vendor\mediatek\proprietary\packages\apps 目录下有三份相机源码 分别是

Camera、 Camera1、 Camera2

通过查看 mk 发现通过 ifeq ($(MTK_CAMERA_APP_VERSION), 3) 来控制编译哪一个，

MTK_CAMERA_APP_VERSION 宏定义在 device/mediateksample/xxxxxx/ProjectConfig.mk

整体界面相关

Camera2 中适配了两套 api， 老版本的 Camera 和新版本的 Camera2, 通过 CameraApiHelper 配置

Camera2\common\src\com\mediatek\camera\common\mode\CameraApiHelper.java

public static CameraApi getCameraApiType(@Nullable String modeName) {
        return CameraApi.API2;
}

 public enum CameraApi {
        /** Use the {@link android.hardware.Camera} class. */
        API1,
        /** Use the {@link android.hardware.camera2} package. */
        API2
}

预览布局不延伸到 navigation 中，不显示 statusbar

增加 requestWindowFeature(Window.FEATURE_NO_TITLE)

Camera2\host\src\com\mediatek\camera\QuickActivity.java

@Override
    protected final void onCreate(Bundle bundle) {
        LogHelper.i(TAG, "onCreate()");
        IPerformanceProfile profile = PerformanceTracker.create(TAG, "onCreate").start();
        mStartupOnCreate = true;
        super.onCreate(bundle);

        //cczheng add for don't show statusbar
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        requestWindowFeature(Window.FEATURE_NO_TITLE);

        mMainHandler = new Handler(getMainLooper());
        onPermissionCreateTasks(bundle);
        profile.stop();
    }

注释 setSystemUiVisibility(View.SYSTEM_UI_LAYOUT_FLAGS | View.SYSTEM_UI_FLAG_LAYOUT_STABLE

Camera2\host\src\com\mediatek\camera\CameraActivity.java

@Override
    protected void onCreateTasks(Bundle savedInstanceState) {
        if (!isThirdPartyIntent(this) && !isOpenFront(this)) {
            CameraUtil.launchCamera(this);
        }
        IPerformanceProfile profile = PerformanceTracker.create(TAG, "onCreate").start();
        super.onCreateTasks(savedInstanceState);

        //cczheng annotation for layout forbbiden into navigationbar area
        /*getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_LAYOUT_FLAGS
                | View.SYSTEM_UI_FLAG_LAYOUT_STABLE);*/

        setContentView(R.layout.activity_main);
        mOrientationListener = new OrientationEventListenerImpl(this);
        //create common ui module.
        mCameraAppUI = new CameraAppUI(this);
        profile.mark("CameraAppUI initialized.");
        mCameraAppUI.onCreate();
        profile.mark("CameraAppUI.onCreate done.");
        mIModeListener = new ModeManager();
        mIModeListener.create(this);
        profile.mark("ModeManager.create done.");
        profile.stop();
    }

旋转界面圆形图标 90 度, 闪光灯、HDR、拍照模式等

canvas.rotate(90)

Camera2\common\src\com\mediatek\camera\common\widget\RotateImageView.java

 @Override
    protected void onDraw(Canvas canvas) {
        Drawable drawable = getDrawable();

        if (drawable == null) {
            return;
        }

        Rect bounds = drawable.getBounds();
        int w = bounds.right - bounds.left;
        int h = bounds.bottom - bounds.top;

        ....

         // canvas.rotate(-mCurrentDegree);
        canvas.rotate(90);//cczheng change 90 for rotate all imageView
        canvas.translate(-w / 2, -h / 2);
        if (mDrawableBitmap != null) {
            canvas.drawBitmap(mDrawableBitmap, 0, 0, null);
        } else {
            drawable.draw(canvas);
        }
        canvas.restoreToCount(saveCount);
    }

拍照相关

预览旋转 90

horizontalMirrorData() 和 changePreviewDisplayOrientation() 都是从网上找的简单矩阵算法，验证了还真的能达到效果

镜像的问题底层驱动修改了，app 就不用处理了

预览旋转角度，根据实际情况我注释了 postScale(),这样导致了横屏被拉伸了，人脸变胖了，只需要单纯的 postRotate(90) 即可

Camera2\host\src\com\mediatek\camera\ui\preview\TextureViewController.java

//用于水平翻转镜像
private void horizontalMirrorData(){
        LogHelper.d(TAG, "updatePreviewSize horizontalMirrorData()");
        Matrix matrix = mTextureView.getTransform(new Matrix());
        matrix.setScale(-1, 1);
        int width = mTextureView.getWidth();
        matrix.postTranslate(width, 0);
        mTextureView.setTransform(matrix);
}

//用于旋转预览角度
private void changePreviewDisplayOrientation() {
        int mTextureViewWidth = mTextureView.getWidth();
        int mTextureViewHeight = mTextureView.getHeight();

        int rotation = mApp.getActivity().getWindowManager().getDefaultDisplay().getRotation();
        LogHelper.d(TAG,"rotation="+rotation);
        LogHelper.e(TAG,"mPreviewWidth="+mPreviewWidth+" mPreviewHeight="+mPreviewHeight);
        LogHelper.e(TAG,"textureWidth="+mTextureViewWidth+" textureHeight="+mTextureViewHeight);

        Matrix matrix = new Matrix();
        RectF viewRect = new RectF(0, 0, mTextureViewWidth, mTextureViewHeight);
        RectF bufferRect = new RectF(0, 0, mPreviewHeight, mPreviewWidth);
        float centerX = viewRect.centerX();
        float centerY = viewRect.centerY();
        if (Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation) {
            LogHelper.e(TAG,"Surface.ROTATION_90 ROTATION_270");
            /*bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
            matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
            float scale = Math.max((float) mTextureViewHeight / mPreviewHeight,
                                    (float) mTextureViewWidth / mPreviewWidth);
            LogHelper.d(TAG,"scale="+scale);
            matrix.postScale(scale, scale, centerX, centerY);*/
            matrix.postRotate((90 * (rotation - 2)) % 360, centerX, centerY);
        } else if (Surface.ROTATION_180 == rotation) {
            LogHelper.d(TAG,"Surface.ROTATION_180 =");
            matrix.postRotate(180, centerX, centerY);
        }
        mTextureView.setTransform(matrix);
}

private class SurfaceChangeCallback implements TextureView.SurfaceTextureListener {
        private ISurfaceStatusListener mListener;

        .....

        @Override
        public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
            //cczheng add for mirror preview data
            //horizontalMirrorData();
            changePreviewDisplayOrientation();

            mIsSurfaceCreated = true;
            surface.setDefaultBufferSize(mPreviewWidth, mPreviewHeight);
            if (mListener != null) {
                mListener.surfaceChanged(surface, mPreviewWidth, mPreviewHeight);
            }
            LogHelper.d(TAG, "onSurfaceTextureAvailable surface  = " + surface +
             " width " + width + " height " + height);
        }

        .....
}

人脸框位置相关

因为旋转了屏幕方向，人脸框的坐标位置就不对了，需要调整为正确的

通过分析打印日志发现

CamAp_FaceViewCtrl: [updateFacesViewByFace] new face num = 1, clear hide msg, show view right now

CamAp_FaceViewCtrl: [updateFacesViewByFace] new face num = 1, clear hide msg, send hide msg delay 1500 ms

和人脸框相关的类有以下几个

Camera2\feature\setting\facedetection\src\com\mediatek\camera\feature\setting\facedetection\FaceViewCtrl.java

Camera2\feature\setting\facedetection\src\com\mediatek\camera\feature\setting\facedetection\FaceView.java

Camera2\common\src\com\mediatek\camera\common\utils\CoordinatesTransform.java

FaceViewCtrl 控制显示隐藏， FaceView 绘制人脸框(其实是 ic_face_detection_focusing.9.png 图片)，CoordinatesTransform 转换人脸坐标

看到上面打印的日志，人脸框显示 1.5 s 后会自动隐藏，这应该是 MTK 当时遗留的一个 bug

为了让人脸框一直显示，注释 updateFacesViewByFace() 中的 MSG_FACE_VIEW_HIDE 消息发送

private void updateFacesViewByFace(Face[] faces) {
        if (!mIsEnable) {
            LogHelper.e(TAG, "[updateFacesViewByFace] mIsEnable is false, ignore this time");
            return;
        }
        if (faces != null && faces.length > 0
                && mFaceViewState == FaceViewState.STATE_INIT) {
            // Check if face view has really been shown, if not , not hide view this time.
            // Why to do this check?
            // Maybe higher priority view is shown when face view wants to show, after higher
            // priority view is not shown, maybe face num is not changed too, it's time to hide
            // face view. So face view has no chance to show out.
            if (mHideViewWhenFaceCountNotChange && faces.length == mFaceNum
                    && mFaceView.hasReallyShown()) {
                // if face view is hide now, not send message, only update wait state
                if (mFaceView.getVisibility() != View.VISIBLE) {
                    mMainHandler.removeMessages(MSG_FACE_VIEW_HIDE);
                    mWaitFocusState = WaitFocusState.WAIT_NOTHING;
                } else if (!mMainHandler.hasMessages(MSG_FACE_VIEW_HIDE)) {
                    // if there is not hide msg in queue, send delay message to hide

                    //cczheng annotation don't auto hide faceview 1.5s
                    /*mMainHandler.removeMessages(MSG_FACE_VIEW_HIDE);
                    LogHelper.e(TAG, "[updateFacesViewByFace] new face num = " + faces.length +
                            ", clear hide msg, send hide msg delay "
                            + HIDE_VIEW_TIMEOUT_WAIT_AF_SCAN + " ms");
                    mMainHandler.sendEmptyMessageDelayed(MSG_FACE_VIEW_HIDE,
                            HIDE_VIEW_TIMEOUT_WAIT_AF_SCAN);*/
                }
            } else {
                LogHelper.e(TAG, "[updateFacesViewByFace] new face num = " + faces.length +
                        ", clear hide msg, show view right now");
                mMainHandler.removeMessages(MSG_FACE_VIEW_HIDE);
                mWaitFocusState = WaitFocusState.WAIT_PASSIVE_SCAN;
                showView();
                mFaceView.resetReallyShown();
            }

            mFaceView.setFaces(faces);
            mFaceNum = faces.length;
        }
    }

FaceView 中的 onDraw() 通过遍历人脸集合，绘制人脸框，mFaceIndicator 就是上面说的 .9 图片，来看下坐标的计算方法

@Override
    protected void onDraw(Canvas canvas) {
        LogHelper.i(TAG, "[FaceView onDraw]");
        mReallyShown = true;
        if (mFaces != null && mFaces.length > 0) {
            for (int i = 0; i < mFaces.length; i++) {
                Rect rect = CoordinatesTransform.normalizedPreviewToUi(mFaces[i].rect,
                        mPreviewWidth, mPreviewHeight,
                        mDisplayOrientation, mMirror);
                mFaceIndicator.setBounds(rect.left, rect.top,
                        rect.right, rect.bottom);
                mFaceIndicator.draw(canvas);
            }
        }
        super.onDraw(canvas);
    }

通过传递原始的人脸坐标，和当前实际预览的画布宽高，是否镜像进行计算,

最终通过修改 displayOrientation 为 90，viewWidth 和 viewHeight 由原来的 / 2000f 修改为 /2200f 和 /1500f

当然也可能需要根据你的屏幕实际尺寸调整

public static Rect normalizedPreviewToUi(Rect rect, int w, int h,
                                      int displayOrientation, boolean isMirror) {
        int previewHeight = 0;
        int previewWidth = 0;

        if (displayOrientation == 0 || displayOrientation == 180) {
            previewHeight = h > w ? w : h;//740
            previewWidth = h > w ? h : w;//986
        } else if (displayOrientation == 90 || displayOrientation == 270) {
            previewHeight = h > w ? h : w;//986
            previewWidth = h > w ? w : h;//740
        }
        coordinatesLog(TAG, "normalizedPreviewToUi, w = " + w + ", h = " + h
                + ", orientation = " + displayOrientation
                + ", mirror = " + isMirror);
        coordinatesLog(TAG, "normalizedPreviewToUi, previewWidth = " + previewWidth
            + ", previewHeight = " + previewHeight);
        coordinatesLog(TAG, "normalizedPreviewToUi, rect = (" + rect.left + ", " + rect.top + ", "
                + rect.right + ", " + rect.bottom + ")");
        Matrix matrix = new Matrix();
        prepareMatrix(matrix, isMirror, displayOrientation, previewWidth, previewHeight);
        RectF rectf = new RectF(rect);
        matrix.mapRect(rectf);
        Rect resultRect = new Rect();
        rectf.round(resultRect);
        coordinatesLog(TAG, "normalizedPreviewToUi, result_rect = (" + resultRect.left + ", "
                + resultRect.top + ", "
                + resultRect.right + ", " + resultRect.bottom + ")");
        return resultRect;
    }

private static void prepareMatrix(Matrix matrix, boolean mirror, int displayOrientation,
                                      int viewWidth, int viewHeight) {
        // Need mirror for front camera.
        matrix.setScale(mirror ? -1 : 1, 1);
        // This is the value for android.hardware.Camera.setDisplayOrientation.
        matrix.postRotate(90 /*displayOrientation*/);
        // Camera driver coordinates range from (-1000, -1000) to (1000, 1000).
        // UI coordinates range from (0, 0) to (width, height).
        // matrix.postScale(viewWidth / 2000f, viewHeight / 2000f);
        //cczheng change displayOrientation 0 to 90, scale 2000->2200 2000->1500
        matrix.postScale(viewWidth / 2200f, viewHeight / 1500f);
        matrix.postTranslate(viewWidth / 2f, viewHeight / 2f);
    }

录像相关

经过上面的调整，录像预览时方向是对的，但保存的视频播放时依旧是竖屏的，这么说我们还需要进一步修改。

通过搜索发现设置录像参数时 mMediaRecorder.setOrientationHint() 就是控制保存视频的成像方向。

整个工程搜索找到

./common/src/com/mediatek/camera/common/mode/video/recorder/NormalRecorder.java:        mMediaRecorder.setOrientationHint(spec.orientationHint);

通过打印日志发现 orientationHint 果然为 0,竖屏，那么我们只需将 orientationHint 改为 90 应该就能为横屏

2019-11-21 08:30:09.601 3937-3937/com.mediatek.camera D/CamAp_VideoHelper: [getVideoTempPath] mTempPath = /storage/emulated/0/DCIM/Camera/.videorecorder.3gp.tmp
2019-11-21 08:30:09.648 3937-3937/com.mediatek.camera D/CamAp_NormalRecorder: [init]   filePath = /storage/emulated/0/DCIM/Camera/.videorecorder.3gp.tmp  spec.captureRate = 0  spec.videoFrameRate = 0  spec.orientationHint = 0  spec.profile.videoFrameRate = 30  spec.profile.videoFrameWidth = 1280  spec.profile.videoFrameHeight = 720

接下来简单跟踪下初始化配置参数的过程

common\src\com\mediatek\camera\common\mode\video\VideoMode.java

initRecorder() 创建 NormalRecorder 对象，并开始初始化 init，需要传递 RecorderSpec 对象(包含很多录像相关参数的 bean)

通过自身 configRecorderSpec() 创建，最终调用到 VideoHelper 的 configRecorderSpec()

protected boolean initRecorder(boolean isStartRecording) {
        LogHelper.d(TAG, "[initRecorder]");
        releaseRecorder();
        mRecorder = new NormalRecorder();
        try {
            mRecorder.init(configRecorderSpec(isStartRecording));
            setMediaRecorderParameters();
            initForHal3(isStartRecording);
        } catch (RuntimeException e) {
            e.printStackTrace();
            releaseRecorder();
            return false;
        }
        return true;
    }

private IRecorder.RecorderSpec configRecorderSpec(boolean isStartRecording) {
        IRecorder.RecorderSpec recorderSpec = mVideoHelper.configRecorderSpec(
                getProfile(), mCameraId, mCameraApi, mSettingManager);
        mOrientationHint = recorderSpec.orientationHint;
        recorderSpec.infoListener = mOnInfoListener;
        recorderSpec.errorListener = mOnErrorListener;
        recorderSpec.releaseListener = mOnInfoListener;
        recorderSpec = modifyRecorderSpec(recorderSpec, isStartRecording);
        return recorderSpec;
    }

configRecorderSpec() 中新建一个内部类对象 RecorderSpec，依次给各个 public 字段赋值，默认指定使用 CameraApi.API2

所以获取 orientationHint 走的如下带 CameraCharacteristics 参数的 getRecordingRotation() 方法

由于我们的设备没有重力传感器，mApp.getGSensorOrientation() 一直是 -1，也就是 ORIENTATION_UNKNOWN

所以最终 rotation = sensorOrientation，打印 sensorOrientation 为 0，也就符合上面说的 orientationHint 果然为 0

当然你也可以在这里修改 getRecordingRotation() 返回值也能达到一样的效果

common\src\com\mediatek\camera\common\mode\video\VideoHelper.java

public IRecorder.RecorderSpec configRecorderSpec(CamcorderProfile profile, String cameraId,
                CameraDeviceManagerFactory.CameraApi api, ISettingManager settingManager) {
        sProfile = profile;
        IRecorder.RecorderSpec recorderSpec = new IRecorder.RecorderSpec();
        if (mCameraDevice.getCamera() != null) {
            mCameraDevice.unLockCamera();
            recorderSpec.camera = mCameraDevice.getCamera().getCamera();
        }
        if (api == CameraDeviceManagerFactory.CameraApi.API1) {
            recorderSpec.videoSource = MediaRecorder.VideoSource.CAMERA;
            recorderSpec.orientationHint = getRecordingRotation(mApp.getGSensorOrientation(),
                    mCameraDevice.getCameraInfo(Integer.parseInt(cameraId)));
        } else {
            recorderSpec.videoSource = MediaRecorder.VideoSource.SURFACE;
            recorderSpec.orientationHint = getRecordingRotation(mApp.getGSensorOrientation(),
                    getCameraCharacteristics(mApp.getActivity(), cameraId));
        }
        if (VALUE_ON.equals(settingManager.getSettingController().queryValue("key_microphone"))) {
            recorderSpec.isRecordAudio = true;
            recorderSpec.audioSource = MediaRecorder.AudioSource.CAMCORDER;
        } else {
            recorderSpec.isRecordAudio = false;
        }
        recorderSpec.profile = sProfile;
        recorderSpec.maxDurationMs = 0;
        recorderSpec.maxFileSizeBytes = getRecorderMaxSize();
        recorderSpec.location = mCameraContext.getLocation();
        recorderSpec.outFilePath = getVideoTempPath();
        return recorderSpec;
    }

public static int getRecordingRotation(int orientation, CameraCharacteristics characteristics) {
        int rotation = -1;
        int sensorOrientation = characteristics.get(CameraCharacteristics.SENSOR_ORIENTATION);
        boolean facingFront = characteristics.get(CameraCharacteristics.LENS_FACING)
                == CameraCharacteristics.LENS_FACING_FRONT;
        if (orientation != OrientationEventListener.ORIENTATION_UNKNOWN) {
            if (facingFront) {
                rotation = (sensorOrientation - orientation + 360) % 360;
            } else {
                rotation = (sensorOrientation + orientation) % 360;
            }
        } else {
            rotation = sensorOrientation;
        }
        LogHelper.e(TAG, "[getRecordingRotation] orientation = " +
                orientation + " sensorOrientation = " + sensorOrientation + " rotation = "  + rotation);
        return rotation;
    }

APP 应用参考文章

Android Camera2 API和拍照与录像过程

Android Camera2教程之打开相机、开启预览、实现PreviewCallback、拍照