My Android application runs image processing with opencv for android in action using JavaCameraView . It works great. Now I want to do the same image processing in the background without previewing for the user. I started with the Android service.
With this code, I can load OpenCV into a service:
import org.opencv.android.BaseLoaderCallback; import org.opencv.android.LoaderCallbackInterface; import org.opencv.android.OpenCVLoader; import android.app.Service; import android.content.Intent; import android.os.IBinder; import android.util.Log; public class CameraService extends Service { private static final String TAG = "CameraService"; BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(CameraService.this) { @Override public void onManagerConnected(int status) { switch (status) { case LoaderCallbackInterface.SUCCESS: { Log.i("", "OpenCV loaded successfully"); } break; default: { super.onManagerConnected(status); } break; } } }; @Override public int onStartCommand(Intent intent, int flags, int startId) { if(OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_4, getApplicationContext(), mLoaderCallback)) { Log.i(TAG, "Loaded OpenCV"); } else Log.i(TAG, "Couldn't load OpenCV"); return super.onStartCommand(intent, flags, startId); } @Override public IBinder onBind(Intent intent) { return null; } }
But I do not know how to capture frames, as in my previous activity onCameraFrame() ? There I implement CvCameraViewListener2 , but not in my service, because this requires a CameraBridgeViewBase , which I no longer want to show. How to process images in the background?
UPDATE → 2
I added runnable to capture frames as you told me. Downloading OpenCV and connecting to the camera work fine. But before capturing any frames, it skips frames and interrupts, because the application does too much work on the main thread.
Now here is all my camera service:
public final class MyService extends Service { private static final String TAG = MyService.class.getSimpleName(); private boolean mStopThread; private Thread mThread; private VideoCapture mCamera; private int mCameraIndex = -1; BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) { @Override public void onManagerConnected(int status) { switch (status) { case LoaderCallbackInterface.SUCCESS: { Log.i("", "OpenCV loaded successfully"); try { if (!connectCamera(640, 480)) Log.e(TAG, "Could not connect camera"); else Log.d(TAG, "Camera successfully connected"); } catch (Exception e) { Log.e(TAG, "MyServer.connectCamera throws an exception: " + e.getMessage()); } } break; default: { super.onManagerConnected(status); } break; } } }; @Override public int onStartCommand(Intent intent, int flags, int startId) { if(OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_4, getApplicationContext(), mLoaderCallback)) Log.i(TAG, "Loaded OpenCV"); else Log.i(TAG, "Couldn't load OpenCV"); return super.onStartCommand(intent, flags, startId); } public void onDestroy() { this.disconnectCamera(); Log.d(TAG, "onDestroy"); super.onDestroy(); } private boolean connectCamera(int width, int height) { if (!initializeCamera(width, height)) { Log.d(TAG, "initializeCamera failed"); return false; } else { Log.d(TAG, "initializeCamera successfully"); mThread = new Thread(new CameraWorker()); mThread.start(); return true; } } private boolean initializeCamera(int width, int height) { synchronized (this) { if (mCameraIndex == -1) mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID); else mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID + mCameraIndex); if (mCamera == null) return false; if (mCamera.isOpened() == false) return false; Size frameSize = new Size(width, height); mCamera.set(Highgui.CV_CAP_PROP_FRAME_WIDTH, frameSize.width); mCamera.set(Highgui.CV_CAP_PROP_FRAME_HEIGHT, frameSize.height); } return true; } private void releaseCamera() { synchronized (this) { if (mCamera != null) { mCamera.release(); } } } private void disconnectCamera() {
My journal:
11-29 12:28:24.370: D/OpenCVManager/Helper(5257): Init finished with status 0 11-29 12:28:24.370: D/OpenCVManager/Helper(5257): Unbind from service 11-29 12:28:24.380: D/OpenCVManager/Helper(5257): Calling using callback 11-29 12:28:24.380: I/(5257): OpenCV loaded successfully 11-29 12:28:24.380: D/OpenCV::camera(5257): CvCapture_Android::CvCapture_Android(0) 11-29 12:28:24.440: D/OpenCV_NativeCamera(5257): Connecting to CameraService v 3D 11-29 12:28:24.670: D/OpenCV_NativeCamera(5257): Instantiated new CameraHandler (0x75e4f29d, 0x71e178b8) 11-29 12:28:24.750: D/OpenCV_NativeCamera(5257): Starting preview 11-29 12:28:25.421: E/OpenCV_NativeCamera(5257): CameraHandler::doCall(void*, size_t): cameraCallback returns false (camera connection will be closed) 11-29 12:28:25.421: E/BufferQueue(5257): [unnamed-5257-0] dequeueBuffer: min undequeued buffer count (2) exceeded (dequeued=11 undequeudCount=0) 11-29 12:28:25.431: E/BufferQueue(5257): [unnamed-5257-0] dequeueBuffer: min undequeued buffer count (2) exceeded (dequeued=10 undequeudCount=1) 11-29 12:28:25.451: D/OpenCV_NativeCamera(5257): Preview started successfully 11-29 12:28:25.451: D/OpenCV_NativeCamera(5257): CameraHandler::setProperty(0, 640.000000) 11-29 12:28:25.451: D/OpenCV_NativeCamera(5257): CameraHandler::setProperty(1, 480.000000) 11-29 12:28:25.451: D/MyService(5257): initializeCamera successfully 11-29 12:28:25.451: D/MyService(5257): Camera successfully connected 11-29 12:28:25.451: I/Choreographer(5257): Skipped 86 frames! The application may be doing too much work on its main thread. 11-29 12:28:25.471: A/libc(5257): @@@ ABORTING: LIBC: HEAP MEMORY CORRUPTION IN tmalloc_small 11-29 12:28:25.471: A/libc(5257): Fatal signal 11 (SIGSEGV) at 0xdeadbaad (code=1), thread 5257 ()
What is wrong and what can I do now?