点击表格后，我通过插座从相机逐帧传输图像。我不明白如何在点击表格后不间断地传输图像。试图放入一个循环，但在这种情况下，表单上显示的图像挂起。怎么做对了？这是我工作的代码。
/**
* Called when the user clicks on our {@code SurfaceView}, which has ID {@code mainSurfaceView}
* as defined in the {@code mainactivity.xml} layout file. <p>Captures a full-resolution image
* and saves it to permanent storage.</p>
*/
public void onClickOnSurfaceView(View v) {
if (mCaptureSession != null) {
try {
CaptureRequest.Builder requester =
mCamera.createCaptureRequest(mCamera.TEMPLATE_STILL_CAPTURE);
requester.addTarget(mCaptureBuffer.getSurface());
try {
// This handler can be null because we aren't actually attaching any callback
mCaptureSession.capture(requester.build(), /*listener*/null, /*handler*/null);
} catch (CameraAccessException ex) {
Log.e(TAG, "Failed to file actual capture request", ex);
}
} catch (CameraAccessException ex) {
Log.e(TAG, "Failed to build actual capture request", ex);
}
} else {
Log.e(TAG, "User attempted to perform a capture outside our session");
}
// Control flow continues in mImageCaptureListener.onImageAvailable()
}
/**
* Callbacks invoked upon state changes in our {@code SurfaceView}.
*/
final SurfaceHolder.Callback mSurfaceHolderCallback = new SurfaceHolder.Callback() {
/** The camera device to use, or null if we haven't yet set a fixed surface size. */
private String mCameraId;
/** Whether we received a change callback after setting our fixed surface size. */
private boolean mGotSecondCallback;
@Override
public void surfaceCreated(SurfaceHolder holder) {
// This is called every time the surface returns to the foreground
Log.i(TAG, "Surface created");
mCameraId = null;
mGotSecondCallback = false;
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
Log.i(TAG, "Surface destroyed");
holder.removeCallback(this);
// We don't stop receiving callbacks forever because onResume() will reattach us
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
// On the first invocation, width and height were automatically set to the view's size
if (mCameraId == null) {
// Find the device's back-facing camera and set the destination buffer sizes
try {
for (String cameraId : mCameraManager.getCameraIdList()) {
CameraCharacteristics cameraCharacteristics =
mCameraManager.getCameraCharacteristics(cameraId);
if (cameraCharacteristics.get(cameraCharacteristics.LENS_FACING) ==
CameraCharacteristics.LENS_FACING_BACK) {
Log.i(TAG, "Found a back-facing camera");
StreamConfigurationMap info = cameraCharacteristics
.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
// Bigger is better when it comes to saving our image
Size largestSize = Collections.max(
Arrays.asList(info.getOutputSizes(ImageFormat.JPEG)),
new CompareSizesByArea());
// Prepare an ImageReader in case the user wants to capture images
Log.i(TAG, "Capture size: " + largestSize);
mCaptureBuffer = ImageReader.newInstance(640,
480, ImageFormat.JPEG, /*maxImages*/2);
mCaptureBuffer.setOnImageAvailableListener(
mImageCaptureListener, mBackgroundHandler);
Log.i(TAG, "SurfaceView size: " +
mSurfaceView.getWidth() + 'x' + mSurfaceView.getHeight());
Size optimalSize = chooseBigEnoughSize(
info.getOutputSizes(SurfaceHolder.class), width, height);
// Set the SurfaceHolder to use the camera's largest supported size
Log.i(TAG, "Preview size: " + optimalSize);
SurfaceHolder surfaceHolder = mSurfaceView.getHolder();
surfaceHolder.setFixedSize(optimalSize.getWidth(),
optimalSize.getHeight());
mCameraId = cameraId;
return;
}
}
} catch (CameraAccessException ex) {
Log.e(TAG, "Unable to list cameras", ex);
}
Log.e(TAG, "Didn't find any back-facing cameras");
// This is the second time the method is being invoked: our size change is complete
} else if (!mGotSecondCallback) {
if (mCamera != null) {
Log.e(TAG, "Aborting camera open because it hadn't been closed");
return;
}
// Open the camera device
try {
mCameraManager.openCamera(mCameraId, mCameraStateCallback,
mBackgroundHandler);
} catch (CameraAccessException ex) {
Log.e(TAG, "Failed to configure output surface", ex);
}
mGotSecondCallback = true;
// Control flow continues in mCameraStateCallback.onOpened()
}
}
};
/**
* Calledbacks invoked upon state changes in our {@code CameraDevice}. <p>These are run on
* {@code mBackgroundThread}.</p>
*/
final CameraDevice.StateCallback mCameraStateCallback =
new CameraDevice.StateCallback() {
@Override
public void onOpened(CameraDevice camera) {
Log.i(TAG, "Successfully opened camera");
mCamera = camera;
try {
List<Surface> outputs = Arrays.asList(
mSurfaceView.getHolder().getSurface(), mCaptureBuffer.getSurface());
camera.createCaptureSession(outputs, mCaptureSessionListener,
mBackgroundHandler);
} catch (CameraAccessException ex) {
Log.e(TAG, "Failed to create a capture session", ex);
}
// Control flow continues in mCaptureSessionListener.onConfigured()
}
@Override
public void onDisconnected(CameraDevice camera) {
Log.e(TAG, "Camera was disconnected");
}
@Override
public void onError(CameraDevice camera, int error) {
Log.e(TAG, "State error on device '" + camera.getId() + "': code " + error);
}
};
/**
* Callbacks invoked upon state changes in our {@code CameraCaptureSession}. <p>These are run on
* {@code mBackgroundThread}.</p>
*/
final CameraCaptureSession.StateCallback mCaptureSessionListener =
new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(CameraCaptureSession session) {
Log.i(TAG, "Finished configuring camera outputs");
mCaptureSession = session;
SurfaceHolder holder = mSurfaceView.getHolder();
if (holder != null) {
try {
// Build a request for preview footage
CaptureRequest.Builder requestBuilder =
mCamera.createCaptureRequest(mCamera.TEMPLATE_PREVIEW);
requestBuilder.addTarget(holder.getSurface());
CaptureRequest previewRequest = requestBuilder.build();
// Start displaying preview images
try {
session.setRepeatingRequest(previewRequest, /*listener*/null,
/*handler*/null);
} catch (CameraAccessException ex) {
Log.e(TAG, "Failed to make repeating preview request", ex);
}
} catch (CameraAccessException ex) {
Log.e(TAG, "Failed to build preview request", ex);
}
} else {
Log.e(TAG, "Holder didn't exist when trying to formulate preview request");
}
}
@Override
public void onClosed(CameraCaptureSession session) {
mCaptureSession = null;
}
@Override
public void onConfigureFailed(CameraCaptureSession session) {
Log.e(TAG, "Configuration error on device '" + mCamera.getId());
}
};
/**
* Callback invoked when we've received a JPEG image from the camera.
*/
final ImageReader.OnImageAvailableListener mImageCaptureListener =
new ImageReader.OnImageAvailableListener() {
@Override
public void onImageAvailable(ImageReader reader) {
// Save the image once we get a chance
mBackgroundHandler.post(new CapturedImageSaver(reader.acquireNextImage()));
}
};
static class CapturedImageSaver implements Runnable {
/**
* The image to save.
*/
private Image mCapture;
public CapturedImageSaver(Image capture) {
mCapture = capture;
}
@Override
public void run() {
try {
// Choose an unused filename under the Pictures/ directory
File file = File.createTempFile(CAPTURE_FILENAME_PREFIX, ".jpg",
Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES));
try (FileOutputStream ostream = new FileOutputStream(file)) {
Log.i(TAG, "Retrieved image is" +
(mCapture.getFormat() == ImageFormat.JPEG ? "" : "n't") + " a JPEG");
ByteBuffer buffer = mCapture.getPlanes()[0].getBuffer();
Log.i(TAG, "Captured image size: " +
mCapture.getWidth() + 'x' + mCapture.getHeight());
// Write the image out to the chosen file
byte[] jpeg = new byte[buffer.remaining()];
buffer.get(jpeg);
//ostream.write(jpeg);
//send image via socket
System.out.println(SERVER_IP);
InetAddress serverAddr = InetAddress.getByName(SERVER_IP);
System.out.println("Created serverAddr " + SERVER_IP);
Socket socket = new Socket(serverAddr, SERVER_PORT);
System.out.println("Socket created..");
System.out.println(mCapture.getWidth() + "^" + mCapture.getHeight());
try (DataOutputStream dOut = new DataOutputStream(socket.getOutputStream())) {
dOut.writeInt(jpeg.length);
dOut.write(jpeg);
dOut.flush();
}
} catch (FileNotFoundException ex) {
Log.e(TAG, "Unable to open output file for writing", ex);
} catch (IOException ex) {
Log.e(TAG, "Failed to write the image to the output file", ex);
}
} catch (IOException ex) {
Log.e(TAG, "Unable to create a new output file", ex);
} finally {
mCapture.close();
}
}
}
}
一些重制代码。该函数添加了一个调用，每隔170毫秒就会在定时器上接收一个快照。如果我设置的时间少于指定的时间，界面会挂起......有人可以告诉我该怎么做对吗？现在我每秒有5.88帧。我希望每秒至少达到15帧。
public void onClickOnSurfaceView(View v) {
int i = 0;
Timer myTimer = new Timer(); // Создаем таймер
final Handler uiHandler = new Handler();
myTimer.schedule(new TimerTask() { // Определяем задачу
@Override
public void run() {
uiHandler.post(new Runnable() {
@Override
public void run() {
if (mCaptureSession != null) {
//while(true){
try {
CaptureRequest.Builder requester =
mCamera.createCaptureRequest(mCamera.TEMPLATE_STILL_CAPTURE);
requester.addTarget(mCaptureBuffer.getSurface());
//while(i<20) {
try {
// This handler can be null because we aren't actually attaching any callback
mCaptureSession.capture(requester.build(), /*listener*/null, /*handler*/null);
} catch (CameraAccessException ex) {
Log.e(TAG, "Failed to file actual capture request", ex);
}
//}
} catch (CameraAccessException ex) {
Log.e(TAG, "Failed to build actual capture request", ex);
}
//}
} else {
Log.e(TAG, "User attempted to perform a capture outside our session");
}
}
});
};
}, 0L, 1L * 180); // интервал - 500 миллисекунд, 0 миллисекунд до первого запуска.
// Control flow continues in mImageCaptureListener.onImageAvailable()
}
我无法通过这种方式解决问题，所以我按照以下步骤进行操作：当我需要传输图像时，我从SurfaceView（屏幕截图）获取当前图片并通过套接字发送。