I've implemented a service to take a picture from a background thread, but the photo never gets taken on any of my devices... here is the code (logging output below):
public class PhotoCaptureService extends Service {
private static final String TAG = "PhotoCaptureService";
#Override
public void onStart(Intent intent, int startId) {
super.onStart(intent, startId);
Log.d(TAG, "Starting the PhotoCaptureService");
takePhoto();
}
private void takePhoto() {
Log.d(TAG, "Preparing to take photo");
Camera camera = null;
try {
camera = Camera.open();
} catch (RuntimeException e) {
Log.e(TAG, "Camera not available", e);
return;
}
if (null == camera) {
Log.e(TAG, "Could not get camera instance");
return;
}
Log.d(TAG, "Got the camera, creating the dummy surface texture");
SurfaceTexture dummySurfaceTexture = new SurfaceTexture(0);
try {
camera.setPreviewTexture(dummySurfaceTexture);
} catch (Exception e) {
Log.e(TAG, "Could not set the surface preview texture", e);
}
Log.d(TAG, "Preview texture set, starting preview");
camera.startPreview();
Log.d(TAG, "Preview started");
camera.takePicture(null, null, new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
Log.d(TAG, "Photo taken, stopping preview");
camera.stopPreview();
Log.d(TAG, "Preview stopped, releasing camera");
camera.release();
Log.d(TAG, "Camera released");
}
});
}
Logging output:
D/PhotoCaptureService﹕ Starting the PhotoCaptureService
D/PhotoCaptureService﹕ Preparing to take photo
D/PhotoCaptureService﹕ Got the camera, creating the dummy surface texture
D/PhotoCaptureService﹕ Preview texture set, starting preview
D/PhotoCaptureService﹕ Preview started
At this point nothing else happens, the onPictureTaken method never gets called and there is no error or exception thrown. Does anyone know why this is happening? I've looked at every camera tutorial on StackOverflow and nothing seems to work.
From my experience and what I've read, the dummy SurfaceTexture strategy doesn't work on all phones. Try instead adding a 1x1 pixel SurfaceView and starting the preview in the SurfaceView.getHolder()'s onSurfaceCreated callback (added via addCallback).
See Taking picture from camera without preview for more information.
Related
I am using custom surface view to capture the image in android. After clicking the image I need to preview the captured image with Retake, Use Photo button options. Until this everything is working fine.
When I lock and unlock my screen this captured image preview is reset by the live camera since camera.startPreview() is called in the onResume. If this method call is removed from onResume, then only black screen is visible.
This is my code on onResume
#Override
protected void onResume() {
super.onResume();
if (camera == null) {
initializeCamera();
} else {
try {
camera.startPreview();
} catch (Exception e) {
Log.e(TAG, e.getMessage(), e);
}
}
sensorManager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_NORMAL);
sensorManager.registerListener(this, magneticField, SensorManager.SENSOR_DELAY_NORMAL);
}
This is surfaceCreated method
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
camera.setPreviewDisplay(surfaceView.getHolder());
} catch (Exception e) {
Log.e(TAG, e.getMessage(), e);
}
}
Is there a way to preserve the last captured image in surface onresume?
I use this to preserve the image captured on screen
//you can omit this as in onresume() you re initialise your camera if null
yourCameraSurfaceView.yourCamera=null;
//remove Callback from holder when you capture the image
yourCameraSurfaceView.yourHolder.removeCallback(yourCameraSurfaceView);
I have used zbar scanner for android and it captures the barcodes quite easily.
But the problem is that on phones which have autofocus, it captures the barcodes too quickly to detect it correctly.
If only it could wait for a few milliseconds more, it could then be able to capture more clearer image and thereby not show "not found" page.
How can I solve this problem?
Is there a provision to delay the focus on the barcode?
Maybe a delay in capturing the image?
Are you talking about the example code, CameraTestActivity.java?
Implement a counter that counts for similar scanning results. If the scanning result remains the same (e.g. for 10 times in a row), we can assume the result is quite reliable.
I really like #Juuso_Ohtonen's reply, and actually just used it in my own reader, however if you want an AutoFocus delay you can create a Camera.AutoFocusCallback object and implement its onAutoFocus method with a .postDelayed. This object is then used on your Camera camera.autoFocus() method.
// Mimic continuous auto-focusing
Camera.AutoFocusCallback autoFocusCB = new Camera.AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
autoFocusHandler.postDelayed(doAutoFocus, 1000);
}
};
This section is used in the class that extends SurfaceView, which then implements surfaceChanged();
public CameraPreview(Context context, Camera camera,
PreviewCallback previewCb,
AutoFocusCallback autoFocusCb) {
super(context);
mCamera = camera;
previewCallback = previewCb;
autoFocusCallback = autoFocusCb;
// 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);
}
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
/*
* 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
}
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.setPreviewCallback(previewCallback);
mCamera.startPreview();
mCamera.autoFocus(autoFocusCallback);
} catch (Exception e) {
Log.d("DBG", "Error starting camera preview: " + e.getMessage());
}
}
I've searched all over on the web and I can't find out what that 1001 error is. A few seconds after that I get the camera 100 error but I can't find out what the first error is. Does anyone have any ideas?
I encountered this error as well on my S3. I believe I tracked it down to how the camera preview surface was used by the MediaRecorder. In my case the preview display was getting reset when I was attempting to start recording. I solved it by cleaning out my code and just used the calls to set, start and stop the preview display in the SurfaceView implementation below (from the Android Camera developer guide):
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
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);
}
public void surfaceCreated(SurfaceHolder holder) {
// The Surface has been created, now tell the camera where to draw the preview.
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.d(TAG, "Error setting camera preview: " + e.getMessage());
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// empty. Take care of releasing the Camera preview in your activity.
}
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;
}
// stop preview before making changes
try {
mCamera.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
// set preview size and make any resize, rotate or
// reformatting changes here
// start preview with new settings
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e){
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
}
Just thought I would add a post here for future reference. This issue bothered me for a long time.
It turns out that my problem was caused by an incorrect preview size, although the resolution set was obtained from the getSupportedPictureSize method.
So for example you can get the sizes as follows:
//first entry in list is 1392x1392 for front facing camera on an S3
List<Camera.Size> supportedPictureSizes = params.getSupportedPictureSizes();
Setting this resolution or neglecting to set a picture size alltogether will cause the dreaded error 1001.
If you encounter this on any other device I would recommend trying different picture sizes.
So there was another reason for why I got it on my Galaxy S3. I was using a TextureView to show my camera preview and got this dreaded error when pressing the home button after a successful preview and then entering the app again. In the onResume() function I started up the preview again and found that I had not released the SurfaceTexture instance variable in the onSurfaceTextureDestroyed() function.
I added the release line to this function and it now looks like this and works perfectly:
#Override public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
mSurfaceTexture = null; //This was the offending culprit.
releaseMediaPlayer();
releaseVideoRecorder();
releaseCamera();
return false;
}
In my case, in Samsung S3, the video-size parameter was not set and this led to the 1001 error. Setting the video size on the media recorder using preview size fixed the issue. However, this change may fail on other devices since the parameter may or may not be available/set in all devices. The following code addresses most of the devices:
if(params.get("video-size") != null && params.get("video-size").isEmpty()) {
int videoWidth = params.getPreviewSize().width;
int videoHeight = params.getPreviewSize().height;
mediaRecorder.setVideoSize(videoWidth, videoHeight);
} else {
mediaRecorder.setVideoSize(profile.videoFrameWidth, profile.videoFrameHeight);
}
I have classic android app with camera preview (common implem that can be found in many tutorials [marakana etc.]) that is supposed to take picture in a given time interval. Threading and killing threads is done, errors such "method called after release" are handled. But sometimes the well-known error 100 occurs. I accepted the fact that it happens and tried to handle it too. I implemented ErrorCallback and its onError method where the current camera object is released and instantiated a new one as written in official documentation.
But (with no surprise) it is not enough. New camera is maybe wrongly allocated because an message "CameraDemo has been exited unexpectedly" appears now.
I've read many docs and examples in hope, that a proper proceeding will be somewhere explained but no one has such problem apparently. So I would like to ask what else should I do beside releasing and creating new camera? Here is the code:
ErrorCallback CEC = new ErrorCallback()
{
public void onError(int error, Camera camera)
{
Log.d("CameraDemo", "camera error detected");
if(error == Camera.CAMERA_ERROR_SERVER_DIED)
{
Log.d("CameraDemo", "attempting to reinstantiate new camera");
camera.stopPreview();
camera.setPreviewCallback(null);
camera.release(); //written in documentation...
camera = null;
camera = Camera.open();
}
}
};
Shortly - if I release and recreate camera in onError callback then RuntimeException Method called after release (takePicture) is raised. So should I somehow assign the surface holder to camera again or recreate the surface holder too?
It would be enough to direct me e.g. to some forums, where it is described or solved, etc. Thanks for any help.
In my app to handle the camere i use this :
public void onResume() {
super.onResume();
if(mCamera == null)
mCamera = getCameraInstance():
}
public static Camera getCameraInstance() {
mCamera = null;
try {
mCamera = Camera.open();
Parameters parameters = mCamera.getParameters();
mCamera.cancelAutoFocus();
mCamera.setPreviewCallback(yourPreviewCb);
mCamera.startPreview();
mCamera.setParameters(parameters);
mCamera.autoFocus(yourAutoFocusCB);
} catch (Exception e) {
//TODO
}
return mCamera;
}
The mCamera = null in the getCameraInstance() is just to be sure there is no camera running at all.
I think you need to recreate a complete camera, not just open it with the
camera.open();
Set this in the onResume or in the error callback, depending on your needs.
This is how I fixed it, here is a sample of code, think you get the idea:
private Camera camera;
// code...
public Camera getCameraInstance() {
Camera camera = Camera.open();
// code...
camera.setErrorCallback(new ErrorCallback() {
#Override
public void onError(int error, Camera camera) {
if(error == Camera.CAMERA_ERROR_SERVER_DIED) {
releaseCamera();
startCamera();
}
}
});
return camera;
}
protected void startCamera() {
if(getCamera() == null)
setCamera(getCameraInstance());
refreshCamera();
}
protected void releaseCamera() {
if (getCamera() != null) {
getCamera().release();
setCamera(null);
}
}
public Camera getCamera() {
return camera;
}
public void setCamera(Camera camera) {
this.camera = camera;
}
when using the Camera.PreviewCallback implementation the onPreviewFrame is called without problem after initializing camera and starting preview (Camera.startPrevew()). The problem is if I make a video recording using MediaRecorder onPreviewFrame does not get called any more.
I understand that when using MediaRecorder to record video stops the Camera.PreviewCallback, but why can't it be restarted?
I have tried resetting the camera preview callback (setPreviewCallback(callback)) and restarting startPreview, but while I have a preview there is no call to onPreviewFrame.
You must call setPreviewCallback in the surfaceChanged method, not only in the surfaceCreated.
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
if (mHolder.getSurface() == null){
return;
}
try {
mCamera.stopPreview();
} catch (Exception e){
// ignore: tried to stop a non-existent preview
}
try {
mCamera.setPreviewCallback(this);
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (Exception e){
Log.d(TAG, "Error starting camera preview: " + e.getMessage());
}
}
I had a similar problem; see
setOneShotPreviewCallback not hitting onPreviewFrame() in callback
What I discovered was that after calling Camera#unlock() to prepare the MediaRecorder, it was necessary to call Camera#reconnect() before setting the preview callback. This is because Camera.unlock() detaches the camera from the process to let the MediaRecorder connect to it.
http://developer.android.com/reference/android/hardware/Camera.html#unlock()
In my investigations I also discovered that if you set any preview callbacks using other methods than the one shot method, you have to reset all of these after calling Camera#reconnect() as well. So, briefly:
mCamera.unlock();
//set up MediaRecorder
mCamera.reconnect();
mCamera.setPreviewCallback(mCallback);
//or whatever callback method you want to use
//and even if you've set this callback already
I hope that helps!
You should call it within new instantiation of previewCallBacks() interface, like below
public void surfaceCreated(SurfaceHolder holder) {
// if (mediaRecorder == null) {
try {
camera = Camera.open();
camera.setPreviewCallback(new PreviewCallback() {
public void onPreviewFrame(byte[] _data, Camera _camera) {
}
}
}
}
You need to call startPreview() again after a video or photo was taken.