/*
* Copyright 2016 The TensorFlow Authors. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.tensorflow.demo;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.app.Fragment;
import android.content.Context;
import android.content.DialogInterface;
import android.content.res.Configuration;
import android.graphics.ImageFormat;
import android.graphics.Matrix;
import android.graphics.RectF;
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.CaptureRequest;
import android.hardware.camera2.CaptureResult;
import android.hardware.camera2.TotalCaptureResult;
import android.hardware.camera2.params.StreamConfigurationMap;
import android.media.ImageReader;
import android.media.ImageReader.OnImageAvailableListener;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;
import android.text.TextUtils;
import android.util.Size;
import android.util.SparseIntArray;
import android.view.LayoutInflater;
import android.view.Surface;
import android.view.TextureView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import org.tensorflow.demo.env.Logger;
import org.tensorflow.demo.R; // Explicit import needed for internal Google builds.
public class CameraConnectionFragment extends Fragment {
private static final Logger LOGGER = new Logger();
/**
* The camera preview size will be chosen to be the smallest frame by pixel size capable of
* containing a DESIRED_SIZE x DESIRED_SIZE square.
*/
private static final int MINIMUM_PREVIEW_SIZE = 320;
/**
* Conversion from screen rotation to JPEG orientation.
*/
private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
private static final String FRAGMENT_DIALOG = "dialog";
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);
}
/**
* {@link android.view.TextureView.SurfaceTextureListener} handles several lifecycle events on a
* {@link TextureView}.
*/
private final TextureView.SurfaceTextureListener surfaceTextureListener =
new TextureView.SurfaceTextureListener() {
@Override
public void onSurfaceTextureAvailable(
final SurfaceTexture texture, final int width, final int height) {
openCamera(width, height);
}
@Override
public void onSurfaceTextureSizeChanged(
final SurfaceTexture texture, final int width, final int height) {
configureTransform(width, height);
}
@Override
public boolean onSurfaceTextureDestroyed(final SurfaceTexture texture) {
return true;
}
@Override
public void onSurfaceTextureUpdated(final SurfaceTexture texture) {}
};
/**
* Callback for Activities to use to initialize their data once the
* selected preview size is known.
*/
public interface ConnectionCallback {
void onPreviewSizeChosen(Size size, int cameraRotation);
}
/**
* ID of the current {@link CameraDevice}.
*/
private String cameraId;
/**
* An {@link AutoFitTextureView} for camera preview.
*/
private AutoFitTextureView textureView;
/**
* A {@link CameraCaptureSession } for camera preview.
*/
private CameraCaptureSession captureSession;
/**
* A reference to the opened {@link CameraDevice}.
*/
private CameraDevice cameraDevice;
/**
* The rotation in degrees of the camera sensor from the display.
*/
private Integer sensorOrientation;
/**
* The {@link android.util.Size} of camera preview.
*/
private Size previewSize;
/**
* {@link android.hardware.camera2.CameraDevice.StateCallback}
* is called when {@link CameraDevice} changes its state.
*/
private final CameraDevice.StateCallback stateCallback =
new CameraDevice.StateCallback() {
@Override
public void onOpened(final CameraDevice cd) {
// This method is called when the camera is opened. We start camera preview here.
cameraOpenCloseLock.release();
cameraDevice = cd;
createCameraPreviewSession();
}
@Override
public void onDisconnected(final CameraDevice cd) {
cameraOpenCloseLock.release();
cd.close();
cameraDevice = null;
}
@Override
public void onError(final CameraDevice cd, final int error) {
cameraOpenCloseLock.release();
cd.close();
cameraDevice = null;
final Activity activity = getActivity();
if (null != activity) {
activity.finish();
}
}
};
/**
* An additional thread for running tasks that shouldn't block the UI.
*/
private HandlerThread backgroundThread;
/**
* A {@link Handler} for running tasks in the background.
*/
private Handler backgroundHandler;
/**
* An {@link ImageReader} that handles preview frame capture.
*/
private ImageReader previewReader;
/**
* {@link android.hardware.camera2.CaptureRequest.Builder} for the camera preview
*/
private CaptureRequest.Builder previewRequestBuilder;
/**
* {@link CaptureRequest} generated by {@link #previewRequestBuilder}
*/
private CaptureRequest previewRequest;
/**
* A {@link Semaphore} to prevent the app from exiting before closing the camera.
*/
private final Semaphore cameraOpenCloseLock = new Semaphore(1);
/**
* A {@link OnImageAvailableListener} to receive frames as they are available.
*/
private final OnImageAvailableListener imageListener;
/** The input size in pixels desired by TensorFlow (width and height of a square bitmap). */
private final Size inputSize;
/**
* The layout identifier to inflate for this Fragment.
*/
private final int layout;
private final ConnectionCallback cameraConnectionCallback;
private CameraConnectionFragment(
final ConnectionCallback connectionCallback,
final OnImageAvailableListener imageListener,
final int layout,
final Size inputSize) {
this.cameraConnectionCallback = connectionCallback;
this.imageListener = imageListener;
this.layout = layout;
this.inputSize = inputSize;
}
/**
* Shows a {@link Toast} on the UI thread.
*
* @param text The message to show
*/
private void showToast(final String text) {
final Activity activity = getActivity();
if (activity != null) {
activity.runOnUiThread(
new Runnable() {
@Override
public void run() {
Toast.makeText(activity, text, Toast.LENGTH_SHORT).show();
}
});
}
}
/**
* Given {@code choices} of {@code Size}s supported by a camera, chooses the smallest one whose
* width and height are at least as large as the minimum of both, or an exact match if possible.
*
* @param choices The list of sizes that the camera supports for the intended output class
* @param width The minimum desired width
* @param height The minimum desired height
* @return The optimal {@code Size}, or an arbitrary one if none were big enough
*/
protected static Size chooseOptimalSize(final Size[] choices, final int width, final int height) {
final int minSize = Math.max(Math.min(width, height), MINIMUM_PREVIEW_SIZE);
final Size desiredSize = new Size(width, height);
// Collect the supported resolutions that are at least as big as the preview Surface
boolean exactSizeFound = false;
final List<Size> bigEnough = new ArrayList<Size>();
final List<Size> tooSmall = new ArrayList<Size>();
for (final Size option : choices) {
if (option.equals(desiredSize)) {
// Set the size but don't return yet so that remaining sizes will still be logged.
exactSizeFound = true;
}
if (option.getHeight() >= minSize && option.getWidth() >= minSize) {
bigEnough.add(option);
} else {
tooSmall.add(option);
}
}
LOGGER.i("Desired size: " + desiredSize + ", min size: " + minSize + "x" + minSize);
LOGGER.i("Valid preview sizes: [" + TextUtils.join(", ", bigEnough) + "]");
LOGGER.i("Rejected preview sizes: [" + TextUtils.join(", ", tooSmall) + "]");
if (exactSizeFound) {
LOGGER.i("Exact size match found.");
return desiredSize;
}
// Pick the smallest of those, assuming we found any
if (bigEnough.size() > 0) {
final Size chosenSize = Collections.min(bigEnough, new CompareSizesByArea());
LOGGER.i("Chosen size: " + chosenSize.getWidth() + "x" + chosenSize.getHeight());
return chosenSize;
} else {
LOGGER.e("Couldn't find any suitable preview size");
return choices[0];
}
}
public static CameraConnectionFragment newInstance(
final ConnectionCallback callback,
final OnImageAvailableListener imageListener,
final int layout,
final Size inputSize) {
return new CameraConnectionFragment(callback, imageListener, layout, inputSize);
}
@Override
public View onCreateView(
final LayoutInflater inflater, final ViewGroup container, final Bundle savedInstanceState) {
return inflater.inflate(layout, container, false);
}
@Override
public void onViewCreated(final View view, final Bundle savedInstanceState) {
textureView = (AutoFitTextureView) view.findViewById(R.id.texture);
}
@Override
public void onActivityCreated(final Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
@Override
public void onResume() {
super.onResume();
startBackgroundThread();
// When the screen is turned off and turned back on, the SurfaceTexture is already
// available, and "onSurfaceTextureAvailable" will not be called. In that case, we can open
// a camera and start preview from here (otherwise, we wait until the surface is ready in
// the SurfaceTextureListener).
if (textureView.isAvailable()) {
openCamera(textureView.getWidth(), textureView.getHeight());
} else {
textureView.setSurfaceTextureListener(surfaceTextureListener);
}
}
@Override
public void onPause() {
closeCamera();
stopBackgroundThread();
super.onPause();
}
public void setCamera(String cameraId) {
this.cameraId = cameraId;
}
/**
* Sets up member variables related to camera.
*/
private void setUpCameraOutputs() {
final Activity activity = getActivity();
final CameraManager manager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);
try {
final CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
final StreamConfigurationMap map =
characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
// For still image captures, we use the largest available size.
final Size largest =
Collections.max(
Arrays.asList(map.getOutputSizes(ImageFormat.YUV_420_888)),
new CompareSizesByArea());
sensorOrientation = characteristics.get(CameraCharacteristics.SENSOR_ORIENTATION);
// Danger, W.R.! Attempting to use too large a preview size could exceed the camera
// bus' bandwidth limitation, resulting in gorgeous previews but the storage of
// garbage capture data.
previewSize =
chooseOptimalSize(map.getOutputSizes(SurfaceTexture.class),
inputSize.getWidth(),
inputSize.getHeight());
// We fit the aspect ratio of TextureView to the size of preview we picked.
final int orientation = getResources().getConfiguration().orientation;
if (orientation == Configuration.ORIENTATION_LANDSCAPE) {
textureView.setAspectRatio(previewSize.getWidth(), previewSize.getHeight());
} else {
textureView.setAspectRatio(previewSize.getHeight(), previewSize.getWidth());
}
} catch (final CameraAccessException e) {
LOGGER.e(e, "Exception!");
} catch (final NullPointerException e) {
// Currently an NPE is thrown when the Camera2API is used but not supported on the
// device this code runs.
// TODO(andrewharp): abstract ErrorDialog/RuntimeException handling out into new method and
// reuse throughout app.
ErrorDialog.newInstance(getString(R.string.camera_error))
.show(getChildFragmentManager(), FRAGMENT_DIALOG);
throw new RuntimeException(getString(R.string.camera_error));
}
cameraConnectionCallback.onPreviewSizeChosen(previewSize, sensorOrientation);
}
/**
* Opens the camera specified by {@link CameraConnectionFragment#cameraId}.
*/
private void openCamera(final int width, final int height) {
setUpCameraOutputs();
configureTransform(width, height);
final Activity activity = getActivity();
final CameraManager manager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);
try {
if (!cameraOpenCloseLock.tryAcquire(2500, TimeUnit.MILLISECONDS)) {
throw new RuntimeException("Time out waiting to lock camera opening.");
}
manager.openCamera(cameraId, stateCallback, backgroundHandler);
} catch (final CameraAccessException e) {
LOGGER.e(e, "Exception!");
} catch (final InterruptedException e) {
throw new RuntimeException("Interrupted while trying to lock camera opening.", e);
}
}
/**
* Closes the current {@link CameraDevice}.
*/
private void closeCamera() {
try {
cameraOpenCloseLock.acquire();
if (null != captureSession) {
captureSession.close();
captureSession = null;
}
if (null != cameraDevice) {
cameraDevice.close();
cameraDevice = null;
}
if (null != previewReader) {
previewReader.close();
previewReader = null;
}
} catch (final InterruptedException e) {
throw new RuntimeException("Interrupted while trying to lock camera closing.", e);
} finally {
cameraOpenCloseLock.release();
}
}
/**
* Starts a background thread and its {@link Handler}.
*/
private void startBackgroundThread() {
backgroundThread = new HandlerThread("ImageListener");
backgroundThread.start();
backgroundHandler = new Handler(backgroundThread.getLooper());
}
/**
* Stops the background thread and its {@link Handler}.
*/
private void stopBackgroundThread() {
backgroundThread.quitSafely();
try {
backgroundThread.join();
backgroundThread = null;
backgroundHandler = null;
} catch (final InterruptedException e) {
LOGGER.e(e, "Exception!");
}
}
private final CameraCaptureSession.CaptureCallback captureCallback =
new CameraCaptureSession.CaptureCallback() {
@Override
public void onCaptureProgressed(
final CameraCaptureSession session,
final CaptureRequest request,
final CaptureResult partialResult) {}
@Override
public void onCaptureCompleted(
final CameraCaptureSession session,
final CaptureRequest request,
final TotalCaptureResult result) {}
};
/**
* Creates a new {@link CameraCaptureSession} for camera preview.
*/
private void createCameraPreviewSession() {
try {
final SurfaceTexture texture = textureView.getSurfaceTexture();
assert texture != null;
// We configure the size of default buffer to be the size of camera preview we want.
texture.setDefaultBufferSize(previewSize.getWidth(), previewSize.getHeight());
// This is the output Surface we need to start preview.
final Surface surface = new Surface(texture);
// We set up a CaptureRequest.Builder with the output Surface.
previewRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
previewRequestBuilder.addTarget(surface);
LOGGER.i("Opening camera preview: " + previewSize.getWidth() + "x" + previewSize.getHeight());
// Create the reader for the preview frames.
previewReader =
ImageReader.newInstance(
previewSize.getWidth(), previewSize.getHeight(), ImageFormat.YUV_420_888, 2);
previewReader.setOnImageAvailableListener(imageListener, backgroundHandler);
previewRequestBuilder.addTarget(previewReader.getSurface());
// Here, we create a CameraCaptureSession for camera preview.
cameraDevice.createCaptureSession(
Arrays.asList(surface, previewReader.getSurface()),
new CameraCaptureSession.StateCallback() {
@Override
public void onConfigured(final CameraCaptureSession cameraCaptureSession) {
// The camera is already closed
if (null == cameraDevice) {
return;
}
// When the session is ready, we start displaying the preview.
captureSession = cameraCaptureSession;
try {
// Auto focus should be continuous for camera preview.
previewRequestBuilder.set(
CaptureRequest.CONTROL_AF_MODE,
CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
// Flash is automatically enabled when necessary.
previewRequestBuilder.set(
CaptureRequest.CONTROL_AE_MODE, CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);
// Finally, we start displaying the camera preview.
previewRequest = previewRequestBuilder.build();
captureSession.setRepeatingRequest(
previewRequest, captureCallback, backgroundHandler);
} catch (final CameraAccessException e) {
LOGGER.e(e, "Exception!");
}
}
@Override
public void onConfigureFailed(final CameraCaptureSession cameraCaptureSession) {
showToast("Failed");
}
},
null);
} catch (final CameraAccessException e) {
LOGGER.e(e, "Exception!");
}
}
/**
* Configures the necessary {@link android.graphics.Matrix} transformation to `mTextureView`.
* This method should be called after the camera preview size is determined in
* setUpCameraOutputs and also the size of `mTextureView` is fixed.
*
* @param viewWidth The width of `mTextureView`
* @param viewHeight The height of `mTextureView`
*/
private void configureTransform(final int viewWidth, final int viewHeight) {
final Activity activity = getActivity();
if (null == textureView || null == previewSize || null == activity) {
return;
}
final int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
final Matrix matrix = new Matrix();
final RectF viewRect = new RectF(0, 0, viewWidth, viewHeight);
final RectF bufferRect = new RectF(0, 0, previewSize.getHeight(), previewSize.getWidth());
final float centerX = viewRect.centerX();
final float centerY = viewRect.centerY();
if (Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation) {
bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
final float scale =
Math.max(
(float) viewHeight / previewSize.getHeight(),
(float) viewWidth / previewSize.getWidth());
matrix.postScale(scale, scale, centerX, centerY);
matrix.postRotate(90 * (rotation - 2), centerX, centerY);
} else if (Surface.ROTATION_180 == rotation) {
matrix.postRotate(180, centerX, centerY);
}
textureView.setTransform(matrix);
}
/**
* Compares two {@code Size}s based on their areas.
*/
static class CompareSizesByArea implements Comparator<Size> {
@Override
public int compare(final Size lhs, final Size rhs) {
// We cast here to ensure the multiplications won't overflow
return Long.signum(
(long) lhs.getWidth() * lhs.getHeight() - (long) rhs.getWidth() * rhs.getHeight());
}
}
/**
* Shows an error message dialog.
*/
public static class ErrorDialog extends DialogFragment {
private static final String ARG_MESSAGE = "message";
public static ErrorDialog newInstance(final String message) {
final ErrorDialog dialog = new ErrorDialog();
final Bundle args = new Bundle();
args.putString(ARG_MESSAGE, message);
dialog.setArguments(args);
return dialog;
}
@Override
public Dialog onCreateDialog(final Bundle savedInstanceState) {
final Activity activity = getActivity();
return new AlertDialog.Builder(activity)
.setMessage(getArguments().getString(ARG_MESSAGE))
.setPositiveButton(
android.R.string.ok,
new DialogInterface.OnClickListener() {
@Override
public void onClick(final DialogInterface dialogInterface, final int i) {
activity.finish();
}
})
.create();
}
}
}
