I took the Google example for using ImageReader
from here.
The code uses Camera2
API and ImageReader
to such that querying image runs in different thread than previewing it.
As I want to target Android KitKat (API 20), I need to modify the code to use older Camera API with keeping the ImageReader
part as is.
Here is the part of original code that sets onImageAvailableListener
:
/**
* THIS IS CALLED WHEN OPENING CAMERA
* Sets up member variables related to camera.
*
* @param width The width of available size for camera preview
* @param height The height of available size for camera preview
*/
private void setUpCameraOutputs(int width, int height) {
Activity activity = getActivity();
CameraManager manager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);
try {
for (String cameraId : manager.getCameraIdList()) {
CameraCharacteristics characteristics
= manager.getCameraCharacteristics(cameraId);
// We don't use a front facing camera in this sample.
Integer facing = characteristics.get(CameraCharacteristics.LENS_FACING);
if (facing != null && facing == CameraCharacteristics.LENS_FACING_FRONT) {
continue;
}
StreamConfigurationMap map = characteristics.get(
CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
if (map == null) {
continue;
}
// 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);
.
.
.
.
}
Now I was able to use older Camera API. But I am lost in connecting it with ImageReader
. So I don't know how should I set onImageListener
so that I can access it once the image is delivered.
Here is my modification :
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mTextureView = (AutoFitTextureView) v.findViewById(R.id.texture);
mTextureView.setSurfaceTextureListener(new SurfaceTextureListener() {
@Override
public void onSurfaceTextureUpdated(SurfaceTexture surface) {
}
@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture surface,
int width, int height) {
}
@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
return true;
}
@Override
public void onSurfaceTextureAvailable(SurfaceTexture surface,
int width, int height) {
mCamera = Camera.open();
try {
Camera.Parameters parameters = mCamera.getParameters();
if (getActivity().getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE) {
// parameters.set("orientation", "portrait"); // For
// Android Version 2.2 and above
mCamera.setDisplayOrientation(90);
// For Android Version 2.0 and above
parameters.setRotation(90);
}
mCamera.setParameters(parameters);
mCamera.setPreviewTexture(surface);
} catch (IOException exception) {
mCamera.release();
}
mCamera.startPreview();
setUpCameraOutputs(width, height);
tfPreviewListener.initialize(getActivity().getAssets(), scoreView);
}
});
}
My question is how should I add ImageReader
in the code above to make it work properly?
Thanks in advance.