Android Camera 预览角度和拍照保存图片角度相关

--基于Android R(11)

关于Camera

Camera Framework 的架构

Android Camera Framework 是一个分层架构，由以下组件组成：

• HAL（硬件抽象层）: HAL 抽象底层相机硬件,提供与不同设备相机进行交互的标准接口.
• CameraService : CameraService 是框架的核心,管理相机设备并为应用程序提供访问 HAL 的接口.
• Camera 应用程序 : Camera 应用程序是面向用户的界面,允许用户控制相机设置、预览取景器并拍摄照片或视频.

以 Android 原生 Camera2 应用程序为例,PhotoModule 和 VideoModule 展示了如何使用 Camera Framework 构建高级相机应用程序.

PhotoModule 负责管理照片拍摄.

VideoModule 负责管理视频录制.

Android 最新Camera框架
Camera 架构
AndroidO Camera(API 2)openCamera 流程

关于Camera预览

Camera的图像数据来源于摄像头硬件的图像传感器,图像传感器被固定到手机上后会有一个默认的方向.

如果默认的图像传感器为横向,而所用设备拍照是竖向的,比如手机,但得到的图片数据依然会是横向的,因为这个数据取决于图像传感器的方向.

由于Camera默认是横向的,竖向拍照时得到的照片和预览的照片会有所不同.

Camera1 API 上可以利用setDisplayOrientation(int rotateDegree)设置预览角度调节预览图片.

setDisplayOrientation只是改变了预览的角度,而拍摄生成图片的角度还是和默认图片传感器方向一致.

Camera2 API --通过TextureView.setTransform(matrix) 接口来调整textureView的显示来达到目的,设置预览方向.

./packages/apps/Camera2/src/com/android/camera/one/v2/OneCameraImpl.java:400:                builder.set(CaptureRequest.JPEG_ORIENTATION,
./packages/apps/Camera2/src/com/android/camera/one/v2/SimpleOneCameraFactory.java:199:                rootBuilder.setParam(CaptureRequest.JPEG_ORIENTATION,
./packages/apps/Camera2/src/com/android/camera/one/v2/OneCameraZslImpl.java:824:                builder.set(CaptureRequest.JPEG_ORIENTATION,

public void openCamera(){
      CameraManager manager = (CameraManager) mContext.getSystemService(Context.CAMERA_SERVICE);
        try {
           ......
    //调整预览画面显示方向
        configureTextureViewTransform(mTextureView.getWidth(),mTextureView.getHeight());
            manager.openCamera(cameraId, mStateCallback, null);
           ......
        }
}

private void configureTextureViewTransform(int viewWidth, int viewHeight) {
        if (null == mTextureView) {
            return;
        }
        int rotation = 0 ;/*activity.getWindowManager().getDefaultDisplay().getRotation();*/
        Matrix matrix = new Matrix();
        RectF viewRect = new RectF(0, 0, viewWidth, viewHeight);
        RectF bufferRect = new RectF(0, 0, mPreviewSize.getHeight(), mPreviewSize.getWidth());
        float centerX = viewRect.centerX();
        float centerY = viewRect.centerY();
        if (Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation) {
            bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
            matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
            float scale = Math.max(
                    (float) viewHeight / mPreviewSize.getHeight(),
                    (float) viewWidth / mPreviewSize.getWidth());
            matrix.postScale(scale, scale, centerX, centerY);
            matrix.postRotate(90 * (rotation - 2), centerX, centerY);
        }else if (Surface.ROTATION_180 == rotation) {
            matrix.postRotate(180, centerX, centerY);
        }
        mTextureView.setTransform(matrix);
    }

关于Camera拍照生成图片角度处理

利用Camera拍照时,读取图片数据存储为图片,取到的数据直接来源于图像传感器采集到的图像数据.

所以拍摄生成图片的角度还是和默认图片传感器方向一致.

可以利用代码修改---拍摄生成图片的角度.

Camera2 API -- 通过CaptureRequest.JPEG_ORIENTATION来设置拍照的图像方向

修改生成图片镜像
Android 7.1 RK3288 A40i Camera2 拍照镜像分析

./packages/apps/Camera2/src/com/android/camera/PhotoModule.java

    void saveFinalPhoto(final byte[] jpegData, final ExifInterface exif, CameraProxy camera) {
            if (mNamedImages == null)
                mNamedImages = new NamedImages();
            if (mNamedImages.mQueue.size() == 0)
                mNamedImages.nameNewImage(System.currentTimeMillis());

            int orientation = Exif.getOrientation(exif);

            float zoomValue = 1.0f;
            if (mCameraCapabilities.supports(CameraCapabilities.Feature.ZOOM)) {
                zoomValue = mCameraSettings.getCurrentZoomRatio();
            }
            
            ...
            
                exif.setTag(directionRefTag);
                exif.setTag(directionTag);
            }
            
+           //add text
+           Bitmap bitmap = CameraUtil.makeBitmap(jpegData, exifWidth * exifHeight);//jpeg byte 数组转换为bitmap
+           Matrix matrix = new Matrix();
+           matrix.postScale(-1, 1);//利用matrix 对矩阵进行转换 x轴镜像
+           bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
+           ByteArrayOutputStream baos = new ByteArrayOutputStream();
+           bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);//重新转换为 .jpeg 数据
+           byte [] tm_jpegData = baos.toByteArray();
+           //add text
+
            onMediaSavedListenerAfterBurstCapture mediaSavedListener = new onMediaSavedListenerAfterBurstCapture(
                    (mBurstPictureLength - mIndex));
            getServices().getMediaSaver().addImage(
-                            jpegData, title, date, mLocation, width, height,
+                            tm_jpegData, title, date, mLocation, width, height,
                             orientation, exif, mediaSavedListener);
                }
            // Animate capture with real jpeg data instead of a preview

Android9.0 Camera2 横屏问题修改记录
Android Camera预览角度和拍照保存图片角度学习

修改摄像头旋转方向

可以驱动层,hal层,framework层,app层修改.

--- a/frameworks/base/core/java/android/hardware/Camera.java
+++ b/frameworks/base/core/java/android/hardware/Camera.java
@@ -399,7 +399,7 @@ public class Camera {
      * @see android.app.admin.DevicePolicyManager#getCameraDisabled(android.content.ComponentName)
      */
     public static Camera open(int cameraId) {
-        return new Camera(cameraId);
+        return rotateCamera(i);
     }

     /**
    public static Camera open() {
        int numberOfCameras = getNumberOfCameras();
        CameraInfo cameraInfo = new CameraInfo();   
         for (int i = 0; i < numberOfCameras; i++) {
             getCameraInfo(i, cameraInfo);
             if (cameraInfo.facing == CameraInfo.CAMERA_FACING_BACK) {
-                return new Camera(i);
+                return rotateCamera(i);
             }
         }
         return null;
     }

+    //add text
+    private static Camera rotateCamera(int cameraId) {
+        Camera camera = new Camera(cameraId);
+        Parameters parameters = camera.getParameters();
+        CameraInfo cameraInfo = new CameraInfo();
+        getCameraInfo(cameraId, cameraInfo);
+        if (cameraInfo.facing == CameraInfo.CAMERA_FACING_BACK) {//0 后置
+            camera.setDisplayOrientation(270);
+            parameters.setRotation(270);
+        } else if (cameraInfo.facing == CameraInfo.CAMERA_FACING_FRONT) {// 1 前置
+            camera.setDisplayOrientation(90);
+            parameters.setRotation(90);
+        }
+        camera.setParameters(parameters);
+        return camera;
+    }
+    //add text
+

修改某个apk应用拿到的SENSOR_ORIENTATION方向,影响Camera拍照生成图片角度.

frameworks/base/core/java/android/hardware/camera2/CameraCharacteristics.java

    @PublicKey
    @NonNull
    public static final Key<Integer> SENSOR_ORIENTATION =
            new Key<Integer>("android.sensor.orientation", int.class);

    @Nullable
    public <T> T get(Key<T> key) {
        //add text  
        Log.d("tag",  "Activity name: " + ActivityThread.currentActivityThread().currentActivityName() + " ,key = " + key);
            if(key != null && SENSOR_ORIENTATION.equals(key)){
                if(ActivityThread.currentOpPackageName().contains("com.xxx")){
                    //String cameraId = CameraManager.getCameraId();
                    if(cameraId != null){
                        T value = (T)(Object)90;
                        Log.d("tag",  "value = " + value + " ,ori = " + mProperties.get(key));
                        return value;
                }
            }
        //add text    
        return mProperties.get(key);
    }   

三方Camera App Framework方向控制（API2）

改变摄像头成像方向

camera3_profiles_rk356x.xml,这个配置说明了这个板子所有支持的摄像头配置.

RK 硬件的camera配置文件中找到ov8858摄像头设备，并修改其sensor.orientation value 的值.

hardware/rockchip/camera/etc/camera/camera3_profiles_rk356x.xml
<Profiles cameraId="0" name="ov8858" moduleId="m00">
        <Supported_hardware>
            <hwType value="SUPPORTED_HW_RKISP1"/>
        </Supported_hardware>
        ...
    <!-- Sensor -->
    <sensor.orientation value="270"/><!-- Sensor -->

rk356x OpenCamera流程浅析