Question

我一直在努力使用Android Camera2 API。我找到了一个帮助我实现这个的教程。但我有两个主要问题。

首先，当我捕获并映像并将其保存到设备存储时，我收到以下消息： W / ImageReader_JNI：无法获取缓冲项，很可能客户端尝试获取超过maxImages缓冲区和 BufferItemConsumer：[ImageReader-1280x720f100m1-6149-0]无法释放缓冲区：未知错误-1（1）。
所以也许我忘记释放一些记忆或某种程度。

其次，当我离开应用程序并回到它时，我得到了这个： E / CameraCaptureSession：会话2：停止重复时出现异常： android.hardware.camera2.CameraAccessException：CAMERA_DISCONNECTED（2）：checkPidStatus：1442：摄像头设备已断开连接在android.hardware.camera2.CameraManager.throwAsPublicException（CameraManager.java:658）。

对于第二个问题，我认为我的相机初始化有问题，好像它试过了每次我恢复时初始化。

package com.picchase.android.picchase;

import android.content.Context;
import android.content.pm.PackageManager;
import android.graphics.ImageFormat;
import android.graphics.SurfaceTexture;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.CameraCaptureSession;
import android.hardware.camera2.CameraCharacteristics;
import android.hardware.camera2.CameraDevice;
import android.hardware.camera2.CameraManager;
import android.hardware.camera2.CameraMetadata;
import android.hardware.camera2.CaptureRequest;
import android.hardware.camera2.TotalCaptureResult;
import android.hardware.camera2.params.StreamConfigurationMap;
import android.media.Image;
import android.media.ImageReader;
import android.os.Environment;
import android.os.Handler;
import android.os.HandlerThread;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Size;
import android.util.SparseIntArray;
import android.view.Surface;
import android.view.TextureView;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import android.Manifest;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.UUID;

public class MainActivity extends AppCompatActivity {

    // Used to load the 'native-lib' library on application startup.
    static {
        System.loadLibrary("native-lib");
    }

    private Button btnCapture;
    private TextureView textureView;

    // Check state orientation of output image
    private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
    static {
        ORIENTATIONS.append(Surface.ROTATION_0, 90);
        ORIENTATIONS.append(Surface.ROTATION_90, 0);
        ORIENTATIONS.append(Surface.ROTATION_180, 270);
        ORIENTATIONS.append(Surface.ROTATION_270, 180);
    }

    private String cameraId;
    private CameraDevice cameraDevice;
    private CameraCaptureSession cameraCaptureSessions;
    private CaptureRequest.Builder captureRequestBuilder;
    private Size imageDimension;

    // Save to FILE
    private File file;
    private static final int REQUEST_CAMERA_PERMISSION = 1;
    private boolean mFlashSupported;
    private Handler mBackgroundHandler;
    private HandlerThread mBackgroundThread;

    CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {
        @Override
        public void onOpened(@NonNull CameraDevice camera) {
            cameraDevice = camera;
            createCameraPreview();
        }

        @Override
        public void onDisconnected(@NonNull CameraDevice cameraDevice) {
            cameraDevice.close();
        }

        @Override
        public void onError(@NonNull CameraDevice cameraDevice, int i) {
            cameraDevice.close();
            cameraDevice = null;
        }
    };

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

        // Example of a call to a native method
        /*TextView tv = (TextView) findViewById(R.id.sample_text);
        tv.setText(stringFromJNI());*/

        textureView = (TextureView)findViewById(R.id.textureView);
        assert textureView != null;
        textureView.setSurfaceTextureListener(textureListener);
        btnCapture = (Button)findViewById(R.id.btnCapture);
        btnCapture.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                takePicture();
            }
        });
    }

    private void takePicture() {
        if (cameraDevice == null) {
            return;
        }
        CameraManager manager = (CameraManager)getSystemService(Context.CAMERA_SERVICE);
        try {
            CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraDevice.getId());
            Size[] jpegSizes = null;
            if (characteristics != null) {
                jpegSizes = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP)
                        .getOutputSizes(ImageFormat.JPEG);

                // Capture image with custom size
                int width = 640;
                int height = 480;

                if (jpegSizes != null && jpegSizes.length > 0) {
                    width = jpegSizes[0].getWidth();
                    height = jpegSizes[0].getHeight();
                }
                final ImageReader reader = ImageReader.newInstance(width, height, ImageFormat.JPEG, 1);
                List<Surface> outputSurface = new ArrayList<>(2);
                outputSurface.add(reader.getSurface());
                outputSurface.add(new Surface(textureView.getSurfaceTexture()));

                final CaptureRequest.Builder captureBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
                captureBuilder.addTarget(reader.getSurface());
                captureBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);

                // Check orientation based on device
                int rotation = getWindowManager().getDefaultDisplay().getRotation();
                captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));

                file = new File(Environment.getExternalStorageDirectory() + "/" + UUID.randomUUID().toString() + ".jpg");
                ImageReader.OnImageAvailableListener readerListener = new ImageReader.OnImageAvailableListener() {
                    @Override
                    public void onImageAvailable(ImageReader imageReader) {
                        Image image = null;
                        try {
                            image = reader.acquireLatestImage();
                            ByteBuffer buffer = image.getPlanes()[0].getBuffer();
                            byte[] bytes = new byte[buffer.capacity()];
                            buffer.get(bytes);
                            save(bytes);
                        }
                        catch (FileNotFoundException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        } finally {
                            {
                                if (image != null) {
                                    image.close();
                                }
                            }
                        }
                    }
                    private void save(byte[] bytes) throws IOException {
                        OutputStream outputStream = null;
                        try {
                            outputStream = new FileOutputStream(file);
                            outputStream.write(bytes);
                        } finally {
                            if (outputStream != null) {
                                outputStream.close();
                            }
                        }
                    }
                };
                reader.setOnImageAvailableListener(readerListener, mBackgroundHandler);
                final CameraCaptureSession.CaptureCallback captureListener = new CameraCaptureSession.CaptureCallback() {
                    @Override
                    public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
                        super.onCaptureCompleted(session, request, result);
                        Toast.makeText(MainActivity.this, "Saved " + file, Toast.LENGTH_SHORT).show();
                        createCameraPreview();
                    }
                };

                cameraDevice.createCaptureSession(outputSurface, new CameraCaptureSession.StateCallback() {
                    @Override
                    public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
                        try {
                            cameraCaptureSession.capture(captureBuilder.build(), captureListener, mBackgroundHandler);
                        } catch (CameraAccessException e) {
                            e.printStackTrace();
                        }
                    }

                    @Override
                    public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {

                    }
                }, mBackgroundHandler);
            }

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

    private void createCameraPreview() {
        try {
            SurfaceTexture texture = textureView.getSurfaceTexture();
            assert texture != null;
            texture.setDefaultBufferSize(imageDimension.getWidth(), imageDimension.getHeight());
            Surface surface =  new Surface(texture);
            captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
            captureRequestBuilder.addTarget(surface);
            cameraDevice.createCaptureSession(Arrays.asList(surface), new CameraCaptureSession.StateCallback() {
                @Override
                public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
                    if (cameraDevice == null) {
                        return;
                    }
                    cameraCaptureSessions = cameraCaptureSession;
                    updatePreview();
                }

                @Override
                public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
                    Toast.makeText(MainActivity.this, "Changed", Toast.LENGTH_SHORT).show();
                }
            }, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    private void updatePreview() {
        if (cameraDevice == null) {
            Toast.makeText(this, "Error: Camera device is null", Toast.LENGTH_SHORT).show();
        }
        captureRequestBuilder.set(CaptureRequest.CONTROL_MODE, CaptureRequest.CONTROL_MODE_AUTO);
        try {
            cameraCaptureSessions.setRepeatingRequest(captureRequestBuilder.build(), null, mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    private void openCamera() {
        CameraManager manager = (CameraManager)getSystemService(Context.CAMERA_SERVICE);
        try {
            cameraId = manager.getCameraIdList()[0];
            CameraCharacteristics characteristics = manager .getCameraCharacteristics(cameraId);
            StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
            assert map != null;
            imageDimension = map.getOutputSizes(SurfaceTexture.class)[0];

            // Check realtime permission if run higher than API 23
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                ActivityCompat.requestPermissions(this, new String[]{
                        Manifest.permission.CAMERA,
                        Manifest.permission.WRITE_EXTERNAL_STORAGE
                }, REQUEST_CAMERA_PERMISSION);
                return;
            }
            manager.openCamera(cameraId, stateCallback, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    TextureView.SurfaceTextureListener textureListener = new TextureView.SurfaceTextureListener() {
        @Override
        public void onSurfaceTextureAvailable(SurfaceTexture surfaceTexture, int i, int i1) {
            openCamera();
        }

        @Override
        public void onSurfaceTextureSizeChanged(SurfaceTexture surfaceTexture, int i, int i1) {

        }

        @Override
        public boolean onSurfaceTextureDestroyed(SurfaceTexture surfaceTexture) {
            return false;
        }

        @Override
        public void onSurfaceTextureUpdated(SurfaceTexture surfaceTexture) {

        }
    };

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == REQUEST_CAMERA_PERMISSION) {
            if (grantResults[0] != PackageManager.PERMISSION_GRANTED) {
                Toast.makeText(this, "You can't use camera without permission", Toast.LENGTH_SHORT).show();
                finish();
            }
        }
    }

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

    @Override
    protected void onResume() {
        super.onResume();
        startBackgroundThread();
        if (textureView.isAvailable()) {
            openCamera();
        } else {
            textureView.setSurfaceTextureListener(textureListener);
        }
    }

    private void startBackgroundThread() {
        mBackgroundThread = new HandlerThread("Camera background");
        mBackgroundThread.start();
        mBackgroundHandler = new Handler(mBackgroundThread.getLooper());
    }

    private void stopBackgroundThread() {
        mBackgroundThread.quitSafely();
        try {
            mBackgroundThread.join();
            mBackgroundThread = null;
            mBackgroundHandler = null;
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    /**
     * A native method that is implemented by the 'native-lib' native library,
     * which is packaged with this application.
     */
    public native String stringFromJNI();
}

如果有人可以帮我清除它，那真的很棒。

Answer 1

当你的活动达到onPause（）时，你应该关闭cameraDevice。从那里简单地调用hot-folder可能就足够了，但为了安全起见，好的做法是拥有私有方法

cameraDevice.close()

并始终使用此方法关闭相机设备。

当您在@MainThread private void closeCameraDevice() { if (cameraDevice != null) { cameraDevice.close(); cameraDevice = null; } }或onDisconnected()回调中关闭cameraDevice时，请确保不在活动中留下未知参考，例如

onError()

Android Camera2 API缓冲区和相机断开连接问题

1 个答案: