问题
I'm having a problem with my camera app. My app has:
1) a CameraActivity.class and
2) a CameraPreview.class.
CameraPreview implement a surfaceView where it's called from CameraActivity for the actual preview. (Also in CameraActivity I have the parameters)
Now the problem: When the preview is starting the preview is stretched. I tried a lot of things (so many that I cannot recall) I need someone to tell me what to write and where. Thanks in advance.
Here is the CameraActivity(Not all the code but the important I think)
private PictureCallback mPicture = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
// Replacing the button after a photho was taken.
flBtnContainer.setVisibility(View.GONE);
ibRetake.setVisibility(View.VISIBLE);
ibUse.setVisibility(View.VISIBLE);
// File name of the image that we just took.
fileName = "IMG_" + new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()).toString() + ".jpg";
// Creating the directory where to save the image. Sadly in older
// version of Android we can not get the Media catalog name
File mkDir = new File(sdRoot, dir);
mkDir.mkdirs();
// Main file where to save the data that we recive from the camera
File pictureFile = new File(sdRoot, dir + fileName);
try {
FileOutputStream purge = new FileOutputStream(pictureFile);
purge.write(data);
purge.close();
} catch (FileNotFoundException e) {
Log.d("DG_DEBUG", "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d("DG_DEBUG", "Error accessing file: " + e.getMessage());
}
// Adding Exif data for the orientation. For some strange reason the
// ExifInterface class takes a string instead of a file.
try {
exif = new ExifInterface("/sdcard/" + dir + fileName);
exif.setAttribute(ExifInterface.TAG_ORIENTATION, "" + orientation);
exif.saveAttributes();
} catch (IOException e) {
e.printStackTrace();
}
Intent intent = new Intent(CameraActivity.this, PicturePreview.class);
Bundle extras = new Bundle();
extras.putString("ImagePath", String.valueOf(pictureFile));
intent.putExtras(extras);
startActivity(intent);
//SendBroadcasts let's us instantly update the SD card with our image
sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.parse("file://"+Environment.getExternalStorageDirectory())));
}
};
private void createCamera() {
// Create an instance of Camera
mCamera = getCameraInstance();
// Setting the right parameters in the camera
Camera.Parameters params = mCamera.getParameters();
params.setRotation(90);
mCamera.setParameters(params);
// Create our Preview view and set it as the content of our activity.
mPreview = new CameraPreview(this, mCamera);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(mPreview, 0);
}
@Override
protected void onResume() {
super.onResume();
// Test if there is a camera on the device and if the SD card is
// mounted.
if (!checkCameraHardware(this)) {
Intent i = new Intent(this, NoCamera.class);
startActivity(i);
finish();
} else if (!checkSDCard()) {
Intent i = new Intent(this, NoSDCard.class);
startActivity(i);
finish();
}
// Creating the camera
createCamera();
// Register this class as a listener for the accelerometer sensor
////sensorManager.registerListener(this, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL);
}
@Override
protected void onPause() {
super.onPause();
// release the camera immediately on pause event
releaseCamera();
// removing the inserted view - so when we come back to the app we
// won't have the views on top of each other.
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.removeViewAt(0);
}
And here is the CameraPreview.class
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
boolean isPreviewRunning = true;
public CameraPreview(Context context, Camera camera) {
super(context);
mCamera = camera;
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
// deprecated setting, but required on Android versions prior to 3.0
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mHolder.setFixedSize(100, 100);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the
// preview.
try {
mCamera.setPreviewDisplay(holder);
mCamera.setDisplayOrientation(90);
mCamera.startPreview();
} catch (IOException e) {
Log.d("DG_DEBUG", "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceChanged(SurfaceHolder holder,
int format, int width, int height) {
if (isPreviewRunning){
return;
}
isPreviewRunning = true;
// 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;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e) {
// ignore: tried to stop a non-existent preview
}
// make any resize, rotate or reformatting changes here
// start preview with new settings
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e) {
Log.d("DG_DEBUG", "Error starting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
}
}
Can someone tell what am I missing? If possible I can chat in Facebook or something for faster resolve of my problem..
Update: @LikeWhiteOnRice's solution.
Here is my original code
enter image description here
Here is with LikeWhiteOnRice's code:
enter image description here
Any thoughts?
回答1:
I added the code below to my camera preview class and it works for most devices. Just so you are aware, the camera library in Android is horrible and a huge pain to work with.
Put this function in your CameraPreview class:
private Camera.Size getOptimalSize(List<Camera.Size> sizes, int h, int w) {
final double ASPECT_TOLERANCE = 0.05;
double targetRatio = (double) w/h;
if (sizes == null) {
return null;
}
Camera.Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
for (Camera.Size size : sizes) {
double ratio = (double) size.width / size.height;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Camera.Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
In your surefaceCreated function, add this before you start your preview:
Camera.Parameters cameraParameters = mCamera.getParameters();
List<Camera.Size> previewSizes = cameraParameters.getSupportedPreviewSizes();
Camera.Size optimalPreviewSize = getOptimalSize(previewSizes, getResources().getDisplayMetrics().widthPixels, getResources().getDisplayMetrics().heightPixels);
cameraParameters.setPreviewSize(optimalPreviewSize.width, optimalPreviewSize.height);
mCamera.setParameters(cameraParameters);
Edit: Also, I'm not sure if you want
mHolder.setFixedSize(100, 100);
in your constructor.
来源：https://stackoverflow.com/questions/37666337/custom-camera-preview-issue-stretch