Why doesn't the MediaRecorder function cause ANR error?
I start a service to reord screen using MediaRecorder and MediaProjection function in Android 5.1 , I think the code Method 1 will cause Application Not Responding error because it works in main thread.
I test the code Method 1 to recode screen long time, it doesn't occur "Application Not Responding error", why? Does it mean that the function MediaRecorder and MediaProjection worked in separated thread?
In the code Method 2 , I create a thread to run mRecordHelper.StartRecord(mRecordArg,resultCode,mIntent); but I get the error java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare(), why?
Thanks for your help.
Call Code
MPublicPar.RecordArg mRecordArg =new MPublicPar().new RecordArg(mContext);
Intent intent = new Intent(mContext,bll.RecordService.class);
intent.putExtra("resultCode",resultCode);
intent.putExtra("dataIntent",data);
intent.putExtra("mRecordArg",mRecordArg);
startService(intent);
Method 1
public class RecordService extends Service {
private RecordHelper mRecordHelper;
private Context mContext;
@Override
public void onCreate(){
mContext=this;
mRecordHelper=new RecordHelper(mContext);
}
@Override
public void onDestroy(){
mRecordHelper.StopRecord();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
final int resultCode=intent.getIntExtra("resultCode",0);
final Intent mIntent=(Intent)intent.getParcelableExtra("dataIntent");
final MPublicPar.RecordArg mRecordArg=(MPublicPar.RecordArg)intent.getSerializableExtra("mRecordArg");
mRecordHelper.StartRecord(mRecordArg,resultCode,mIntent);
return super.onStartCommand(intent, flags, startId);
}
}
Method 2
public class RecordService extends Service {
private RecordHelper mRecordHelper;
private Context mContext;
@Override
public void onCreate(){
mContext=this;
mRecordHelper=new RecordHelper(mContext);
}
@Override
public void onDestroy(){
mRecordHelper.StopRecord();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
final int resultCode=intent.getIntExtra("resultCode",0);
final Intent mIntent=(Intent)intent.getParcelableExtra("dataIntent");
final MPublicPar.RecordArg mRecordArg=(MPublicPar.RecordArg)intent.getSerializableExtra("mRecordArg");
new Thread(new Runnable() {
public void run() {
mRecordHelper.StartRecord(mRecordArg,resultCode,mIntent);
}
}).start();
return super.onStartCommand(intent, flags, startId);
}
}
RecordHelper.cs
public class RecordHelper {
private MediaRecorder mMediaRecorder;
private MediaProjection mMediaProjection;
private VirtualDisplay mVirtualDisplay;
private MediaProjectionManager mProjectionManager;
private Context mContext;
private Toast mToastText;
public RecordHelper(Context mContext){
this.mContext=mContext;
mProjectionManager = (MediaProjectionManager) mContext.getSystemService(Context.MEDIA_PROJECTION_SERVICE);
mMediaRecorder = new MediaRecorder();
}
public void StartRecord(RecordArg mRecordArg, int resultCode, Intent data){
initRecorder(mRecordArg);
prepareRecorder();
mMediaProjection = mProjectionManager.getMediaProjection(resultCode, data);
MediaProjectionCallback mMediaProjectionCallback = new MediaProjectionCallback();
mMediaProjection.registerCallback(mMediaProjectionCallback, null);
mVirtualDisplay=createVirtualDisplay(mRecordArg);
DelayStartRecord(mRecordArg);
}
public void StopRecord(){
try {
mMediaRecorder.stop();
mMediaRecorder.reset();
mVirtualDisplay.release();
mMediaRecorder.release();
mMediaProjection.stop();
mMediaProjection = null;
}catch (Exception e){
Utility.LogError("StopRecord Error " + e.getMessage() + " " + e.toString());
}
}
private void DelayStartRecord(RecordArg mRecordArg){
mMediaRecorder.start();
}
private void initRecorder(RecordArg mRecordArg) {
mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
mMediaRecorder.setVideoEncodingBitRate(512 * 1000);
mMediaRecorder.setVideoFrameRate(30);
mMediaRecorder.setVideoSize(mRecordArg.screenWidth, mRecordArg.screenHeight);
mMediaRecorder.setOutputFile(mRecordArg.videoFilename);
}
private void prepareRecorder() {
try {
mMediaRecorder.prepare();
} catch (IllegalStateException e) {
e.printStackTrace();
Utility.LogError(e.getMessage());
} catch (IOException e) {
e.printStackTrace();
Utility.LogError(e.getMessage());
}
}
private VirtualDisplay createVirtualDisplay(RecordArg mRecordArg) {
return mMediaProjection.createVirtualDisplay("ScreenRecord",
mRecordArg.screenWidth, mRecordArg.screenHeight, mRecordArg.mScreenDensity,
DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR,
mMediaRecorder.getSurface(), null /*Callbacks*/, null /*Handler*/);
}
//Called when the MediaProjection session is no longer valid.
private class MediaProjectionCallback extends MediaProjection.Callback {
@Override
public void onStop() {
}
}
}
but I get the error java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare(), why?
i guess you know hence your second question. The fact that if you call mRecordHelper.StartRecord(mRecordArg,resultCode,mIntent); on the Main thread, does not mean all code functions runs on that thread, all it does is it updates the UI informations on the calling Thread-which is the main thread, and the hard work on a background Thread. if you xplicitly call from a different thread you are instructing it to change a UI object from that thread hence you get that exception- picture a class using async task, or SurfaceView , do not get confused sir, you can always go check the source code and see how it works.
This is not a big deal -(i humbly speak)
why? Does it mean that the function MediaRecorder and MediaProjection worked in separated thread?
check the above -i guess yes
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