这篇文章主要介绍分别采用Camera1、Camera2、CameraX API接口获取Camera数据流，并集成ArcSoft人脸识别算法。

ArcSoft官方的demo是采用的Camera1接口，我前面也写过一篇单独Camera2 接口集成Arcsoft接口的文章（全网首发：Android Camera2 集成人脸识别算法）

01应用设计流程图

如下图所示，应用流程比较简单，分别从不同的API接口获取到Camera数据流数据，然后送到ArcSoft人脸识别算法库中进行识别，最终将识别结果绘制到界面上。

02应用界面

CameraX需要和界面生命周期进行绑定，所以主界面设计成了2个Button入口，一个入口是Camera1和Camera2共用，一个是CameraX独立的入口。

如下图所示：Camera1和Camera2之间可以互相切换。


CameraX是单独的界面。

03代码实现

1） Camera1 API的使用：

private void startCameraByApi1() {
        DisplayMetrics metrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(metrics);
        CameraListener cameraListener = new CameraListener() {
            @Override
            public void onCameraOpened(Camera camera, int cameraId, int displayOrientation, boolean isMirror) {
                Camera.Size previewSize = camera.getParameters().getPreviewSize();
                mPreviewSize = new Size(previewSize.width,previewSize.height);
                drawHelper = new DrawHelper(previewSize.width, previewSize.height, previewView.getWidth(), previewView.getHeight(), displayOrientation
                        , cameraId, isMirror, false, false);
            }

            @Override
            public void onPreview(byte[] nv21, Camera camera) {
                drawFaceInfo(nv21);
            }

            @Override
            public void onCameraClosed() {
            }

            @Override
            public void onCameraError(Exception e) {
            }

            @Override
            public void onCameraConfigurationChanged(int cameraID, int displayOrientation) {
                if (drawHelper != null) {
                    drawHelper.setCameraDisplayOrientation(displayOrientation);
                }
            }
        };

        cameraAPI1Helper = new Camera1ApiHelper.Builder()
                .previewViewSize(new Point(previewView.getMeasuredWidth(), previewView.getMeasuredHeight()))
                .rotation(getWindowManager().getDefaultDisplay().getRotation())
                .specificCameraId(Camera.CameraInfo.CAMERA_FACING_BACK)
                .isMirror(false)
                .previewOn(previewView)
                .cameraListener(cameraListener)
                .build();
        cameraAPI1Helper.init();
        cameraAPI1Helper.start();
    }

2） Camera2 API的使用：

private void openCameraApi2(int width, int height) {
        Log.v(TAG, "---- openCameraAPi2();width: " + width + ";height: " + height);

        setUpCameraOutputs(width, height);
        CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
        try {
            if (!mCameraOpenCloseLock.tryAcquire(2500, TimeUnit.MILLISECONDS)) {
                throw new RuntimeException("Time out waiting to lock back camera opening.");
            }
            manager.openCamera(mCameraId, mStateCallback, mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            throw new RuntimeException("Interrupted while trying to lock camera opening.", e);
        }
    }

private final CameraDevice.StateCallback mStateCallback = new CameraDevice.StateCallback() {
        @Override
        public void onOpened(@NonNull CameraDevice cameraDevice) {
            initArcsoftDrawHelper();

            mCameraOpenCloseLock.release();
            mCameraDevice = cameraDevice;

            try {
                Thread.sleep(500);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            createCameraPreviewSession();
        }

        @Override
        public void onDisconnected(@NonNull CameraDevice cameraDevice) {
            mCameraOpenCloseLock.release();
            cameraDevice.close();
            mCameraDevice = null;
        }

        @Override
        public void one rror(@NonNull CameraDevice cameraDevice, int error) {
            mCameraOpenCloseLock.release();
            cameraDevice.close();
            mCameraDevice = null;
            finish();
        }
    };

private void createCameraPreviewSession() {
        try {
            SurfaceTexture texture = previewView.getSurfaceTexture();
            assert texture != null;

            // We configure the size of default buffer to be the size of camera preview we want.
            texture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());

            // This is the output Surface we need to start preview.
            Surface surface = new Surface(texture);

            mPreviewRequestBuilder
                    = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);

            mPreviewRequestBuilder.addTarget(surface);
            mPreviewRequestBuilder.addTarget(mImageReader.getSurface());

            mCameraDevice.createCaptureSession(Arrays.asList(surface, mImageReader.getSurface()),
                    new CameraCaptureSession.StateCallback() {

                        @Override
                        public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
                            Log.v(TAG, "--- Camera2API:onConfigured();");

                            if (null == mCameraDevice) {
                                return;
                            }

                            mPreviewCaptureSession = cameraCaptureSession;
                            try {
                                mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,
                                        CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);

                                mPreviewRequest = mPreviewRequestBuilder.build();
                                mPreviewCaptureSession.setRepeatingRequest(mPreviewRequest,
                                        null, mBackgroundHandler);
                            } catch (CameraAccessException e) {
                                e.printStackTrace();
                            }
                        }

                        @Override
                        public void onConfigureFailed(
                                @NonNull CameraCaptureSession cameraCaptureSession) {
                            showToast("Failed");
                        }
                    }, null
            );
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

private final ImageReader.OnImageAvailableListener mOnImageAvailableListener
            = new ImageReader.OnImageAvailableListener() {

        @Override
        public void onImageAvailable(ImageReader reader) {
            Image image = reader.acquireLatestImage();

            if(image == null){
                return;
            }

            synchronized (mImageReaderLock) {
                if(!mImageReaderLock.equals(1)){
                    Log.v(TAG, "--- image not available,just return!!!");
                    image.close();
                    return;
                }
                if (ImageFormat.YUV_420_888 == image.getFormat()) {
                    Image.Plane[] planes = image.getPlanes();

                    lock.lock();
                    if (y == null) {
                        y = new byte[planes[0].getBuffer().limit() - planes[0].getBuffer().position()];
                        u = new byte[planes[1].getBuffer().limit() - planes[1].getBuffer().position()];
                        v = new byte[planes[2].getBuffer().limit() - planes[2].getBuffer().position()];
                    }

                    if (image.getPlanes()[0].getBuffer().remaining() == y.length) {
                        planes[0].getBuffer().get(y);
                        planes[1].getBuffer().get(u);
                        planes[2].getBuffer().get(v);

                        if (nv21 == null) {
                            nv21 = new byte[planes[0].getRowStride() * mPreviewSize.getHeight() * 3 / 2];
                        }

                        if(nv21 != null && (nv21.length != planes[0].getRowStride() * mPreviewSize.getHeight() *3/2)){
                            return;
                        }

                        // 回传数据是YUV422
                        if (y.length / u.length == 2) {
                            ImageUtil.yuv422ToYuv420sp(y, u, v, nv21, planes[0].getRowStride(), mPreviewSize.getHeight());
                        }
                        // 回传数据是YUV420
                        else if (y.length / u.length == 4) {
                            ImageUtil.yuv420ToYuv420sp(y, u, v, nv21, planes[0].getRowStride(), mPreviewSize.getHeight());
                        }

                        //调用Arcsoft算法,绘制人脸信息
                        drawFaceInfo(nv21);
                    }
                    lock.unlock();
                }
            }
            image.close();
        }
    };

3） CameraX API的使用：

private void startCameraX() {
        Log.v(TAG,"--- startCameraX();");
        mPreviewSize = new Size(640,480);
        setPreviewViewAspectRatio();
        initArcsoftDrawHelper();

        Rational rational = new Rational(mPreviewSize.getHeight(), mPreviewSize.getWidth());
        // 1. preview
        PreviewConfig previewConfig = new PreviewConfig.Builder()
                .setTargetAspectRatio(rational)
                .setTargetResolution(mPreviewSize)
                .build();

        Preview preview = new Preview(previewConfig);
        preview.setOnPreviewOutputUpdateListener(new Preview.OnPreviewOutputUpdateListener() {
            @Override
            public void onUpdated(Preview.PreviewOutput output) {
                previewView.setSurfaceTexture(output.getSurfaceTexture());
                configureTransform(previewView.getWidth(),previewView.getHeight());
            }
        });

        // 2. capture
        ImageCaptureConfig imageCaptureConfig = new ImageCaptureConfig.Builder()
                .setTargetAspectRatio(rational)
                .setCaptureMode(ImageCapture.CaptureMode.MIN_LATENCY)
                .build();
        final ImageCapture imageCapture = new ImageCapture(imageCaptureConfig);

        // 3. analyze
        HandlerThread handlerThread = new HandlerThread("Analyze-thread");
        handlerThread.start();

        ImageAnalysisConfig imageAnalysisConfig = new ImageAnalysisConfig.Builder()
                .setCallbackHandler(new Handler(handlerThread.getLooper()))
                .setImageReaderMode(ImageAnalysis.ImageReaderMode.ACQUIRE_LATEST_IMAGE)
                .setTargetAspectRatio(rational)
                .setTargetResolution(mPreviewSize)
                .build();

        ImageAnalysis imageAnalysis = new ImageAnalysis(imageAnalysisConfig);
        imageAnalysis.setAnalyzer(new MyAnalyzer());

        CameraX.bindToLifecycle(this, preview, imageCapture, imageAnalysis);
    }

private class MyAnalyzer implements ImageAnalysis.Analyzer {
        private byte[] y;
        private byte[] u;
        private byte[] v;
        private byte[] nv21;
        private ReentrantLock lock = new ReentrantLock();
        private Object mImageReaderLock = 1;//1 available,0 unAvailable

        @Override
        public void analyze(ImageProxy imageProxy, int rotationDegrees) {
            Image image =  imageProxy.getImage();

            if(image == null){
                return;
            }

            synchronized (mImageReaderLock) {
                if(!mImageReaderLock.equals(1)){
                    image.close();
                    return;
                }
                if (ImageFormat.YUV_420_888 == image.getFormat()) {
                    Image.Plane[] planes = image.getPlanes();
                    if(mImageReaderSize == null){
                        mImageReaderSize = new Size(planes[0].getRowStride(),image.getHeight());
                    }

                    lock.lock();
                    if (y == null) {
                        y = new byte[planes[0].getBuffer().limit() - planes[0].getBuffer().position()];
                        u = new byte[planes[1].getBuffer().limit() - planes[1].getBuffer().position()];
                        v = new byte[planes[2].getBuffer().limit() - planes[2].getBuffer().position()];
                    }

                    if (image.getPlanes()[0].getBuffer().remaining() == y.length) {
                        planes[0].getBuffer().get(y);
                        planes[1].getBuffer().get(u);
                        planes[2].getBuffer().get(v);

                        if (nv21 == null) {
                            nv21 = new byte[planes[0].getRowStride() * image.getHeight() * 3 / 2];
                        }

                        if(nv21 != null && (nv21.length != planes[0].getRowStride() * image.getHeight() *3/2)){
                            return;
                        }

                        // 回传数据是YUV422
                        if (y.length / u.length == 2) {
                            ImageUtil.yuv422ToYuv420sp(y, u, v, nv21, planes[0].getRowStride(), image.getHeight());
                        }
                        // 回传数据是YUV420
                        else if (y.length / u.length == 4) {
                            nv21 = ImageUtil.yuv420ToNv21(image);
                        }

                        //调用Arcsoft算法,绘制人脸信息
                        drawFaceInfo(nv21,mPreviewSize);
                    }
                    lock.unlock();
                }
            }
        }
    }

04遇到的问题

1）预览变形

这个是由于设置Camera预览的size和TextureView的size比例不一致导致。

我们一般会根据当前设备屏幕的size,遍历camera支持的preview size，找到适合当前设备的预览size，再根据当前预览size，动态调整textureView的显示。

2）Arcsoft Sdk Error 异常

中间遇到的关于Arcsoft sdk error异常的，可以在Arcsoft开发中心，帮助界面，输入对应的error code，根据提示信息，可以帮助我们快速定位排查问题。

05附录

1）Demo地址：

公众号:小驰笔记，回复：人脸识别，即可获取代码下载地址。

2） Arcsoft官网sdk下载地址：

 https://ai.arcsoft.com.cn/

了解更多人脸识别产品相关内容请到虹软视觉开放平台哦