问题
I need to capture multiple photos using Camera2 API after particular interval, say 5 seconds. I need to do it without preview. I am able to capture a single photo without preview, but I need to know how to capture multiple photos? Once the camera is opened, I don't want to set all parameters again and again, I just want to capture photos after particular interval and once all photos are captured, then I will close the camera.
Also only first time the image is getting captured. Second time when I call takepciture() method, nothing happens.
Below is my code.
Please help.
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.ImageFormat;
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.Build;
import android.os.Environment;
import android.os.Handler;
import android.os.HandlerThread;
import androidx.annotation.NonNull;
import android.util.Log;
import android.util.Size;
import android.widget.Toast;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Date;
import java.util.UUID;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import androidx.annotation.RequiresApi;
import androidx.core.content.ContextCompat;
@RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
public class CameraAdmin {
Context context;
private static final String TAG = "CameraAdmin";
private String mCameraId;
private CameraCaptureSession mCaptureSession;
private CameraDevice mCameraDevice;
private HandlerThread backgroundThread;
private ImageReader imageReader;
private String cImgType,cFileToSave;
public boolean CaptureCompleted;
CaptureRequest.Builder captureBuilder;
public CameraAdmin(Context context,String CameraID) {
this.context = context;
this.mCameraId=CameraID;
this.CaptureCompleted=false;
}
public void openCamera() {
if (ContextCompat.checkSelfPermission(context, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
return;
}
setUpCameraOutputs();
CameraManager manager = (CameraManager) context.getSystemService(Context.CAMERA_SERVICE);
try {
manager.openCamera(mCameraId, mStateCallback, null);
} catch (Exception e) {
e.printStackTrace();
}
}
private void setUpCameraOutputs() {
CameraManager manager = (CameraManager) context.getSystemService(Context.CAMERA_SERVICE);
try {
CameraCharacteristics characteristics = manager.getCameraCharacteristics(mCameraId);
StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
imageReader = ImageReader.newInstance(1920, 1080, ImageFormat.JPEG, /*maxImages*/2);
imageReader.setOnImageAvailableListener(mOnImageAvailableListener, null);
return;
} catch (CameraAccessException e) {
e.printStackTrace();
} catch (NullPointerException e) {
e.printStackTrace();
}
}
private final CameraDevice.StateCallback mStateCallback = new CameraDevice.StateCallback() {
@Override
public void onOpened(@NonNull CameraDevice cameraDevice) {
mCameraDevice = cameraDevice;
createCameraCaptureSession();
}
@Override
public void onDisconnected(@NonNull CameraDevice cameraDevice) {
cameraDevice.close();
mCameraDevice = null;
}
@Override
public void onError(@NonNull CameraDevice cameraDevice, int error) {
cameraDevice.close();
mCameraDevice = null;
}
};
private final ImageReader.OnImageAvailableListener mOnImageAvailableListener = new ImageReader.OnImageAvailableListener() {
@Override
public void onImageAvailable(ImageReader reader) {
Log.d(TAG, "ImageAvailable");
final Image image = reader.acquireLatestImage();
final ByteBuffer buffer = image.getPlanes()[0].getBuffer();
final byte[] bytes = new byte[buffer.capacity()];
buffer.get(bytes);
saveImageToDisk(bytes);
Intent intent = new Intent();
intent.setAction(MainActivity.MyBroadcastReceiver.ACTION);
intent.putExtra("dataToPass", "Image Saved!");
context.sendBroadcast(intent);
image.close();
}
};
private void saveImageToDisk(final byte[] bytes)
{
final File file = new File(Environment.getExternalStorageDirectory() + "/" + cFileToSave +".jpg");
try (final OutputStream output = new FileOutputStream(file)) {
output.write(bytes);
Log.d("FileSaved","FileSaved");
} catch (final IOException e) {
Log.e(TAG, "Exception occurred while saving picture to external storage ", e);
}
}
public void closeCamera() {
try {
if (null != mCaptureSession) {
mCaptureSession.close();
mCaptureSession = null;
}
if (null != mCameraDevice) {
mCameraDevice.close();
mCameraDevice = null;
}
if (null != imageReader) {
imageReader.close();
imageReader = null;
}
} catch (Exception e) {
throw new RuntimeException("Interrupted while trying to lock camera closing.", e);
} finally {
}
}
private void createCameraCaptureSession() {
try {
captureBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
captureBuilder.set(CaptureRequest.CONTROL_AE_EXPOSURE_COMPENSATION,-3);
captureBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
captureBuilder.set(CaptureRequest.CONTROL_AF_MODE, CaptureRequest.CONTROL_AF_MODE_AUTO);
captureBuilder.set(CaptureRequest.LENS_FOCUS_DISTANCE, 0f);
captureBuilder.addTarget(imageReader.getSurface());
mCameraDevice.createCaptureSession(Arrays.asList(imageReader.getSurface()),
new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
if (null == mCameraDevice) {
return;
}
mCaptureSession = cameraCaptureSession;
}
@Override
public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
Log.d(TAG, "Configuration Failed");
}
}, null
);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
public void takePicture(String ImgType,String FileToSave) {
try {
if (null == mCameraDevice) {
return;
}
this.cImgType = ImgType;
this.cFileToSave = FileToSave;
CameraCaptureSession.CaptureCallback CaptureCallback = new CameraCaptureSession.CaptureCallback() {
@Override
public void onCaptureCompleted(@NonNull CameraCaptureSession session, @NonNull CaptureRequest request, @NonNull TotalCaptureResult result) {
}
};
mCaptureSession.capture(captureBuilder.build(), CaptureCallback, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
Toast.makeText(context, file.getAbsolutePath(), Toast.LENGTH_SHORT).show();
}
}
回答1:
You'll need to configure a repeating request on the CameraCaptureSession object. Documentation for that is here: https://developer.android.com/reference/android/hardware/camera2/CameraCaptureSession.html#setRepeatingRequest(android.hardware.camera2.CaptureRequest,%20android.hardware.camera2.CameraCaptureSession.CaptureCallback,%20android.os.Handler)
来源：https://stackoverflow.com/questions/59026438/how-to-take-multiple-photos-without-preview-using-camera2-api-in-android