wave混音的实现（2）
关于混音算法，参考的是http://jacky-zhang.iteye.com/blog/766053，下面是具体的实现逻辑

package example.audio;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.InputStream;import javax.microedition.io.Connector;import javax.microedition.io.HttpConnection;import javax.microedition.io.file.FileConnection;import javax.microedition.lcdui.Command;import javax.microedition.lcdui.CommandListener;import javax.microedition.lcdui.Display;import javax.microedition.lcdui.Displayable;import javax.microedition.lcdui.Form;import javax.microedition.media.Manager;import javax.microedition.media.MediaException;import javax.microedition.media.Player;import javax.microedition.media.PlayerListener;import javax.microedition.midlet.MIDlet;import javax.microedition.midlet.MIDletStateChangeException;public class Mixing2 extends MIDlet implements CommandListener{private Command play1 = new Command("Play one", Command.OK, 0);private Command play2 = new Command("Play two", Command.OK, 1);private Command play3 = new Command("Play three", Command.OK, 6);private Command stop1 = new Command("Stop one", Command.CANCEL, 2);private Command stop2 = new Command("stop two", Command.CANCEL, 3);private Command stop3 = new Command("stop three", Command.CANCEL, 7);private Command playMix = new Command("play mix", Command.OK, 4);private Command stopRecord = new Command("stop record", Command.OK, 5);private Player player1;private Player player2;private Player player3;private Player player4;private String[] urls = {"/128kbps/intwap-5.wav","/128kbps/intwap-6.wav","/128kbps/intwap-7.wav"};private Form form = new Form("Test mixing");private byte[][] data = new byte[3][];private int[][] times = new int[3][];private long startTime = 0;private long size;private int idx1 = 0;private int idx2 = 0;private int idx3 = 0;private static final int FIRST = 1;private static final int SECOND = 2;private static final int THIRD = 3;private boolean start = false;public Mixing2() {}protected void destroyApp(boolean arg0) throws MIDletStateChangeException {}protected void pauseApp() {}protected void startApp() throws MIDletStateChangeException {form.addCommand(play1);form.addCommand(stop1);form.addCommand(play2);form.addCommand(stop2);form.addCommand(play3);form.addCommand(stop3);form.addCommand(playMix);form.addCommand(stopRecord);form.setCommandListener(this);Display.getDisplay(this).setCurrent(form);}public void commandAction(Command arg0, Displayable arg1) {if (arg0 == play1) {form.append("play one");if(startTime == 0) startTime = System.currentTimeMillis();new Thread(){public void run() {try {stopPlayer1();(player1 = initPlayer(FIRST)).start();} catch (MediaException e) {e.printStackTrace();}}}.start();System.out.println("player1.start.time: "+System.currentTimeMillis());}else if (arg0 == stop1) {stopPlayer1();}else if (arg0 == play2) {form.append("play two");if(startTime == 0) startTime = System.currentTimeMillis();new Thread(){public void run() {try {stopPlayer2();(player2 = initPlayer(SECOND)).start();} catch (MediaException e) {e.printStackTrace();}}}.start();}else if (arg0 == stop2) {stopPlayer2();}else if (arg0 == play3) {form.append("play three");if(startTime == 0) startTime = System.currentTimeMillis();new Thread(){public void run() {try {stopPlayer3();(player3 = initPlayer(THIRD)).start();} catch (MediaException e) {e.printStackTrace();}}}.start();}else if (arg0 == stop3) {stopPlayer3();}else if (arg0 == playMix) {new Thread(){public void run() {try {ByteArrayOutputStream bos = new ByteArrayOutputStream();byte[] data = mixing();System.out.println("combine.................data "+data.length);try {bos.write(new WaveHeader(data.length, (short)16, 8000).getHeader());bos.write(data);} catch (IOException e) {e.printStackTrace();}System.out.println("ready....stop....player........ ");stopPlayer4();System.out.println("ready....mix....player........ ");player4 = Manager.createPlayer(new ByteArrayInputStream(bos.toByteArray()), "audio/x-wav");player4.prefetch();player4.realize();player4.start();} catch (IOException e) {e.printStackTrace();} catch (MediaException e) {e.printStackTrace();}System.out.println("playing.........mix.......data ");for(int i=0;i<times.length;i++){times[i] = null;}startTime = 0;idx1 = idx2 = idx3 = 0;};}.start();}else if (arg0 == stopRecord) {stopPlayer1();stopPlayer2();stopPlayer3();System.gc();}}private void saveToDisk(){//FileConnection file = (FileConnection)Connector.open("file://localhost/" + );}private byte[] mixing(){size = (System.currentTimeMillis() - startTime) * 16;long start = System.currentTimeMillis();byte[] mixData = new byte[(int) size];byte[][] mixPices = new byte[times.length][];System.out.println("111111111111: "+size);for(int i=0; i< times.length;i++){if(times[i]==null) continue;mixPices[i] = new byte[(int) size];int length = data[i].length-44;for(int j =0; j<times[i].length;j++){if(times[i][j]==0)break;System.out.println("player"+i+".time: "+times[i][j]);if((j+1)%2==0)System.out.println((times[i][j]-times[i][j-1]));if((j+1)%2==0) {int max = times[i][j]-times[i][j-1];for (int k = 44; k < max; k++){if(k >= length) break;mixPices[i][(int) times[i][j-1]+k-44] = data[i][k];}}}}System.out.println("999999999999: "+(System.currentTimeMillis() - start));double f = 1.0f;int MAX = 127, MIN = -127;double STEPSIZE;for(int m=0;m<mixData.length;m++){mixData[m] = 0;double temp = 0;for(int n =0;n<mixPices.length;n++){if(mixPices[n]==null) continue;temp += mixPices[n][m];}if(temp==0) continue;temp = temp * f;if(temp>MAX){double f0 = 127.0f/temp;f = f0;temp = MAX;}else if(temp < MIN){double f0 = -127.0f/temp;f = f0;temp = (byte) MIN;}if(f<1) {STEPSIZE = ((1.0f-f)/16);f += STEPSIZE;}mixData[m] = (byte) temp;}for(int n =0;n<mixPices.length;n++){mixPices[n] = null;}mixPices = null;System.out.println("mix cost time: "+(System.currentTimeMillis()-start));return mixData;}private Player initPlayer(int p){byte[] temp = null;PlayerListener plistener = null;if( p == FIRST) {if (data[0]==null) {data[0] = getWaveData(urls[0]);}temp = data[0];plistener = p1;}else if(p==SECOND) {if(data[1]==null){data[1] = getWaveData(urls[1]);}temp = data[1];plistener = p2;}else if(p==THIRD) {if(data[2]==null){data[2] = getWaveData(urls[2]);}temp = data[2];plistener = p3;}Player player = null;try {InputStream is = new ByteArrayInputStream(temp);player = Manager.createPlayer(is, "audio/x-wav");player.prefetch();player.realize();player.addPlayerListener(plistener);//player.setLoopCount(-1);} catch (MediaException e) {e.printStackTrace();}catch (IOException e) {e.printStackTrace();}return player;}private void stopPlayer1(){if(player1!=null && player1.getState() != Player.CLOSED){form.append("stop one");try {player1.stop();player1.close();player1 = null;//System.gc();} catch (MediaException e) {e.printStackTrace();}}}private void stopPlayer2(){if(player2!=null && player2.getState() != Player.CLOSED){form.append("stop two");try {player2.stop();player2.close();player2 = null;//System.gc();} catch (MediaException e) {e.printStackTrace();}}}private void stopPlayer3(){if(player3!=null && player3.getState() != Player.CLOSED){form.append("stop three");try {player3.stop();player3.close();player3 = null;//System.gc();} catch (MediaException e) {e.printStackTrace();}}}private void stopPlayer4(){if(player4!=null && player4.getState() != Player.CLOSED){form.append("stop mix");try {player4.stop();player4.close();player4 = null;//System.gc();} catch (MediaException e) {e.printStackTrace();}}}PlayerListener p1 = new PlayerListener(){public void playerUpdate(Player arg0, String arg1, Object arg2) {if(arg1.equals(PlayerListener.END_OF_MEDIA)){System.out.println("end of media");//System.out.println(System.currentTimeMillis());times[0][idx1] = (int) ((System.currentTimeMillis() - startTime) * 16);idx1++;System.out.println("  player1.cost.time: "+arg0.getMediaTime());}else if(arg1.equals(PlayerListener.STOPPED)){System.out.println("stopped");times[0][idx1] = (int) ((System.currentTimeMillis() - startTime) * 16);idx1++;//System.out.println(System.currentTimeMillis());}else if(arg1.equals(PlayerListener.STARTED)){System.out.println("started");if(times[0] == null) times[0] = new int[100];times[0][idx1] = (int) ((System.currentTimeMillis() - startTime) * 16);idx1++;System.out.println(System.currentTimeMillis());}}};PlayerListener p2 = new PlayerListener(){public void playerUpdate(Player arg0, String arg1, Object arg2) {if(arg1.equals(PlayerListener.STARTED)){System.out.println("started");if(times[1] == null) times[1] = new int[100];times[1][idx2] = (int) ((System.currentTimeMillis() - startTime) * 16);idx2++;//System.out.println(System.currentTimeMillis());}else if(arg1.equals(PlayerListener.STOPPED)){System.out.println("stopped");times[1][idx2] = (int) ((System.currentTimeMillis() - startTime) * 16);idx2++;//System.out.println(System.currentTimeMillis());}else if(arg1.equals(PlayerListener.END_OF_MEDIA)){System.out.println(player2.getState());times[1][idx2] = (int) ((System.currentTimeMillis() - startTime) * 16);idx2++;}}};PlayerListener p3 = new PlayerListener(){public void playerUpdate(Player arg0, String arg1, Object arg2) {if(arg1.equals(PlayerListener.STARTED)){System.out.println("started");if(times[2] == null) times[2] = new int[100];times[2][idx3] = (int) ((System.currentTimeMillis() - startTime) * 16);idx3++;//System.out.println(System.currentTimeMillis());}else if(arg1.equals(PlayerListener.STOPPED)){System.out.println("stopped");times[2][idx3] = (int) ((System.currentTimeMillis() - startTime) * 16);idx3++;//System.out.println(System.currentTimeMillis());}else if(arg1.equals(PlayerListener.END_OF_MEDIA)){System.out.println(player3.getState());times[2][idx3] = (int) ((System.currentTimeMillis() - startTime) * 16);idx3++;}}};private byte[] getWaveData(String url){ByteArrayOutputStream bos = new ByteArrayOutputStream();InputStream is = getClass().getResourceAsStream(url);//int m = 0;byte[] d = new byte[2048];while(true){try {int t = is.read(d);//m = is.read();if(t==-1) break;bos.write(d);} catch (IOException e) {e.printStackTrace();}}byte[] data = bos.toByteArray();System.out.println(data.length);try {is.close();bos.close();} catch (IOException e) {e.printStackTrace();}return data;}}