Android - Camera preview is sideways

I am using a Preview to display what the camera see's on the screen.

I can get everything working fine, surface created, surface set and the surface is displayed.

However it always displays the picture at an incorrect 90 degree angle in portrait mode.

Such as in the picture:

alt text

I am aware that using the following code will set the picture straight:

setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);

However I have the Preview within an Activity that has other elements in it and it does not make sense for my Activity to be displayed in landscape mode. (Its disabled by default)

So I was wondering is there anyway to just change the orientation of the Preview? And leave the rest of my Activity correctly displayed in Portrait mode?

Or anyway to rotate the preview so that it is displayed correctly?

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最佳答案

This issue appeared to start out as a bug with certain hardware see here but can be overcome by using the call to mCamera.setDisplayOrientation(degrees) available in API 8. So this is how I implement it:

public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
if (isPreviewRunning) {
mCamera.stopPreview();
}


Parameters parameters = mCamera.getParameters();
Display display = ((WindowManager)getSystemService(WINDOW_SERVICE)).getDefaultDisplay();


if(display.getRotation() == Surface.ROTATION_0) {
parameters.setPreviewSize(height, width);
mCamera.setDisplayOrientation(90);
}


if(display.getRotation() == Surface.ROTATION_90) {
parameters.setPreviewSize(width, height);
}


if(display.getRotation() == Surface.ROTATION_180) {
parameters.setPreviewSize(height, width);
}


if(display.getRotation() == Surface.ROTATION_270) {
parameters.setPreviewSize(width, height);
mCamera.setDisplayOrientation(180);
}


mCamera.setParameters(parameters);
previewCamera();
}


And the previewCamera method :


public void previewCamera() {
try {
mCamera.setPreviewDisplay(mSurfaceHolder);
mCamera.startPreview();
isPreviewRunning = true;
} catch(Exception e) {
Log.d(APP_CLASS, "Cannot start preview", e);
}
}

This was on an HTC Desire and I had to initially put in logging statements in each of the rotation checks to say what the rotation was and then debugged on the device and watched the logCat output while I rotated the device. For the HTC Desire, 0 was the phone as you would have expected (portrait), 90 degrees was turning the phone 90 degrees COUNTER-CLOCKWISE (I had assumed it would have been clockwise). In the code you'll see I didn't need to do any display rotation when the phone was at 90 or 180 degrees - the device seemed to handle this itself. Only one point not working properly: The 270 degree rotation is when you turn the device 90 degrees clockwise and the display rotation counters that ok but if you rotate the device 270 degrees counter-clockwise, it doesn't appear to compensate it properly.

P.S. Note the swapover of width and height in the appropriate rotations.

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 public void surfaceCreated(SurfaceHolder holder) {
mCamera = Camera.open();
mCamera.setDisplayOrientation(90);
try {
mCamera.setPreviewDisplay(holder);
mCamera.setPreviewCallback(new PreviewCallback() {


@Override
public void onPreviewFrame(byte[] data, Camera camera) {
}
});


} catch (Exception e) {
e.printStackTrace();
}
}

try this code

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I did it taking advice of mCamera.setDisplayOrientation(90); but also rotated the bitmap because for some reason the others approaches doesnt work for me in version 2.3.3.

For rotate the bitmap i did this:

Matrix matrix = new Matrix();
matrix.postRotate(90);
imageView1 = new ImageView(this);
Bitmap bitmap = BitmapFactory.decodeFile(files[i].getAbsolutePath());
Bitmap rotatedBitmap = Bitmap.createBitmap(bitmap , 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
Bitmap scaledBitmap = Bitmap.createScaledBitmap(rotatedBitmap, 80, 80, true);
imageView1.setImageBitmap(scaledBitmap);
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try to set the display orientation. It solves my problem.

 mCamera.setDisplayOrientation(90);
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I have compared my code to the tutorial one and what finally fixed it was putting the following code into my AndroidManifext.xml: In the <activity> tag:

android:screenOrientation="landscape"
android:configChanges="keyboardHidden|orientation">
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I was having a problem with front Camera(Upside down issue). Then I used the following method documented in Android Docs -

public void setCameraDisplayOrientation(Activity activity , int icameraId , Camera camera1s)
{
CameraInfo cameraInfo = new CameraInfo();


Camera.getCameraInfo(icameraId, cameraInfo);


int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();


int degrees = 0; // k


switch (rotation)
{
case Surface.ROTATION_0:
degrees = 0;
break;
case Surface.ROTATION_90:
degrees = 90;
break;
case Surface.ROTATION_180:
degrees = 180;
break;
case Surface.ROTATION_270:
degrees = 270;
break;


}


int result;


if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT)
{
// cameraType=CAMERATYPE.FRONT;


result = (cameraInfo.orientation + degrees) % 360;
result = (360 - result) % 360; // compensate the mirror


}
else
{ // back-facing


result = (cameraInfo.orientation - degrees + 360) % 360;


}
// displayRotate=result;
camera.setDisplayOrientation(result);




}
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public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// If your preview can change or rotate, take care of those events here.
// Make sure to stop the preview before resizing or reformatting it.


if (mHolder.getSurface() == null) {
// preview surface does not exist
return;
}


try {
mCamera.stopPreview();
} catch (Exception e) {
e.printStackTrace();
}


Camera.Parameters parameters = mCamera.getParameters();
Display display = ((WindowManager) getContext().getSystemService(WINDOW_SERVICE)).getDefaultDisplay();


if (display.getRotation() == Surface.ROTATION_0) {
parameters.setPreviewSize(h, w);
mCamera.setDisplayOrientation(90);
}


if (display.getRotation() == Surface.ROTATION_90) {
parameters.setPreviewSize(w, h);
mCamera.setDisplayOrientation(0);
}


if (display.getRotation() == Surface.ROTATION_180) {
parameters.setPreviewSize(h, w);
mCamera.setDisplayOrientation(270);
}


if (display.getRotation() == Surface.ROTATION_270) {
parameters.setPreviewSize(w, h);
mCamera.setDisplayOrientation(180);
}


previewCamera();
}


public void previewCamera() {
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
//Log.d(APP_CLASS, "Cannot start preview", e);
e.printStackTrace();
}
}
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I think the SENSOR_ORIENTATION value will explain what value to be used for the rotation instead of hardcoding to 90 degrees

CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
if (manager == null) {
Log.i(TAG, "camera manager is null");
return;
}
for (String id: manager.getCameraIdList()) {
CameraCharacteristics characteristics = manager.getCameraCharacteristics(id);
Integer orientation = characteristics.get(CameraCharacteristics.SENSOR_ORIENTATION);
Log.i(TAG, "camera sensor orientation is " + orientation);
}

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