我试图将麦克风处获得的音频样本传递给扬声器
这是我正在使用的代码，使用suggestions I obtained here
public class MainActivity extends Activity {
AudioManager am = null;
AudioRecord record =null;
AudioTrack track =null;
final int SAMPLE_FREQUENCY = 44100;
final int SIZE_OF_RECORD_ARRAY = 1024; // 1024 ORIGINAL
final int WAV_SAMPLE_MULTIPLICATION_FACTOR = 1;
int i= 0;
boolean isPlaying = true;
class MyThread extends Thread{
private boolean passThroughMode = true;
/*
@Override
public void run(){
recordAndPlay(passThroughMode);
}
*/
MyThread(){
super();
}
MyThread(boolean newPTV){
this.passThroughMode = newPTV;
}
@Override
public void run(){
short[] lin = new short[SIZE_OF_RECORD_ARRAY];
int num = 0;
// am = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
// am.setMode(AudioManager.MODE_IN_COMMUNICATION);
record.startRecording();
track.play();
// while (passThroughMode) {
while (!isInterrupted()) {
num = record.read(lin, 0, SIZE_OF_RECORD_ARRAY);
for(i=0;i<lin.length;i++)
lin[i] *= WAV_SAMPLE_MULTIPLICATION_FACTOR;
track.write(lin, 0, num);
}
}
/*
public void stopThread(){
passThroughMode = false;
}
*/
}
MyThread newThread;
private void init() {
int min = AudioRecord.getMinBufferSize(SAMPLE_FREQUENCY, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
record = new AudioRecord(MediaRecorder.AudioSource.VOICE_COMMUNICATION, SAMPLE_FREQUENCY, AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT, min);
int maxJitter = AudioTrack.getMinBufferSize(SAMPLE_FREQUENCY, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT);
track = new AudioTrack(AudioManager.MODE_IN_COMMUNICATION, SAMPLE_FREQUENCY, AudioFormat.CHANNEL_OUT_MONO,
AudioFormat.ENCODING_PCM_16BIT, maxJitter, AudioTrack.MODE_STREAM);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setVolumeControlStream(AudioManager.MODE_IN_COMMUNICATION);
init();
newThread = new MyThread(true);
newThread.start();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
/*
private void recordAndPlay(boolean pTM) {
short[] lin = new short[SIZE_OF_RECORD_ARRAY];
int num = 0;
am = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
am.setMode(AudioManager.MODE_IN_COMMUNICATION);
record.startRecording();
track.play();
while (pTM) {
num = record.read(lin, 0, SIZE_OF_RECORD_ARRAY);
for(i=0;i<lin.length;i++)
lin[i] *= WAV_SAMPLE_MULTIPLICATION_FACTOR;
track.write(lin, 0, num);
}
}
*/
public void passStop(View view){
Button playBtn = (Button) findViewById(R.id.playBtn);
// /*
if(!isPlaying){
record.startRecording();
track.play();
isPlaying = true;
playBtn.setText("Pause");
}
else{
record.stop();
track.pause();
isPlaying=false;
playBtn.setText("Pass through");
}
// */
}
/*
@SuppressWarnings("deprecation")
@Override
public void onDestroy(){
newThread.stop();
}
*/
@Override
protected void onDestroy() {
super.onDestroy();
// android.os.Process.killProcess(android.os.Process.myPid());
// killProcess(android.os.Process.myPid());
// newThread.stopThread();
newThread.interrupt();
}
}
在第一次运行期间，程序运行正常，麦克风的声音传递到扬声器，当我按下返回按钮时线程似乎停止，因此当应用程序退出时，传递停止。但是，如果我再次运行应用程序，则不会发生通过。是
newThread = new MyThread(true);
newThread.start();
每次执行应用程序时都会启动一个新线程（也就是调用onCreate（）），还是出于某种原因记得旧线程的状态？如何完全重置此应用程序，以便每次执行一个全新的应用程序时都会启动？
---编辑---
没有中断的替代版本：
public class MainActivity extends Activity {
AudioManager am = null;
AudioRecord record =null;
AudioTrack track =null;
final int SAMPLE_FREQUENCY = 44100;
final int SIZE_OF_RECORD_ARRAY = 1024; // 1024 ORIGINAL
final int WAV_SAMPLE_MULTIPLICATION_FACTOR = 1;
int i= 0;
boolean isPlaying = true;
class MyThread extends Thread{
private volatile boolean passThroughMode = true;
/*
@Override
public void run(){
recordAndPlay(passThroughMode);
}
// */
// /*
MyThread(){
super();
}
MyThread(boolean newPTV){
this.passThroughMode = newPTV;
}
// */
// /*
@Override
public void run(){
short[] lin = new short[SIZE_OF_RECORD_ARRAY];
int num = 0;
// am = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
// am.setMode(AudioManager.MODE_IN_COMMUNICATION);
record.startRecording();
track.play();
while (passThroughMode) {
// while (!isInterrupted()) {
num = record.read(lin, 0, SIZE_OF_RECORD_ARRAY);
for(i=0;i<lin.length;i++)
lin[i] *= WAV_SAMPLE_MULTIPLICATION_FACTOR;
track.write(lin, 0, num);
}
record.stop();
track.stop();
record.release();
track.release();
}
// */
// /*
public void stopThread(){
passThroughMode = false;
}
// */
}
MyThread newThread;
private void init() {
int min = AudioRecord.getMinBufferSize(SAMPLE_FREQUENCY, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);
record = new AudioRecord(MediaRecorder.AudioSource.VOICE_COMMUNICATION, SAMPLE_FREQUENCY, AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT, min);
int maxJitter = AudioTrack.getMinBufferSize(SAMPLE_FREQUENCY, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT);
track = new AudioTrack(AudioManager.MODE_IN_COMMUNICATION, SAMPLE_FREQUENCY, AudioFormat.CHANNEL_OUT_MONO,
AudioFormat.ENCODING_PCM_16BIT, maxJitter, AudioTrack.MODE_STREAM);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setVolumeControlStream(AudioManager.MODE_IN_COMMUNICATION);
init();
Log.d("MYLOG", "onCreate() called");
//Toast.makeText(getApplicationContext(), "HERE", Toast.LENGTH_SHORT).show();
// newThread = new MyThread(true); // -> Moved this to onResume();
// newThread = new MyThread();
// newThread.start(); // -> Moved this to onResume()
// newThread.run();
}
@Override
protected void onResume(){
super.onResume();
// newThread.stopThread();
Log.d("MYLOG", "onResume() called");
newThread = new MyThread(true);
newThread.start();
}
@Override
protected void onPause(){
super.onPause();
Log.d("MYLOG", "onPause() called");
newThread.stopThread();
// android.os.Process.killProcess(android.os.Process.myPid());
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
/*
private void recordAndPlay(boolean pTM) {
short[] lin = new short[SIZE_OF_RECORD_ARRAY];
int num = 0;
am = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
am.setMode(AudioManager.MODE_IN_COMMUNICATION);
record.startRecording();
track.play();
while (pTM) {
num = record.read(lin, 0, SIZE_OF_RECORD_ARRAY);
for(i=0;i<lin.length;i++)
lin[i] *= WAV_SAMPLE_MULTIPLICATION_FACTOR;
track.write(lin, 0, num);
}
}
// */
public void passStop(View view){
Button playBtn = (Button) findViewById(R.id.playBtn);
// /*
if(!isPlaying){
record.startRecording();
track.play();
isPlaying = true;
playBtn.setText("Pause");
}
else{
record.stop();
track.pause();
isPlaying=false;
playBtn.setText("Pass through");
}
// */
}
/*
@SuppressWarnings("deprecation")
@Override
public void onDestroy(){
// newThread.stop();
newThread.stopThread();
}
// */
// /*
@Override
protected void onDestroy() {
super.onDestroy();
newThread.stopThread();
// android.os.Process.killProcess(android.os.Process.myPid());
// killProcess(android.os.Process.myPid());
// newThread.interrupt();
Log.d("MYLOG", "onDestroy() called");
}
// */
}
---编辑2 ---
08-20 20:57:58.266: D/MYLOG(21936): onResume() called
08-20 20:57:58.266: W/dalvikvm(21936): threadid=11: thread exiting with uncaught exception (group=0x416f5700)
08-20 20:57:58.266: E/AndroidRuntime(21936): FATAL EXCEPTION: Thread-897
08-20 20:57:58.266: E/AndroidRuntime(21936): java.lang.IllegalStateException: startRecording() called on an uninitialized AudioRecord.
08-20 20:57:58.266: E/AndroidRuntime(21936): at android.media.AudioRecord.startRecording(AudioRecord.java:517)
08-20 20:57:58.266: E/AndroidRuntime(21936): at com.example.mypassthrough.MainActivity$MyThread.run(MainActivity.java:54)
08-20 20:57:58.286: D/MYLOG(21936): onPause() called
08-20 20:57:58.366: D/MYLOG(21936): onDestroy() called
答案 0 :(得分：1)
不，Thread个实例中没有Activity个对象的状态持久性。 然而，您错误地认为每次运行应用时都会获得新的活动。活动将持续到Android OS决定删除它们为止。只有这样，一旦您再次进入应用程序，就会创建一个新实例 - 否则，您将获得与以前相同的活动，并且在这种情况下不再调用onCreate() 。
换句话说，您应该使用onResume()和onPause()代替init / deinit。有关详细信息，请查看lifecycle page。
编辑：另一个问题是您正在使用interrupt()来控制线程的流量。这并不总是一个好主意，因为interrupt()有several side effects and may not even set the interrupt status to true depending on what's going with the thread。您应该使用“shouldStop”字段，因为那时语义是由您设置的。
请注意，此“shouldStop”字段应为字段，将其作为参数传递将无效。你应该在MyThread中找到类似的东西：
@Override
public void run(){
short[] lin = new short[SIZE_OF_RECORD_ARRAY];
int num = 0;
record.startRecording();
track.play();
while (passThroughMode) {
num = record.read(lin, 0, SIZE_OF_RECORD_ARRAY);
for(i=0;i<lin.length;i++)
lin[i] *= WAV_SAMPLE_MULTIPLICATION_FACTOR;
track.write(lin, 0, num);
}
}
和onPause()：
@Override
protected void onPause() {
super.onPause();
newThread.stopThread();
}
如果线程仍未停止，则调用将阻止它，这对于I / O操作来说是典型的。
编辑2：另一个问题是，当玩家线程为stop()和release()时你没有AudioTrack和AudioRecord关闭（在while循环之后）。 使用与I / O相关的东西时的经验法则是它经常附加到“本机”资源，这需要明确的“手动”释放（有时候是分配）。在这些情况下，您应该始终检查类API。
编辑3： ... MyThread实例以及所有其他资源应在onResume()中初始化完全 ，包括在onCreate()上创建新鲜的实例，不。
答案 1 :(得分：0)
您的线程是一个内部类，它具有并使用对外部类MainActivity的引用。这样，即使新线程对象本身不从先前实例继承任何内容，线程的第二个实例也可能与第一个实例的运行方式不同。正如@TheTerribleSwiftTomato所说，你的活动可能会持续存在。