Hi all,
I’m developing audio mixer to play audio (wave files) and to have control on it.
I’m able to play and stop the audio with AudioInputStream and SourceDataLine. But unable to pause and resume the playing/running audio file. 
Can any on help me how to get the control on audio file like pause, resume and forward/rewind (5sec, 10sec,…). :-[ .
I’m attaching the code, which I’m using for my application.
/*
* Created on Aug 5, 2005
*/
package Samples.audio;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.SourceDataLine;
import javax.sound.sampled.UnsupportedAudioFileException;
import javax.sound.sampled.FloatControl;
/**
* @author vinesh
*/
public class FoundationAudioStream
implements Runnable{
// better size
private static final int EXTERNAL_BUFFER_SIZE = 4000 * 4;
private Thread m_thread = null;
private Object m_dataSource;
private AudioInputStream m_audioInputStream;
private SourceDataLine m_sourceDataLine;
public static long lastMicrosecondPosition=0;
public static long currentMicrosecondPosition=0;
private boolean pauseFlag=false;
private int pauseCount;
private int bufferSize;
private int audioLength; // Length of the sound.
public static int audioPosition = 0; // Current position within the sound
/** This variable is used to distinguish stopped state from paused state. */
private boolean m_bRunning;
protected FoundationAudioStream()
{
m_dataSource = null;
m_audioInputStream = null;
m_sourceDataLine = null;
m_gainControl = null;
m_panControl = null;
}
protected void setDataSource(File file)
throws UnsupportedAudioFileException, LineUnavailableException, IOException
{
m_dataSource = file;
initAudioInputStream();
}
private void initAudioInputStream()
throws UnsupportedAudioFileException, LineUnavailableException, IOException{
if (m_dataSource instanceof File)initAudioInputStream((File) m_dataSource);
}
private void initAudioInputStream(File file)
throws UnsupportedAudioFileException, IOException{
m_audioInputStream = AudioSystem.getAudioInputStream(file);
bufferSize = (int)file.length();
}
protected void initLine()
throws LineUnavailableException{
if (m_sourceDataLine == null){
createLine();
openLine();
}else{
AudioFormat lineAudioFormat = m_sourceDataLine.getFormat();
AudioFormat audioInputStreamFormat = m_audioInputStream == null ? null : m_audioInputStream.getFormat();
if (!lineAudioFormat.equals(audioInputStreamFormat)){
m_sourceDataLine.close();
openLine();
}
}
}
private void createLine()
throws LineUnavailableException{
if (m_sourceDataLine != null)return;
AudioFormat audioFormat = m_audioInputStream.getFormat();
DataLine.Info info =
new DataLine.Info(SourceDataLine.class, audioFormat, AudioSystem.NOT_SPECIFIED);
m_sourceDataLine = (SourceDataLine) AudioSystem.getLine(info);
/** reseting the lastMicrosecondPosition for progress bar. */
lastMicrosecondPosition=0;
}
private void openLine()
throws LineUnavailableException{
if (m_sourceDataLine == null)return;
AudioFormat audioFormat = m_audioInputStream.getFormat();
m_sourceDataLine.open(audioFormat, m_sourceDataLine.getBufferSize());
}
/** Start the audio */
public void start()
{
if (!(m_thread == null || !m_thread.isAlive()))
out("WARNING: old thread still running!!");
m_thread = new Thread(this);
m_thread.start();
m_sourceDataLine.start();
}
/** Stop the audio. */
protected void stop()
{
if (m_bRunning)
{
if (m_sourceDataLine != null)
{
lastMicrosecondPosition=m_sourceDataLine.getMicrosecondPosition();
m_sourceDataLine.stop();
m_sourceDataLine.flush();
}
m_bRunning = false;
/** We re-initialize the AudioInputStream. */
try{
initAudioInputStream();
}catch (UnsupportedAudioFileException e){}
catch (LineUnavailableException e){}
catch (IOException e){}
}
}
/** Pause the audio */
public void pause(){
m_sourceDataLine.stop();}
/** Continue playing audio after pause */
public void resume(){
m_sourceDataLine.start();}
/** Stop playing the audio and reset the position to 0 on progress bar */
public void resetAudio( ) {
stop( );
audioPosition = 0;
TestAudioPlayer.songPerMillisecond.setValue(0);
}
public void run()
{
int nBytesRead = 0;
m_bRunning = true;
byte[] abData = new byte[EXTERNAL_BUFFER_SIZE];
int currentCount=0;
while (nBytesRead != -1 && m_bRunning)
{
try{
nBytesRead = m_audioInputStream.read(abData, 0, abData.length);
}catch (IOException e){
e.printStackTrace();}
if (nBytesRead >= 0 )
int nBytesWritten = m_sourceDataLine.write(abData, 0, nBytesRead);
}
/** for pause to lock the song played */
if(pauseFlag)pauseCount=currentCount;
m_sourceDataLine.drain();
stop();
/** Reset the progress bar position after audio is completed. */
lastMicrosecondPosition=m_sourceDataLine.getMicrosecondPosition();
if(!TestAudioPlayer.start.isEnabled())TestAudioPlayer.start.setEnabled(true);
if(!TestAudioPlayer.select.isEnabled())TestAudioPlayer.select.setEnabled(true);
}
private static void out(String strMessage){
System.out.println(strMessage);
}
}
When I call pause method the audio will stop playing, but when I call resume method the audio will drain and stop playing.
-vinesh
