples/LongEcho.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *     http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -33,7 +33,7 @@ import com.jsyn.util.WaveFileWriter;
 
 /**
  * Echo the input using a circular buffer in a sample.
- * 
+ *
  * @author Phil Burk (C) 2010 Mobileer Inc
  */
 public class LongEcho {
@@ -50,9 +50,7 @@ public class LongEcho {
     private void test() throws IOException {
         // Create a context for the synthesizer.
         synth = JSyn.createSynthesizer();
-        // Add a tone generator.
         synth.add(channelIn = new ChannelIn());
-        // Add an output mixer.
         synth.add(channelOut = new ChannelOut());
 
         synth.add(minner = new Minimum());
diff --git a/tests/com/jsyn/examples/PlayGrains.java b/tests/com/jsyn/examples/PlayGrains.java
index fd71e68..b9a7b5b 100644
--- a/tests/com/jsyn/examples/PlayGrains.java
+++ b/tests/com/jsyn/examples/PlayGrains.java
@@ -57,14 +57,12 @@ public class PlayGrains extends JApplet {
     private static final int NUM_GRAINS = 32;
     private FloatSample sample;
     private WaveRecorder recorder;
-
-    private static final boolean useSample = false;
     private final static boolean useRecorder = false;
 
-    // File sampleFile = new File( "samples/instructions.wav" );
-    File sampleFile = new File(
-    // "/Users/phil/Work/jsyn/guitar100/Guitar100_Ocean_1#02.aif" );
-            "/Users/phil/Music/samples/ChewyMonkeysWhistle.aiff");
+    private static final boolean useSample = false;
+    // If you enable useSample then you will need to replace the file name below with a valid
+    // file name on your computer.
+    private File sampleFile = new File("/Users/phil/Music/samples/ChewyMonkeysWhistle.aiff");
 
     /* Can be run as either an application or as an applet. */
     public static void main(String args[]) {
@@ -173,8 +171,6 @@ public class PlayGrains extends JApplet {
 
             // Start synthesizer using default stereo output at 44100 Hz.
             synth.start();
-            // Start lineOut so it can pull data from other units.
-            lineOut.start();
 
             if (useRecorder) {
                 grainFarm.output.connect(0, recorder.getInput(), 0);