我的应用程序使用camera2 API管理设备摄像头的预览。但问题是,我的设备是一个Nexus5x,有翻转传感器和众所周知的反向景观“问题”。我在某个地方读到,camera2 api“自动”处理这个问题,但我认为只有在设置捕获会话时针对surface对象的表面,这才是正确的。但是相反,我的目标是建立在表面纹理之上的表面,我进一步使用它来渲染预览以获得立体视图,并且随着这种方法问题的持续存在,我得到了颠倒的框架。下面是代码,这几乎是使用camera2 API时的常规工作流。
private void openCamera() {
CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
Log.e(TAG, "is camera open");
try {
cameraId = manager.getCameraIdList()[CAMERA_SOURCE];
CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);
StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
assert map != null;
imageDimension = map.getOutputSizes(SurfaceTexture.class)[CAMERA_SOURCE];
// Add permission for camera and let user grant the permission
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(MainActivity.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();
}
Log.e(TAG, "openCamera X");
}
private final CameraDevice.StateCallback stateCallback = new CameraDevice.StateCallback() {
@Override
public void onOpened(CameraDevice camera) {
//This is called when the camera is open
Log.e(TAG, "onOpened");
cameraDevice = camera;
createCameraPreview();
}
@Override
public void onDisconnected(CameraDevice camera) {
cameraDevice.close();
}
@Override
public void onError(CameraDevice camera, int error) {
cameraDevice.close();
cameraDevice = null;
}
};
protected void createCameraPreview() {
try {
// Create ImageReader Surface
int max = 2;
mReader = ImageReader.newInstance(mWidth, mHeight, ImageFormat.YUV_420_888, max);
ImageReader.OnImageAvailableListener readerListener = new ImageReader.OnImageAvailableListener() {
@Override
public void onImageAvailable(ImageReader mReader) {
Image image = null;
image = mReader.acquireLatestImage();
if (image == null) {
return;
}
byte[] bytes = convertYUV420ToNV21(image);
nativeVideoFrame(bytes);
image.close();
}
};
mReader.setOnImageAvailableListener(readerListener, mBackgroundHandler);
// Create Texture Surface
texture = createTexture();
mSurfaceTexture = new SurfaceTexture(texture);
mSurfaceTexture.setOnFrameAvailableListener(this);
mSurfaceTexture.setDefaultBufferSize(imageDimension.getWidth(), imageDimension.getHeight());
mSurface = new Surface(mSurfaceTexture);
//Attach surfaces to CaptureRequest
List<Surface> outputSurfaces = new ArrayList<Surface>(2);
outputSurfaces.add(mReader.getSurface());
outputSurfaces.add(mSurface);
captureRequestBuilder = cameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
captureRequestBuilder.addTarget(mSurface);
captureRequestBuilder.addTarget(mReader.getSurface());
//Define the capture request
cameraDevice.createCaptureSession(outputSurfaces, new CameraCaptureSession.StateCallback(){
@Override
public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
//The camera is already closed
if (null == cameraDevice) {
return;
}
// When the session is ready, we start displaying the preview.
cameraCaptureSessions = cameraCaptureSession;
updatePreview();
}
@Override
public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
Toast.makeText(MainActivity.this, "Configuration change", Toast.LENGTH_SHORT).show();
}
}, null);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
protected void updatePreview() {
if(null == cameraDevice) {
Log.e(TAG, "updatePreview error, return");
}
captureRequestBuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);
try {
cameraCaptureSessions.setRepeatingRequest(captureRequestBuilder.build(), null, mBackgroundHandler);
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
我的问题是:我该怎么做才能自己解决逆向景观问题?哪一行代码,我应该在哪里添加?
谢谢,
JM
发布于 2017-12-15 07:05:41
由于您使用的是SurfaceTexture和ImageReader,所以您必须自己处理轮调。Camera2 API与SurfaceView或TextureView一起使用时会自动处理旋转。
这就是说,一旦您通过ImageReader.OnImageAvailableListener回调获得帧的字节,就可以手动旋转它们,或者更好的是直接在GPU上执行对OpenGL纹理的操作。
请注意,旋转180°等效于垂直翻转一次,水平翻转一次,在OpenGL上,这意味着可以:
https://stackoverflow.com/questions/39126356
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