您如何播放长音频剪辑？

您如何播放长音频剪辑？

使用

BigClip

。这是我玩12-18分钟（或更多1分钟）的MP3的课堂。

它要求

mp3plugin.jar

在运行时类路径上实际加载MP3格式的声音，但这不是重点。重点是：

1. BigClip

   会将声音文件加载到JVM之前允许的最大内存中

   OutOfMemoryError

   。

---

import java.awt.Component;import javax.swing.*;import javax.sound.sampled.*;import java.io.*;import java.util.logging.*;import java.util.Arrays;import java.net.URL;import javax.swing.JOptionPane;class BigClipExample {    public static void main(String[] args) throws Exception {        URL url = new URL("http://pspre.org/media/leftright.wav");        BigClip clip = new BigClip();        AudioInputStream ais = AudioSystem.getAudioInputStream(url);        clip.open(ais);        clip.start();        JOptionPane.showMessageDialog(null, "BigClip.start()");        clip.loop(4);        JOptionPane.showMessageDialog(null, "BigClip.loop(4)");        clip.setFastForward(true);        clip.loop(8);        // the looping/FF combo. reveals a bug..        // there is a slight 'click' in the sound that should not be audible        JOptionPane.showMessageDialog(null, "Are you on speed?");    }}class BigClip implements Clip, LineListener {        private SourceDataLine dataLine;        private byte[] audioData;        private ByteArrayInputStream inputStream;        private int loopCount = 1;        private int countDown = 1;        private int loopPointStart;        private int loopPointEnd;        private int framePosition;        private Thread thread;        private boolean active;        private long timelastPositionSet;    private int bufferUpdateFactor = 2;        Component parent = null;        private Logger logger = Logger.getAnonymousLogger();        public BigClip() {}        public BigClip(Clip clip) throws LineUnavailableException {        dataLine = AudioSystem.getSourceDataLine( clip.getFormat() );    }        public byte[] getAudioData() {        return audioData;    }        public void setParentComponent(Component parent) {        this.parent = parent;    }        private long convertframesToMilliseconds(int frames) {        return (frames/(long)dataLine.getFormat().getSampleRate())*1000;    }        private int convertMillisecondsToframes(long milliseconds) {        return (int)(milliseconds/dataLine.getFormat().getSampleRate());    }    @Override    public void update(LineEvent le) {        logger.log(Level.FINEST, "update: " + le );    }    @Override    public void loop(int count) {        logger.log(Level.FINEST, "loop(" + count + ") - framePosition: " + framePosition);        loopCount = count;        countDown = count;        active = true;        inputStream.reset();        start();    }    @Override    public void setLoopPoints(int start, int end) {        if ( start<0 || start>audioData.length-1 || end<0 || end>audioData.length ) { throw new IllegalArgumentException(     "Loop points '" +     start +     "' and '" +     end +     "' cannot be set for buffer of size " +     audioData.length);        }        if (start>end) { throw new IllegalArgumentException(     "End position " +     end +     " preceeds start position " + start);        }        loopPointStart = start;        framePosition = loopPointStart;        loopPointEnd = end;    }    @Override    public void setMicrosecondPosition(long milliseconds) {        framePosition = convertMillisecondsToframes(milliseconds);    }    @Override    public long getMicrosecondPosition() {        return convertframesToMilliseconds(getframePosition());    }    @Override    public long getMicrosecondLength() {        return convertframesToMilliseconds(getframeLength());    }    @Override    public void setframePosition(int frames) {        framePosition = frames;        int offset = framePosition*format.getframeSize();        try { inputStream.reset(); inputStream.read(new byte[offset]);        } catch(Exception e) { e.printStackTrace();        }    }    @Override    public int getframePosition() {        long timeSinceLastPositionSet = System.currentTimeMillis() - timelastPositionSet;        int size = dataLine.getBufferSize()*(format.getChannels()/2)/bufferUpdateFactor;        int framesSinceLast = (int)((timeSinceLastPositionSet/1000f)* dataLine.getFormat().getframeRate());        int framesRemainingTillTime = size - framesSinceLast;        return framePosition - framesRemainingTillTime;    }    @Override    public int getframeLength() {        return audioData.length/format.getframeSize();    }    AudioFormat format;    @Override    public void open(AudioInputStream stream) throws        IOException,        LineUnavailableException {        AudioInputStream is1;        format = stream.getFormat();        if (format.getEncoding()!=AudioFormat.Encoding.PCM_SIGNED) { is1 = AudioSystem.getAudioInputStream(     AudioFormat.Encoding.PCM_SIGNED, stream );        } else { is1 = stream;        }        format = is1.getFormat();        InputStream is2;        if (parent!=null) { ProgressMonitorInputStream pmis = new ProgressMonitorInputStream(     parent,     "Loading track..",     is1); pmis.getProgressMonitor().setMillisToPopup(0); is2 = pmis;        } else { is2 = is1;        }        byte[] buf = new byte[ 2^16 ];        int totalRead = 0;        int numRead = 0;        ByteArrayOutputStream baos = new ByteArrayOutputStream();        numRead = is2.read( buf );        while (numRead>-1) { baos.write( buf, 0, numRead ); numRead = is2.read( buf, 0, buf.length ); totalRead += numRead;        }        is2.close();        audioData = baos.toByteArray();        AudioFormat afTemp;        if (format.getChannels()<2) { afTemp = new AudioFormat(     format.getEncoding(),     format.getSampleRate(),     format.getSampleSizeInBits(),     2,     format.getSampleSizeInBits()*2/8, // calculate frame size     format.getframeRate(),     format.isBigEndian()     );        } else { afTemp = format;        }        setLoopPoints(0,audioData.length);        dataLine = AudioSystem.getSourceDataLine(afTemp);        dataLine.open();        inputStream = new ByteArrayInputStream( audioData );    }    @Override    public void open(AudioFormat format,        byte[] data,        int offset,        int bufferSize)        throws LineUnavailableException {        byte[] input = new byte[bufferSize];        for (int ii=0; ii<input.length; ii++) { input[ii] = data[offset+ii];        }        ByteArrayInputStream inputStream = new ByteArrayInputStream(input);        try { AudioInputStream ais1 = AudioSystem.getAudioInputStream(inputStream); AudioInputStream ais2 = AudioSystem.getAudioInputStream(format, ais1); open(ais2);        } catch( UnsupportedAudioFileException uafe ) { throw new IllegalArgumentException(uafe);        } catch( IOException ioe ) { throw new IllegalArgumentException(ioe);        }        // TODO    -    throw IAE for invalid frame size, format.    }    @Override    public float getLevel() {        return dataLine.getLevel();    }    @Override    public long getLongframePosition() {        return dataLine.getLongframePosition()*2/format.getChannels();    }    @Override    public int available() {        return dataLine.available();    }    @Override    public int getBufferSize() {        return dataLine.getBufferSize();    }    @Override    public AudioFormat getFormat() {        return format;    }    @Override    public boolean isActive() {        return dataLine.isActive();    }    @Override    public boolean isRunning() {        return dataLine.isRunning();    }    @Override    public boolean isOpen() {        return dataLine.isOpen();    }    @Override    public void stop() {        logger.log(Level.FINEST, "BigClip.stop()");        active = false;        // why did I have this commented out?        dataLine.stop();        if (thread!=null) { try {     active = false;     thread.join(); } catch(InterruptedException wakeAndContinue) { }        }    }    public byte[] convertMonoToStereo(byte[] data, int bytesRead) {        byte[] tempData = new byte[bytesRead*2];        if (format.getSampleSizeInBits()==8) { for(int ii=0; ii<bytesRead; ii++) {     byte b = data[ii];     tempData[ii*2] = b;     tempData[ii*2+1] = b; }        } else { for(int ii=0; ii<bytesRead-1; ii+=2) {     //byte b2 = is2.read();     byte b1 = data[ii];     byte b2 = data[ii+1];     tempData[ii*2] = b1;     tempData[ii*2+1] = b2;     tempData[ii*2+2] = b1;     tempData[ii*2+3] = b2; }        }        return tempData;    }    boolean fastForward;    boolean fastRewind;    public void setFastForward(boolean fastForward) {        logger.log(Level.FINEST, "FastForward " + fastForward);        this.fastForward = fastForward;        fastRewind = false;        flush();    }    public boolean getFastForward() {        return fastForward;    }    public void setFastRewind(boolean fastRewind) {        logger.log(Level.FINEST, "FastRewind " + fastRewind);        this.fastRewind = fastRewind;        fastForward = false;        flush();    }    public boolean getFastRewind() {        return fastRewind;    }        @Override    public void start() {        Runnable r = new Runnable() { public void run() {     try {                  dataLine.open();         dataLine.start();         active = true;         int bytesRead = 0;         int frameSize = dataLine.getFormat().getframeSize();         int bufSize = dataLine.getBufferSize();         boolean startOrMove = true;         byte[] data = new byte[bufSize];         int offset = framePosition*frameSize;         int totalBytes = offset;         bytesRead = inputStream.read(new byte[offset], 0, offset);         logger.log(Level.FINE, "bytesRead " + bytesRead );         bytesRead = inputStream.read(data,0,data.length);         logger.log(Level.FINE, "loopCount " + loopCount );         logger.log(Level.FINE, "countDown " + countDown );         logger.log(Level.FINE, "bytesRead " + bytesRead );         while (bytesRead != -1 &&  (loopCount==Clip.LOOP_ConTINUOUSLY ||  countDown>0) &&  active ) {  logger.log(Level.FINEST,      "BigClip.start() loop " + framePosition );  totalBytes += bytesRead;  int framesRead;  byte[] tempData;  if (format.getChannels()<2) {      tempData = convertMonoToStereo(data, bytesRead);      framesRead = bytesRead/          format.getframeSize();      bytesRead*=2;  } else {      framesRead = bytesRead/          dataLine.getFormat().getframeSize();      tempData = Arrays.copyOfRange(data, 0, bytesRead);  }  framePosition += framesRead;  if (framePosition>=loopPointEnd) {      framePosition = loopPointStart;      inputStream.reset();      countDown--;      logger.log(Level.FINEST,          "Loop Count: " + countDown );  }  timelastPositionSet = System.currentTimeMillis();  byte[] newData;  if (fastForward) {      newData = getEveryNthframe(tempData, 2);  } else if (fastRewind) {      byte[] temp = getEveryNthframe(tempData, 2);      newData = reverseframes(temp);      inputStream.reset();      totalBytes -= 2*bytesRead;  framePosition -= 2*framesRead;      if (totalBytes<0) {          setFastRewind(false);          totalBytes = 0;      }      inputStream.skip(totalBytes);      logger.log(Level.FINE, "totalBytes " + totalBytes);  } else {      newData = tempData;  }  dataLine.write(newData, 0, newData.length);  if (startOrMove) {      data = new byte[bufSize/          bufferUpdateFactor];      startOrMove = false;  }  bytesRead = inputStream.read(data,0,data.length);  if (bytesRead<0 && countDown-->1) {      inputStream.read(new byte[offset], 0, offset);      logger.log(Level.FINE, "loopCount " + loopCount );      logger.log(Level.FINE, "countDown " + countDown );      inputStream.reset();      bytesRead = inputStream.read(data,0,data.length);  }         }         logger.log(Level.FINEST,  "BigClip.start() loop ENDED" + framePosition );         active = false;         countDown = 1;         framePosition = 0;         inputStream.reset();         dataLine.drain();         dataLine.stop();                  dataLine.close();     } catch (LineUnavailableException lue) {         logger.log( Level.SEVERE,  "No sound line available!", lue );         if (parent!=null) {  JOptionPane.showMessageDialog(      parent,      "Clear the sound lines to proceed",      "No audio lines available!",      JOptionPane.ERROR_MESSAGE);         }     } }        };        thread= new Thread(r);        // makes thread behaviour compatible with JavaSound post 1.4        thread.setDaemon(true);        thread.start();    }        public byte[] reverseframes(byte[] data) {        byte[] reversed = new byte[data.length];        byte[] frame = new byte[4];        for (int ii=0; ii<data.length/4; ii++) { int first = (data.length)-((ii+1)*4)+0; int last = (data.length)-((ii+1)*4)+3; frame[0] = data[first]; frame[1] = data[(data.length)-((ii+1)*4)+1]; frame[2] = data[(data.length)-((ii+1)*4)+2]; frame[3] = data[last]; reversed[ii*4+0] = frame[0]; reversed[ii*4+1] = frame[1]; reversed[ii*4+2] = frame[2]; reversed[ii*4+3] = frame[3]; if (ii<5 || ii>(data.length/4)-5) {     logger.log(Level.FINER, "From t" + first + " tlast " + last );     logger.log(Level.FINER, "To t" + ((ii*4)+0) + " tlast " + ((ii*4)+3) ); }        }        return reversed;    }        public byte[] getEveryNthframe(byte[] data, int skip) {        int length = data.length/skip;        length = (length/4)*4;        logger.log(Level.FINEST, "length " + data.length + " t" + length);        byte[] b = new byte[length];        //byte[] frame = new byte[4];        for (int ii=0; ii<b.length/4; ii++) { b[ii*4+0] = data[ii*skip*4+0]; b[ii*4+1] = data[ii*skip*4+1]; b[ii*4+2] = data[ii*skip*4+2]; b[ii*4+3] = data[ii*skip*4+3];        }        return b;    }    @Override    public void flush() {        dataLine.flush();    }    @Override    public void drain() {        dataLine.drain();    }    @Override    public void removeLineListener(LineListener listener) {        dataLine.removeLineListener(listener);    }    @Override    public void addLineListener(LineListener listener) {        dataLine.addLineListener(listener);    }    @Override    public Control getControl(Control.Type control) {        return dataLine.getControl(control);    }    @Override    public Control[] getControls() {        if (dataLine==null) { return new Control[0];        } else { return dataLine.getControls();        }    }    @Override    public boolean isControlSupported(Control.Type control) {        return dataLine.isControlSupported(control);    }    @Override    public void close() {        dataLine.close();    }    @Override    public void open() throws LineUnavailableException {        throw new IllegalArgumentException("illegal call to open() in interface Clip");    }    @Override    public Line.Info getLineInfo() {        return dataLine.getLineInfo();    }        public double getLargestSampleSize() {        int largest = 0;        int current;        boolean signed = (format.getEncoding()==AudioFormat.Encoding.PCM_SIGNED);        int bitDepth = format.getSampleSizeInBits();        boolean bigEndian = format.isBigEndian();        int samples = audioData.length*8/bitDepth;        if (signed) { if (bitDepth/8==2) {     if (bigEndian) {         for (int cc = 0; cc < samples; cc++) {  current = (audioData[cc*2]*256 + (audioData[cc*2+1] & 0xFF));  if (Math.abs(current)>largest) {      largest = Math.abs(current);  }         }     } else {         for (int cc = 0; cc < samples; cc++) {  current = (audioData[cc*2+1]*256 + (audioData[cc*2] & 0xFF));  if (Math.abs(current)>largest) {      largest = Math.abs(current);  }         }     } } else {     for (int cc = 0; cc < samples; cc++) {         current = (audioData[cc] & 0xFF);         if (Math.abs(current)>largest) {  largest = Math.abs(current);         }     } }        } else { if (bitDepth/8==2) {     if (bigEndian) {         for (int cc = 0; cc < samples; cc++) {  current = (audioData[cc*2]*256 + (audioData[cc*2+1] - 0x80));  if (Math.abs(current)>largest) {      largest = Math.abs(current);  }         }     } else {         for (int cc = 0; cc < samples; cc++) {  current = (audioData[cc*2+1]*256 + (audioData[cc*2] - 0x80));  if (Math.abs(current)>largest) {      largest = Math.abs(current);  }         }     } } else {     for (int cc = 0; cc < samples; cc++) {         if ( audioData[cc]>0 ) {  current = (audioData[cc] - 0x80);  if (Math.abs(current)>largest) {      largest = Math.abs(current);  }         } else {  current = (audioData[cc] + 0x80);  if (Math.abs(current)>largest) {      largest = Math.abs(current);  }         }     } }        }        // audioData        logger.log(Level.FINEST, "Max signal level: " + (double)largest/(Math.pow(2, bitDepth-1)));        return (double)largest/(Math.pow(2, bitDepth-1));    }}