Android AudioTrack播放mp3文件

package com.mediatek.factorymode;

import java.io.File;

import com.itsoft.bfp.R;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioTrack;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class TrumpetActivity extends Activity implements OnClickListener {

private String TAG = "TrumpetActivity";
private String assertFolderName = "Android";
private String assertMusicName = "rich.mp3";
@SuppressLint("SdCardPath")
private String targetFolderPath = Environment.getExternalStorageDirectory()
.getPath() + File.separator + assertFolderName;
private String decodeFilePath = Environment.getExternalStorageDirectory()
.getPath()
+ File.separator
+ assertFolderName
+ File.separator
+ assertMusicName;

private Thread mThread;
private boolean mThreadFlag;
private short[] audioBuffer;
private AudioTrack mAudioTrack;

private int samplerate;
private int mAudioMinBufSize;
private int initRet;
private NativeMP3Decoder mMP3Decoder;

private Button PlayMusic, PauseMusic;
private Button leftSoundChannel, lightSoundChannel;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.trumpet_layout);

FileHelper.copyFolderFromAssets(TrumpetActivity.this, assertFolderName,targetFolderPath);

PlayMusic = (Button) findViewById(R.id.playMusic);
PauseMusic = (Button) findViewById(R.id.PauseMusic);
leftSoundChannel = (Button) findViewById(R.id.leftsoundchannel);
lightSoundChannel = (Button) findViewById(R.id.rightsoundchannel);

PlayMusic.setOnClickListener(this);
PauseMusic.setOnClickListener(this);
leftSoundChannel.setOnClickListener(this);
lightSoundChannel.setOnClickListener(this);

mMP3Decoder = new NativeMP3Decoder();

initRet = mMP3Decoder.initAudioPlayer(decodeFilePath, 0);
//对于边下载边解密边解码.思路为先边下载,边解密,下载了3秒后开始解码

if (initRet == -1) {
Log.i(TAG, "Couldn't open file '" + decodeFilePath + "'");
} else {
Log.i(TAG, "Couldn't open file else'" + decodeFilePath + "'");
mThreadFlag = true;
initAudioPlayer();
audioBuffer = new short[1024 * 20];

mThread = new Thread(new Runnable() {

@Override
public void run() {
while (mThreadFlag) {

if (mAudioTrack != null) {
if (mAudioTrack.getPlayState() != AudioTrack.PLAYSTATE_PAUSED) {
if (mAudioTrack != null) {
if (mAudioTrack.getPlayState() != AudioTrack.PLAYSTATE_STOPPED) {
mMP3Decoder.getAudioBuf(audioBuffer,
//此处可以判断返回值是否为0选择跳出循环.另外还可以用条件可以等几次.是不是网络太卡了.没有数据
mAudioTrack.write(audioBuffer, 0,
mAudioMinBufSize);
}
}
} else {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}

}
});

mThread.start();
try {
Thread.sleep(50);
} catch (InterruptedException e) {
e.printStackTrace();
}
mAudioTrack.play();
}
}

public void setChannel(boolean left, boolean right) {
if (null != mAudioTrack) {
mAudioTrack.setStereoVolume(left ? 1 : 0, right ? 1 : 0);
mAudioTrack.play();
}
}

@SuppressWarnings("deprecation")
private void initAudioPlayer() {
samplerate = mMP3Decoder.getAudioSamplerate();
System.out.println("samplerate = " + samplerate);
Log.d("bfp", "samplerate:" + samplerate);
samplerate = samplerate / 2;

mAudioMinBufSize = AudioTrack.getMinBufferSize(samplerate,
AudioFormat.CHANNEL_CONFIGURATION_STEREO,
AudioFormat.ENCODING_PCM_16BIT);

mAudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,

samplerate, AudioFormat.CHANNEL_CONFIGURATION_STEREO,
AudioFormat.ENCODING_PCM_16BIT, mAudioMinBufSize,
AudioTrack.MODE_STREAM);

}

@Override
protected void onDestroy() {
mThreadFlag = false;
try {
Thread.sleep(200);
} catch (InterruptedException e) {
e.printStackTrace();
}

if (mAudioTrack != null) {
if (mAudioTrack.getPlayState() == AudioTrack.PLAYSTATE_PLAYING) {
mAudioTrack.stop();
mAudioTrack.release();
}
}

mAudioTrack = null;
audioBuffer = null;
mMP3Decoder.closeAduioFile();
super.onDestroy();

}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.playMusic:

if (initRet == -1) {
Toast.makeText(getApplicationContext(),
"Couldn't open file '" + decodeFilePath + "'",
Toast.LENGTH_SHORT).show();
} else {
if (mAudioTrack.getPlayState() == AudioTrack.PLAYSTATE_STOPPED) {
mAudioTrack.play();
} else if (mAudioTrack.getPlayState() == AudioTrack.PLAYSTATE_PAUSED) {
mAudioTrack.play();

} else {
Toast.makeText(getApplicationContext(),
"Already in play", Toast.LENGTH_SHORT).show();
}
}

break;
case R.id.PauseMusic:
if (initRet == -1) {
Log.i("conowen", "Couldn't open file '" + decodeFilePath + "'");
Toast.makeText(getApplicationContext(),
"Couldn't open file '" + decodeFilePath + "'",
Toast.LENGTH_SHORT).show();
} else {
if (mAudioTrack.getPlayState() == AudioTrack.PLAYSTATE_PLAYING) {
mAudioTrack.pause();
} else {
Toast.makeText(getApplicationContext(), "Already stop",
Toast.LENGTH_SHORT).show();
}

}
break;
case R.id.leftsoundchannel:
setChannel(true, false);
break;
case R.id.rightsoundchannel:
setChannel(false, true);
break;

default:
break;
}
}
}