android - trasera - no puedo cambiar la camara frontal

cambiar la cámara frontal/delantera sobre la marcha

Question

Si uso solo CAMERA_FACING_BACK o CAMERA_FACING_FRONT todo funciona bien.

Tengo problemas con el cambio de CAMERA_FACING_BACK a CAMERA_FACING_FRONT .

Mi fragmento de código:

public class PhotoCameraActivity extends Activity implements OnClickListener {
private SurfaceView cameraView;
private Button turnButton;
private Camera camera = null;
private Callback listener;
private static int camId = Camera.CameraInfo.CAMERA_FACING_BACK;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.photo_camera_main);
    prepareActivity();
}

private void prepareActivity() {
    cameraView = (SurfaceView) findViewById(R.id.photo_camera_surface_view);

    turnButton = (ImageButton) findViewById(R.id.turn_button);
    turnButton.setOnClickListener(this);
}

@Override
public void onClick(View v) {
    if (v.equals(turnButton)) {
        if (Camera.getNumberOfCameras() > 1 && camId < Camera.getNumberOfCameras() - 1) {
            startCamera(camId + 1);
        } else {
            startCamera(Camera.CameraInfo.CAMERA_FACING_BACK);
        }
    } 
}

@Override
protected void onResume() {
    startCamera(camId);
    super.onResume();
}

@Override
protected void onPause() {
    stopCamera();
    super.onPause();
}

private void startCamera(int cameraId) {
    if (camera != null) {
        stopCamera();
    }       
    holder = cameraView.getHolder();
    listener = new Callback() {

        @Override
        public void surfaceDestroyed(SurfaceHolder holder) {
        }

        @Override
        public void surfaceCreated(SurfaceHolder holder) {
            try {
                camera.setPreviewDisplay(holder);
                camera.startPreview();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void surfaceChanged(SurfaceHolder holder, int format, int           width, int height) {}
    };
    holder.addCallback(listener);


    camId = cameraId;
    camera = Camera.open(cameraId);
    Camera.Parameters params = camera.getParameters();
    if (cameraId == Camera.CameraInfo.CAMERA_FACING_BACK) {
        params.setPreviewSize(1280, 800);
    } else {
        params.setPreviewSize(640, 480);
    }
    camera.setParameters(params);

}

private void stopCamera(){
    System.out.println("stopCamera method");
    if (camera != null){
        camera.stopPreview();
        camera.setPreviewCallback(null);
        camera.release();
        camera = null;
        holder.removeCallback(listener);
        holder = null;
    }
}

}

Answer 1

En onCreate () de mi actividad agrego lo siguiente onClick listener a un botón superpuesto en mi Vista previa SurfaceView (hay numerosos ejemplos en la web para la vista previa):

ImageButton useOtherCamera = (ImageButton) findViewById(R.id.useOtherCamera);
//if phone has only one camera, hide "switch camera" button
if(Camera.getNumberOfCameras() == 1){
    useOtherCamera.setVisibility(View.INVISIBLE);
}
else {
    useOtherCamera.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
    if (inPreview) {
        camera.stopPreview();
    }
    //NB: if you don''t release the current camera before switching, you app will crash
    camera.release();

    //swap the id of the camera to be used
    if(currentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK){
        currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
    }
    else {
        currentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
    }
    camera = Camera.open(currentCameraId);
    //Code snippet for this method from somewhere on android developers, i forget where
    setCameraDisplayOrientation(CameraActivity.this, currentCameraId, camera);
    try {
        //this step is critical or preview on new camera will no know where to render to
        camera.setPreviewDisplay(previewHolder);
    } catch (IOException e) {
        e.printStackTrace();
    }
    camera.startPreview();
}

En mi dispositivo de prueba, la cámara trasera tiene una ID de 0 y la delantera tiene una ID de 1. Sugiero usar las variables estáticas de Camera.CameraInfo para los valores de identificación de su cámara en lugar de los valores codificados. Estoy seguro de que solo causará problemas en otros dispositivos.

Answer 2

Quité y volví a agregar SurfaceView en mi diseño y así funcionó.

public void switchCamera(int cameraType)
{
    if(context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FRONT))
    {
        if(Camera.getNumberOfCameras() > cameraType)
        {
            // Set selected camera
            this.cameraType = cameraType;
        }
        else
        {
            // Set default camera (Rear)
            this.cameraType = Camera.CameraInfo.CAMERA_FACING_BACK;
        }

        if(mCamera != null)
        {
            // Destroy previuos Holder
            surfaceDestroyed(holder);
            holder.removeCallback(this);

            // Remove and re-Add SurfaceView
            ViewGroup rootLayout = (ViewGroup) surface.getParent();
            rootLayout.removeView(surface);
            surface = new SurfaceView(context);
            holder = surface.getHolder();
            holder.addCallback(this);
            rootLayout.addView(surface, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
        }
    }
}

Answer 3

Reinicio la actividad con cameraId = 2 y esto está funcionando.

Answer 4

Tengo que eliminar la vista previa de la superficie antes de agregar una nueva:

if (mPreview != null) {
        mPreview.surfaceDestroyed(mPreview.getHolder());
        mPreview.getHolder().removeCallback(mPreview);
        mPreview.destroyDrawingCache();
        FrameLayout preview = (FrameLayout) view.findViewById(R.id.camera_frame);
        preview.removeView(mPreview);
        mPreview.mCamera = null;
        mPreview = null;

    }

//then add your preview

Answer 5

Usa este código:

if (mCamera != null) {
      mCamera.stopPreview();                  
      mCamera.release();
      mCamera = null;
}

//swap the id of the camera to be used
if (currentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK)
  currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
else 
  currentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;         

try {                
       mCamera = Camera.open(currentCameraId);   

       mCamera.setDisplayOrientation(90);

       mCamera.setPreviewDisplay(surfaceHolder);               

       mCamera.startPreview();

     } 
catch (Exception e) { e.printStackTrace(); }