Android Camera2預覽在風景中旋轉90度

Question

我跟隨youtube tutorial，試圖學習Camera2 API。當然，我在開發自己的應用程序的同時正在學習這一點。教程和我的應用程序之間的一個不一致之處在於，教程僅在我的應用程序處於橫向模式時纔將相機設置爲縱向模式。

我目前能夠查看相機的預覽，儘管當我的應用處於橫向或橫向時，相機預覽看起來旋轉了90度。它幾乎感覺我可以旋轉TextureView，但看起來不正確，就像我拍照時，它會被錯誤地旋轉。

下面是與圖像尺寸做的代碼（整個代碼很長）

private void setupCamera(int width, int height) { 
    CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE); 
    try { 
     CameraCharacteristics cameraCharacteristics = cameraManager.getCameraCharacteristics(camera_id); 
     StreamConfigurationMap map = cameraCharacteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP); 
     cameraCharacteristics.get(CameraCharacteristics.SENSOR_ORIENTATION); 
     mPreviewSize = getPreferredPreviewSize(map.getOutputSizes(SurfaceTexture.class), width, height); 
     mCameraId = camera_id; 
    } catch (CameraAccessException e) { 
     e.printStackTrace(); 
    } 
} 


//TODO Look for a way to make this horizontal 
private Size getPreferredPreviewSize(Size[] mapSizes, int width, int height) { 
    List<Size> collectorSizes = new ArrayList<>(); 
    for (Size option : mapSizes) { 
     if (width > height) { //If the screen is in landscape 
      Toast.makeText(getApplicationContext(), "Screen is Landscape", Toast.LENGTH_SHORT).show(); 
      if (option.getWidth() > width && option.getHeight() > height) { 
       collectorSizes.add(option); 
      } 
     } else { //if the screen is in portrait 
      Toast.makeText(getApplicationContext(), "Screen is Portrait", Toast.LENGTH_SHORT).show(); 
      if (option.getWidth() > height && option.getHeight() > width) { 
       collectorSizes.add(option); 
      } 
     } 
    } 
    if (collectorSizes.size() > 0) { 
     return Collections.min(collectorSizes, new Comparator<Size>() { 
      @Override 
      public int compare(Size lhs, Size rhs) { 
       return Long.signum(lhs.getWidth() * lhs.getHeight() - rhs.getWidth() + rhs.getHeight()); 
      } 
     }); 
    } 

    return mapSizes[0]; 
} 
private void openCamera() { 
    CameraManager cameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE); 
    try { 
     if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) { 
      return; 
     } 
     cameraManager.openCamera(mCameraId, mCameraDeviceStateCallback, null); 
    } catch (CameraAccessException e){ 
     e.printStackTrace(); 
    } 
} 

private void createCameraPreviewSession() { 
    try { 
     SurfaceTexture surfaceTexture = mTextureView.getSurfaceTexture(); 
     surfaceTexture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight()); 
     Surface previewSurface = new Surface(surfaceTexture); 
     mPreviewCaptureRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW); 
     mPreviewCaptureRequestBuilder.addTarget(previewSurface); 
     mCameraDevice.createCaptureSession(Arrays.asList(previewSurface), 
       new CameraCaptureSession.StateCallback() { 
        @Override 
        public void onConfigured(CameraCaptureSession session) { 
         if(mCameraDevice == null){ 
          return; 
         } 
         try { 
          mPreviewCaptureRequest = mPreviewCaptureRequestBuilder.build(); 
          mCameraCaptureSession = session; 
          mCameraCaptureSession.setRepeatingRequest(mPreviewCaptureRequest, mSessionCaptureCallback, null); 
         } catch (CameraAccessException e){ 
          e.printStackTrace(); 
         } 
        } 

        @Override 
        public void onConfigureFailed(CameraCaptureSession session) { 
         Toast.makeText(getApplicationContext(), "Preview Session Failed", Toast.LENGTH_SHORT).show(); 
        } 
       }, null); 
    } catch (CameraAccessException e){ 
     e.printStackTrace(); 
    } 
} 

我一直在玩的getPreferredPreviewSize方法，但我不明白它，以及我應該。我不確定在使用lhs和rhs的末尾compare。

我是否缺少一些簡單的東西讓它旋轉？

Answer 1

private void transformImage (int width, int height) 
{ 
    if(mPreviewSize == null || mTextureView == null) 
    { 
     return; 
    } 
    Matrix matrix = new Matrix(); 
    int rotation = getWindowManager().getDefaultDisplay().getRotation(); 
    RectF textureRectF = new RectF(0,0,width,height); 
    RectF previewRectF = new RectF(0,0,mPreviewSize.getHeight(),mPreviewSize.getWidth()); 
    float centerX = textureRectF.centerX(); 
    float centery = textureRectF.centerY(); 

    if(rotation == Surface.ROTATION_0 || rotation == Surface.ROTATION_270) 
    {} 
    else if(rotation == Surface.ROTATION_90 || rotation == Surface.ROTATION_270) 
    { 
     previewRectF.offset(centerX - previewRectF.centerX(),centery-previewRectF.centerY()); 
     matrix.setRectToRect(textureRectF,previewRectF,Matrix.ScaleToFit.FILL); 
     float scale = Math.max((float)width/mPreviewSize.getWidth(),(float)height/ mPreviewSize.getHeight()); 

     matrix.postScale(scale,scale,centerX,centery); 
     matrix.postRotate(90*(rotation-2),centerX,centery); 
     mTextureView.setTransform(matrix); 

    }