srcjar/javajs/util/JSAudioThread.java

   1 package javajs.util;
   2
   3 import javax.sound.sampled.AudioFormat;
   4 import javax.sound.sampled.AudioSystem;
   5 import javax.sound.sampled.DataLine;
   6 import javax.sound.sampled.SourceDataLine;
   7
   8 import sun.audio.AudioData;
   9 import sun.audio.AudioDataStream;
  10 import sun.audio.AudioPlayer;
  11
  12
  13 /**
  14  * The JSAudioThread adds a layer to JSThread that is specific for audio.
  15  * This class utilizes JSAudioLine, which is not fully fleshed out.
  16  *
  17  * Two very simple interfaces,
  18  *
  19  * (new JSAudioThread()).playULawData(byte[] b);
  20  *
  21  * and
  22  *
  23  * (new JSAudioThread(audioFormat)).playOnce(byte[] b, offset, length);
  24  *
  25  * allow straightforward audio production without having to work with
  26  * SourceDataLine directly.
  27  *
  28  * As a JSThread, this class implements myInit(), isLooping(), myLoop(),
  29  * whenDone(), onException(), and doFinally().
  30  *
  31  * If the constructor JSAudioThread(JSAudioThreadUser, AudioFormat, byte[]) is
  32  * used, then the JSAudioThreadUser must simply implement fillAudioBuffer(),
  33  * checkSoundStatus(), and audioThreadExiting() for very simple streaming audio.
  34  * JSAudioThread will then take care of all the timing issues.
  35  *
  36  * But the implementer is welcome to override any of the JSThread overrides
  37  * themselves in order to customize this further.
  38  *
  39  * The standard streaming case, then is:
  40  *
  41  * audioThread = new JSAudioThread(audioUser, audioFormat, audioByteBuffer);
  42  * audioThread.start();
  43  *
  44  * where audioUser provides
  45  *
  46  * checkSoundStatus() (called in isLooping()),
  47  *
  48  * fillAudioBuffer() (called in myLoop()),
  49  *
  50  * and
  51  *
  52  * audioThreadExiting() (called in doFinally()).
  53  *
  54  * @author Bob Hanson
  55  *
  56  */
  57 public class JSAudioThread extends JSThread {
  58
  59         protected Owner owner;
  60         protected boolean done;
  61         protected int myBufferLength;
  62         protected SourceDataLine line;
  63         protected int rate, nChannels, bitsPerSample;
  64
  65         protected byte[] audioByteBuffer;
  66         protected int audioBufferByteLength;
  67
  68         private AudioFormat audioFormat;
  69         private int myBufferOffset;
  70         private int playCount;
  71
  72         public JSAudioThread(Owner owner, AudioFormat audioFormat, byte[] audioByteBuffer) {
  73                 this.owner = owner;
  74                 setFormat(audioFormat);
  75                 setBuffer(audioByteBuffer);
  76         }
  77
  78         /**
  79          * A convenience constructor requiring standard settings of
  80          * signed (for 8-bit) and littleEndian (for 16-bit)
  81          *
  82          * @param owner
  83          * @param rate
  84          * @param bitsPerSample
  85          * @param nChannels
  86          * @param audioByteBuffer
  87          */
  88         public JSAudioThread(Owner owner, int rate, int bitsPerSample, int nChannels, byte[] audioByteBuffer) {
  89                 this.owner = owner;
  90                 setFormat(new AudioFormat(rate, bitsPerSample, nChannels, true, false));
  91                 setBuffer(audioByteBuffer);
  92         }
  93
  94         /**
  95          * primarily available for (new JSAudioThread()).playULawData
  96          *
  97          */
  98         public JSAudioThread() {
  99         }
 100
 101         /**
 102          * primarily available for (new JSAudioThread()).playOnce
 103          *
 104          */
 105         public JSAudioThread(AudioFormat audioFormat) {
 106                 setFormat(audioFormat);
 107         }
 108
 109         /**
 110          *
 111          * A simple 8-bit uLaw data player
 112          *
 113          * @param data
 114          */
 115         public void playULawData(byte[] data) {
 116                 // this constructor uses default new AudioFormat(ULAW,8000,8,1,1,8000,true)
 117                 // threading is taken care of by the browser in JavaScript
 118                 AudioPlayer.player.start(new AudioDataStream(new AudioData(data)));
 119         }
 120
 121
 122         /**
 123          * Just play once through; no additions
 124          *
 125          * @param data
 126          */
 127         public void playOnce(byte[] data, int offset, int length) {
 128                 setBuffer(data);
 129                 myBufferOffset = offset;
 130                 myBufferLength = length;
 131                 playCount = 1;
 132                 start();
 133         }
 134
 135         public void setBuffer(byte[] audioByteBuffer) {
 136                 this.audioByteBuffer = audioByteBuffer;
 137                 audioBufferByteLength = audioByteBuffer.length;
 138         }
 139
 140         public SourceDataLine getLine() {
 141                 return line;
 142         }
 143
 144         public AudioFormat getFormat() {
 145                 return audioFormat;
 146         }
 147
 148         public void setFormat(AudioFormat audioFormat) {
 149                 this.audioFormat = audioFormat;
 150                 rate = (int) audioFormat.getSampleRate();
 151                 bitsPerSample = audioFormat.getSampleSizeInBits();
 152                 nChannels = audioFormat.getChannels();
 153         }
 154
 155         public void resetAudio() {
 156                 if (line == null)
 157                         return;
 158                 line.flush();
 159                 line.close();
 160                 line = null;
 161         }
 162
 163         /**
 164          * Standard initialization of a SourceDataLine
 165          *
 166          */
 167         @Override
 168         protected boolean myInit() {
 169                 try {
 170                         DataLine.Info info = new DataLine.Info(SourceDataLine.class, audioFormat);
 171                         if (line != null)
 172                                 line.close();
 173                         line = (SourceDataLine) AudioSystem.getLine(info);
 174                         line.open(audioFormat, audioBufferByteLength);
 175                         line.start();
 176                 } catch (Exception e) {
 177                         e.printStackTrace();
 178                         return false;
 179                 }
 180                 return true;
 181         }
 182
 183         @Override
 184         protected boolean isLooping() {
 185                 return !done && (--playCount >= 0 || owner != null && owner.checkSoundStatus());
 186         }
 187
 188         @Override
 189         protected boolean myLoop() {
 190                 if (!done) {
 191                         if ((myBufferLength = (owner == null ? myBufferLength : owner.fillAudioBuffer())) <= 0)
 192                                 return !(done = true);
 193                         try {
 194                                 if (line == null)
 195                                         myInit();
 196                                 line.write(audioByteBuffer, myBufferOffset, myBufferLength);
 197                         } catch (Exception e) {
 198                                 e.printStackTrace();
 199                                 done = true;
 200                         }
 201                 }
 202                 return !done;
 203         }
 204
 205         @Override
 206         protected void whenDone() {
 207                 done = true;
 208                 resetAudio();
 209         }
 210
 211         @Override
 212         protected int getDelayMillis() {
 213                 // about 25% of the actual play time
 214         return 1000                                        // ms/sec
 215                         * (myBufferLength  * 8 / bitsPerSample)        // * samples
 216                         / rate                                         // * seconds/sample)
 217                         / nChannels                                    // / number of channels
 218                         / 4;                                           // * 25%
 219         }
 220
 221         @Override
 222         protected void onException(Exception e) {
 223                 e.printStackTrace();
 224         }
 225
 226         @Override
 227         protected void doFinally() {
 228                 if (owner != null)
 229                         owner.audioThreadExiting();
 230         }
 231
 232         public interface Owner {
 233
 234                 /**
 235                  *
 236                  * @return true if thread should continue; false if not
 237                  *
 238                  */
 239                 boolean checkSoundStatus();
 240
 241                 /** fill audio buffer
 242                  *
 243                  * @return number of bytes to write to audio line
 244                  *
 245                  */
 246                 int fillAudioBuffer();
 247
 248                 /**
 249                  *  called from the finally clause when complete
 250                  *
 251                  */
 252                 void audioThreadExiting();
 253
 254
 255         }
 256
 257 }
 258