Android camera2
1 like806 views
This document summarizes Takuma Lee's presentation on camera2 API experience in Android. It discusses setting up the camera, preview callbacks, face detection, common issues, and provides demo code. The presentation was given to the Taiwan Android Developer Study Group, which is a community of Android enthusiasts that meets weekly.
Android camera2
- 2. Takuma Lee@Android Study Group vmgsahm1@gmail.com Individual App Developer@?徭姙少T App Developer@蜘畜 Today¨s source code http://bit.ly/android-camera2-sample Google Repo https://github.com/googlesamples/android-Camera2Basic Licensed under the Charlie Tsai 2
- 3. Android Developer _lx ? 髄曖┌殖 Android 議?匯蛤?繁詔鹿議芙蛤 ? 芙蛤嶄械l?伏?匯 Android 祥柳肇 iOS 恷瘁撹 iOS ?垢殻議並周 ? O羨2013 / 09 ? 芙蛤?繁毅7455DevFest r 6745 ? Google Community Group ? 耽L眉ek和詔 ? 耽?埖ek?埖麼}音泯 3
- 5. 泌採孀欺x ? FB 芙蛤http://bit.ly/TADSG_FB ? Githubhttps://github.com/TADSG ? Meetuphttps://www.meetup.com/Taiwan- Android-Developer-Study-Group/ ? Telegramhttp://bit.ly/TADSG_Telegram
- 6. Agenda ? Guide ? Setting ? Preview Callback ? Face Detection ? 甚 6
- 7. Guide
- 8. Setting /**? * ID of the current {@link CameraDevice}.? */? private String mCameraId;? ? /**? * An {@link AutoFitTextureView} for camera preview.? */? private AutoFitTextureView mTextureView;? ? /**? * A {@link CameraCaptureSession } for camera preview.? */? private CameraCaptureSession mCaptureSession;? ? /**? * A reference to the opened {@link CameraDevice}.? */? private CameraDevice mCameraDevice;? ? /**? * The {@link android.util.Size} of camera preview.? */? private Size mPreviewSize;
- 9. Setting /**? * {@link CameraDevice.StateCallback} is called when {@link CameraDevice} changes its state.? */? private final CameraDevice.StateCallback mStateCallback = new CameraDevice.StateCallback() {? ? @Override? public void onOpened(@NonNull CameraDevice cameraDevice) {? // This method is called when the camera is opened. We start camera preview here.? mCameraOpenCloseLock.release();? mCameraDevice = cameraDevice;? createCameraPreviewSession();? }? ? @Override? public void onDisconnected(@NonNull CameraDevice cameraDevice) {? mCameraOpenCloseLock.release();? cameraDevice.close();? mCameraDevice = null;? }? ? @Override? public void onError(@NonNull CameraDevice cameraDevice, int error) {? mCameraOpenCloseLock.release();? cameraDevice.close();? mCameraDevice = null;? Activity activity = getActivity();? if (null != activity) {? activity.finish();? }? }? ? };
- 10. Setting /**? * An additional thread for running tasks that shouldn't block the UI.? */? private HandlerThread mBackgroundThread;? ? /**? * A {@link Handler} for running tasks in the background.? */? private Handler mBackgroundHandler;? ? /**? * An {@link ImageReader} that handles still image capture.? */? private ImageReader mImageReader;
- 11. Setting @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 (mTextureView.isAvailable()) {? openCamera(mTextureView.getWidth(), mTextureView.getHeight());? } else {? mTextureView.setSurfaceTextureListener(mSurfaceTextureListener);? }? }? ? @Override? public void onPause() {? closeCamera();? stopBackgroundThread();? super.onPause();? }
- 12. Setting /**? * A {@link CameraCaptureSession.CaptureCallback} that handles events related to JPEG capture.? */? private CameraCaptureSession.CaptureCallback mCaptureCallback? = new CameraCaptureSession.CaptureCallback() {? ? ? ? @Override? public void onCaptureProgressed(@NonNull CameraCaptureSession session,? @NonNull CaptureRequest request,? @NonNull CaptureResult partialResult) {? process(partialResult);? }? ? @Override? public void onCaptureCompleted(@NonNull CameraCaptureSession session,? @NonNull CaptureRequest request,? @NonNull TotalCaptureResult result) {? process(result);? } };
- 13. Setting private void openCamera(int width, int height) {? if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.CAMERA)? != PackageManager.PERMISSION_GRANTED) {? requestCameraPermission();? return;? }? setUpCameraOutputs(width, height);? configureTransform(width, height);? Activity activity = getActivity();? CameraManager manager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);? try {? if (!mCameraOpenCloseLock.tryAcquire(2500, TimeUnit.MILLISECONDS)) {? throw new RuntimeException("Time out waiting to lock 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);? }? }
- 14. Preview Callback /**? * Creates a new {@link CameraCaptureSession} for camera preview.? */? private void createCameraPreviewSession() {? try {? SurfaceTexture texture = mTextureView.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);? ? // We set up a CaptureRequest.Builder with the output Surface.? mPreviewRequestBuilder? = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);? mPreviewRequestBuilder.addTarget(surface); createCameraSession();? ? ? } catch (CameraAccessException e) {? e.printStackTrace();? }? }
- 15. Preview Callback // Here, we create a CameraCaptureSession for camera preview.? mCameraDevice.createCaptureSession(Arrays.asList(surface, mImageReader.getSurface()),? new CameraCaptureSession.StateCallback() {? ? @Override? public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {? // The camera is already closed? if (null == mCameraDevice) {? return;? }? ? // When the session is ready, we start displaying the preview.? mCaptureSession = cameraCaptureSession;? try {? // Auto focus should be continuous for camera preview.? mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,? CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);? // Flash is automatically enabled when necessary.? setAutoFlash(mPreviewRequestBuilder);? ? // Finally, we start displaying the camera preview.? mPreviewRequest = mPreviewRequestBuilder.build();? mCaptureSession.setRepeatingRequest(mPreviewRequest,? mCaptureCallback, mBackgroundHandler);? } catch (CameraAccessException e) {? e.printStackTrace();? }? }? ? @Override? public void onConfigureFailed(? @NonNull CameraCaptureSession cameraCaptureSession) {? showToast("Failed");? }? }, null? );
- 16. Face Detection // Here, we create a CameraCaptureSession for camera preview.? mCameraDevice.createCaptureSession(Arrays.asList(surface, mImageReader.getSurface()),? new CameraCaptureSession.StateCallback() {? ? @Override? public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {? // The camera is already closed? if (null == mCameraDevice) {? return;? }? ? // When the session is ready, we start displaying the preview.? mCaptureSession = cameraCaptureSession;? try {? // Auto focus should be continuous for camera preview.? mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,? CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);? // Face detection mode setting? mPreviewRequestBuilder.set(CaptureRequest.STATISTICS_FACE_DETECT_MODE, faceDetectMode);? // Flash is automatically enabled when necessary.? setAutoFlash(mPreviewRequestBuilder);? ? // Finally, we start displaying the camera preview.? mPreviewRequest = mPreviewRequestBuilder.build();? mCaptureSession.setRepeatingRequest(mPreviewRequest,? mCaptureCallback, mBackgroundHandler);? } catch (CameraAccessException e) {? e.printStackTrace();? }? }? ? @Override? public void onConfigureFailed(? @NonNull CameraCaptureSession cameraCaptureSession) {? showToast("Failed");? }? }, null? );
- 17. CameraDevice public static final int TEMPLATE_PREVIEW = 1; public static final int TEMPLATE_STILL_CAPTURE = 2; public static final int TEMPLATE_RECORD = 3; public static final int TEMPLATE_VIDEO_SNAPSHOT = 4; public static final int TEMPLATE_ZERO_SHUTTER_LAG = 5; public static final int TEMPLATE_MANUAL = 6;
- 18. Preview Callback // For still image captures, we use the largest available size.? Size largest = Collections.max(? Arrays.asList(map.getOutputSizes(ImageFormat.JPEG)),? new CompareSizesByArea());? mImageReader = ImageReader.newInstance(largest.getWidth(), largest.getHeight(),? ImageFormat.JPEG, /*maxImages*/2);? mImageReader.setOnImageAvailableListener(? mOnImageAvailableListener, mBackgroundHandler);
- 19. Preview Callback /**? * Creates a new {@link CameraCaptureSession} for camera preview.? */? private void createCameraPreviewSession() {? try {? SurfaceTexture texture = mTextureView.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);? ? // We set up a CaptureRequest.Builder with the output Surface.? mPreviewRequestBuilder? = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);? mPreviewRequestBuilder.addTarget(surface); createCameraSession();? ? ? } catch (CameraAccessException e) {? e.printStackTrace();? }? }
- 20. Preview Callback // Use Preview Callback? mPreviewRequestBuilder.addTarget(mImageReader.getSurface());
- 22. Face Detection
- 23. Demo
- 24. 甚
- 25. 甚 - 何y
- 26. 26
- 27. Q&A