MediaRecorder registrazione solo in 15 FPS

Question

Sto realizzando un'app per fotocamera e ho un problema, non riesco a impostare la frequenza fotogrammi del video, il mio codice assomiglia a questo Sto impostando il frame rate su 30, ma lo ignora e registra in 15, so che su alcuni dispositivi non sta impostando la frequenza fotogrammi effettiva ma il frame rate suggerito, e il telefono decide in base all'illuminazione, ma ho registrato all'esterno in luce e stava ancora registrando in un bassi fps, probabilmente sto facendo qualcosa di sbagliato record fotocamera app

MediaRecorder recorder; 
Camera camera; 
SurfaceView preview; 
SurfaceHolder holder; 
boolean isRecording = false; 
String TAG = "Evolution Camera"; 
int frameRate = 30; 


public static final int MEDIA_TYPE_IMAGE = 1; 
public static final int MEDIA_TYPE_VIDEO = 2; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
      WindowManager.LayoutParams.FLAG_FULLSCREEN); 
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE); 
    setContentView(R.layout.camera_view); 

    preview = (SurfaceView) findViewById(R.id.camera_preview); 


// Add a listener to the Capture button 
    ImageButton captureButton = (ImageButton) findViewById(R.id.btn_capture); 
    captureButton.setOnClickListener(
     new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       record(); 
      } 
     } 
    ); 
} 
private boolean prepareVideoRecorder(){ 

    camera = getCameraInstance(); 

    recorder = new MediaRecorder(); 

    // Step 1: Unlock and set camera to MediaRecorder 
    camera.unlock(); 
    recorder.setCamera(camera); 

    // Step 2: Set sources 
    recorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER); 
    recorder.setVideoSource(MediaRecorder.VideoSource.CAMERA); 

    // Step 3: Set a CamcorderProfile (requires API Level 8 or higher) 
    recorder.setProfile(CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH)); 

    recorder.setVideoFrameRate(frameRate); 

    // Step 4: Set output file 
    recorder.setOutputFile(getOutputMediaFile(MEDIA_TYPE_VIDEO).toString()); 



    // Step 5: Set the preview output 
    recorder.setPreviewDisplay(preview .getHolder().getSurface()); 



    // Step 6: Prepare configured MediaRecorder 
    try { 
     recorder.prepare(); 
    } catch (IllegalStateException e) { 
     Log.d(TAG, "IllegalStateException preparing MediaRecorder: " + e.getMessage()); 
     releaseMediaRecorder(); 
     return false; 
    } catch (IOException e) { 
     Log.d(TAG, "IOException preparing MediaRecorder: " + e.getMessage()); 
     releaseMediaRecorder(); 
     return false; 
    } 
    return true; 
} 

void record() 
{ 

    if (isRecording) { 
     // stop recording and release camera 
     recorder.stop(); // stop the recording 
     releaseMediaRecorder(); // release the MediaRecorder object 
     camera.lock();   // take camera access back from MediaRecorder 

     // inform the user that recording has stopped 
     //setCaptureButtonText("Capture"); 
     isRecording = false; 
    } else { 
     // initialize video camera 
     if (prepareVideoRecorder()) { 
      // Camera is available and unlocked, MediaRecorder is prepared, 
      // now you can start recording 
      recorder.start(); 
      setParameters(); 

      // inform the user that recording has started 
      //setCaptureButtonText("Stop"); 
      isRecording = true; 
     } else { 
      // prepare didn't work, release the camera 
      releaseMediaRecorder(); 
      // inform user 
     } 
    } 
} 

void setParameters() 
{ 
// set Camera parameters 
    Camera.Parameters params = camera.getParameters(); 

    if (params.getMaxNumMeteringAreas() > 0){ // check that metering areas are supported 
     List<Camera.Area> meteringAreas = new ArrayList<Camera.Area>(); 

     Rect areaRect1 = new Rect(-100, -100, 100, 100); // specify an area in center of image 
     meteringAreas.add(new Camera.Area(areaRect1, 600)); // set weight to 60% 
     Rect areaRect2 = new Rect(800, -1000, 1000, -800); // specify an area in upper right of image 
     meteringAreas.add(new Camera.Area(areaRect2, 400)); // set weight to 40% 
     params.setMeteringAreas(meteringAreas); 

    } 
    params.setFocusMode(Camera.Parameters.FOCUS_MODE_INFINITY); 

    camera.setParameters(params); 
} 

    @Override 
    protected void onPause() { 
     super.onPause(); 
     if (isRecording) { 
      recorder.stop(); // stop the recording 
      releaseMediaRecorder(); // release the MediaRecorder object 
      camera.lock(); 
      isRecording = false; 
     } 
     else { 

      releaseMediaRecorder(); 
     } 
     releaseCamera();  
    } 

    private void releaseMediaRecorder(){ 
     if (recorder != null) { 
      recorder.reset(); // clear recorder configuration 
      recorder.release(); // release the recorder object 
      recorder = null; 
      camera.lock();   // lock camera for later use 
     } 
    } 

    private void releaseCamera(){ 
     if (camera != null){ 
      camera.release();  // release the camera for other applications 
      camera = null; 
     } 
    } 




/** Create a file Uri for saving an image or video */ 
private static Uri getOutputMediaFileUri(int type){ 
     return Uri.fromFile(getOutputMediaFile(type)); 
} 

/** Create a File for saving an image or video */ 
private static File getOutputMediaFile(int type){ 
    // To be safe, you should check that the SDCard is mounted 
    // using Environment.getExternalStorageState() before doing this. 

    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
       Environment.DIRECTORY_DCIM), "Evolution"); 
    // This location works best if you want the created images to be shared 
    // between applications and persist after your app has been uninstalled. 

    // Create the storage directory if it does not exist 
    if (! mediaStorageDir.exists()){ 
     if (! mediaStorageDir.mkdirs()){ 
      Log.d("MyCameraApp", "failed to create directory"); 
      return null; 
     } 
    } 

    // Create a media file name 
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()); 
    File mediaFile; 
    if (type == MEDIA_TYPE_IMAGE){ 
     mediaFile = new File(mediaStorageDir.getPath() + File.separator + 
     "IMG_"+ timeStamp + ".jpg"); 

    } else if(type == MEDIA_TYPE_VIDEO) { 
     mediaFile = new File(mediaStorageDir.getPath() + File.separator + 
     "VID_"+ timeStamp + ".mp4"); 
     Log.d("MyCameraApp", "File created "+ mediaStorageDir.getPath().toString()); 
    } else { 
     return null; 
    } 


    return mediaFile; 
} 

public static Camera getCameraInstance(){ 
    Camera c = null; 
    try { 
     c = Camera.open(); // attempt to get a Camera instance 
    } 
    catch (Exception e){ 
     // Camera is not available (in use or does not exist) 
    } 
    return c; // returns null if camera is unavailable 
} 

@Override 
public void onPreviewFrame(byte[] data, Camera camera) { 
    // TODO Auto-generated method stub 

} 
@Override 
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { 
    // TODO Auto-generated method stub 

} 
@Override 
public void surfaceCreated(SurfaceHolder holder) { 
    // TODO Auto-generated method stub 

} 
@Override 
public void surfaceDestroyed(SurfaceHolder holder) { 
    // TODO Auto-generated method stub 
    if (isRecording) { 
     recorder.stop(); 
     isRecording = false; 
    } 
    recorder.release(); 

} 

Il predefinite a 24 fps nelle stesse condizioni

Answer 1

ho risolto con questo

Camera.Parameters params = camera.getParameters(); 
    params.setPreviewFpsRange(24000, 30000); 
camera.setParameters(params); 

Ora sto ricevendo 22-23 fps (credo che sia perché è notte)

Answer 2

Dipende del parametro AutoExposure. Per lavorare con rate telaio fisso in tutte le condizioni di illuminazione (da 14 API, Android 4.0):

Camera.Parameters p = camera.getParameters(); 
p.setPreviewFpsRange(30000, 30000); // 30 fps 
if (p.isAutoExposureLockSupported()) 
    p.setAutoExposureLock(true); 
camera.setParameters(p);