adding initial version of a sample with new Camera-View handling design

samples/android/CMakeLists.txt

@@ -17,6 +17,8 @@ add_subdirectory(tutorial-2-opencvcamera)
 add_subdirectory(tutorial-3-native)
 add_subdirectory(tutorial-4-mixed)
 
+add_subdirectory(camera-preview)
+
 #hello-android sample
 if(HAVE_opencv_highgui)
   ocv_include_modules_recurse(opencv_highgui opencv_core)

samples/android/camera-preview/.classpath

+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="src" path="gen"/>
+	<classpathentry kind="con" path="com.android.ide.eclipse.adt.ANDROID_FRAMEWORK"/>
+	<classpathentry kind="con" path="com.android.ide.eclipse.adt.LIBRARIES"/>
+	<classpathentry kind="output" path="bin/classes"/>
+</classpath>

samples/android/camera-preview/.project

+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>CameraWriter</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>com.android.ide.eclipse.adt.ResourceManagerBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>com.android.ide.eclipse.adt.PreCompilerBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>com.android.ide.eclipse.adt.ApkBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>com.android.ide.eclipse.adt.AndroidNature</nature>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

samples/android/camera-preview/.settings/org.eclipse.jdt.core.prefs

+#Wed Jun 29 04:36:40 MSD 2011
+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.5
+org.eclipse.jdt.core.compiler.compliance=1.5
+org.eclipse.jdt.core.compiler.source=1.5

samples/android/camera-preview/AndroidManifest.xml

+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.opencv.test.camerawriter"
+    android:versionCode="1"
+    android:versionName="1.0" >
+
+    <uses-permission android:name="android.permission.CAMERA"/>
+    <uses-feature android:name="android.hardware.camera" />
+    <uses-feature android:name="android.hardware.camera.autofocus" />
+
+    <uses-sdk android:minSdkVersion="8" />
+
+    <application
+        android:icon="@drawable/ic_launcher"
+        android:label="@string/app_name"
+        android:theme="@style/AppTheme" >
+        <activity
+            android:name=".CameraWriterActivity"
+            android:label="@string/title_activity_camera_writer" >
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>
\ No newline at end of file

samples/android/camera-preview/CMakeLists.txt

+set(sample example-camera-preview)
+
+add_android_project(${sample} "${CMAKE_CURRENT_SOURCE_DIR}" LIBRARY_DEPS ${OpenCV_BINARY_DIR} SDK_TARGET 11 ${ANDROID_SDK_TARGET})
+if(TARGET ${sample})
+  add_dependencies(opencv_android_examples ${sample})
+endif()

samples/android/camera-preview/res/layout/activity_camera_writer.xml

+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent" >
+
+	<view class="org.opencv.test.camerawriter.OpenCvNativeCameraView"
+	android:id="@+id/camera_surface_view"
+	android:layout_width = "fill_parent"
+	android:layout_height="fill_parent"
+    />
+
+
+</RelativeLayout>

samples/android/camera-preview/res/menu/activity_camera_writer.xml

+<menu xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:id="@+id/menu_settings"
+        android:title="@string/menu_settings"
+        android:orderInCategory="100"
+        android:showAsAction="never" />
+</menu>

samples/android/camera-preview/res/values-v11/styles.xml

+<resources>
+
+    <style name="AppTheme" parent="android:Theme.Holo.Light" />
+
+</resources>
\ No newline at end of file

samples/android/camera-preview/res/values/strings.xml

+<resources>
+
+    <string name="app_name">CameraWriter</string>
+    <string name="menu_settings">Settings</string>
+    <string name="title_activity_camera_writer">CameraWriterActivity</string>
+
+</resources>
\ No newline at end of file

samples/android/camera-preview/res/values/styles.xml

+<resources>
+
+    <style name="AppTheme" parent="android:Theme.Light" />
+
+</resources>
\ No newline at end of file

samples/android/camera-preview/src/org/opencv/test/camerawriter/CameraWriterActivity.java

+package org.opencv.test.camerawriter;
+
+import org.opencv.android.BaseLoaderCallback;
+import org.opencv.android.LoaderCallbackInterface;
+import org.opencv.android.OpenCVLoader;
+import org.opencv.core.Mat;
+import org.opencv.test.camerawriter.OpenCvCameraBridgeViewBase.CvCameraViewListener;
+
+import android.os.Bundle;
+import android.app.Activity;
+import android.util.Log;
+import android.view.Menu;
+
+public class CameraWriterActivity extends Activity implements CvCameraViewListener {
+
+    protected static final String TAG = "CameraWriterActivity";
+
+
+        private OpenCvCameraBridgeViewBase mCameraView;
+
+
+    private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
+	@Override
+	public void onManagerConnected(int status) {
+	   switch (status) {
+	       case LoaderCallbackInterface.SUCCESS:
+		      Log.i(TAG, "OpenCV loaded successfully");
+		      // Create and set View
+		      mCameraView.setMaxFrameSize(640, 480);
+		      mCameraView.enableView();
+		      break;
+	       default:
+	      super.onManagerConnected(status);
+		break;
+	   }
+	}
+    };
+
+        @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_camera_writer);
+
+        mCameraView = (OpenCvCameraBridgeViewBase)findViewById(R.id.camera_surface_view);
+        mCameraView.setCvCameraViewListener(this);
+        OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mLoaderCallback);
+
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        getMenuInflater().inflate(R.menu.activity_camera_writer, menu);
+        return true;
+    }
+
+        @Override
+        public void onCameraViewStarted(int width, int height) {
+                // TODO Auto-generated method stub
+
+        }
+
+        @Override
+        public void onCameraViewStopped() {
+                // TODO Auto-generated method stub
+
+        }
+
+        @Override
+        public Mat onCameraFrame(Mat inputFrame) {
+                return inputFrame;
+        }
+}

samples/android/camera-preview/src/org/opencv/test/camerawriter/OpenCvCameraBridgeViewBase.java

+package org.opencv.test.camerawriter;
+
+import java.util.List;
+
+import org.opencv.android.Utils;
+import org.opencv.core.Mat;
+import org.opencv.core.Size;
+import org.opencv.highgui.Highgui;
+import org.opencv.highgui.VideoCapture;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.view.SurfaceHolder;
+import android.view.SurfaceView;
+
+/**
+ * This is a basic class, implementing the interaction with Camera and OpenCV library.
+ * The main responsibility of it - is to control when camera can be enabled, process the frame,
+ * call external listener to make any adjustments to the frame and then draw the resulting
+ * frame to the screen.
+ * The clients shall implement CvCameraViewListener
+ */
+public abstract class OpenCvCameraBridgeViewBase extends SurfaceView implements SurfaceHolder.Callback {
+
+        private static final int MAX_UNSPECIFIED = -1;
+
+        protected int mFrameWidth;
+        protected int mFrameHeight;
+
+        protected int mMaxHeight;
+        protected int mMaxWidth;
+
+        private Bitmap mCacheBitmap;
+
+
+        public OpenCvCameraBridgeViewBase(Context context, AttributeSet attrs) {
+                super(context,attrs);
+                getHolder().addCallback(this);
+                mMaxWidth = MAX_UNSPECIFIED;
+                mMaxHeight = MAX_UNSPECIFIED;
+
+        }
+
+        public interface CvCameraViewListener {
+                /**
+                 * This method is invoked when camera preview has started. After this method is invoked
+                 * the frames will start to be delivered to client via the onCameraFrame() callback.
+                 * @param width -  the width of the frames that will be delivered
+                 * @param height - the height of the frames that will be delivered
+                 */
+                public void onCameraViewStarted(int width, int height);
+
+                /**
+                 * This method is invoked when camera preview has been stopped for some reason.
+                 * No frames will be delivered via onCameraFrame() callback after this method is called.
+                 */
+                public void onCameraViewStopped();
+
+                /**
+                 * This method is invoked when delivery of the frame needs to be done.
+                 * The returned values - is a modified frame which needs to be displayed on the screen.
+                 */
+                public Mat onCameraFrame(Mat inputFrame);
+
+        }
+
+
+        private static final int STOPPED = 0;
+        private static final int STARTED = 1;
+        private  static final String TAG = "SampleCvBase";
+
+        private CvCameraViewListener mListener;
+        private int mState = STOPPED;
+
+        private boolean mEnabled;
+        private boolean mSurfaceExist;
+
+
+
+        private Object mSyncObject = new Object();
+
+        public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
+                synchronized(mSyncObject) {
+                        if (!mSurfaceExist) {
+                                mSurfaceExist = true;
+                                checkCurrentState();
+                        } else {
+                                /** Surface changed. We need to stop camera and restart with new parameters */
+                                /* Pretend that old surface has been destroyed */
+                                mSurfaceExist = false;
+                                checkCurrentState();
+                                /* Now use new surface. Say we have it now */
+                                mSurfaceExist = true;
+                                checkCurrentState();
+                        }
+                }
+        }
+
+        public void surfaceCreated(SurfaceHolder holder) {
+                /* Do nothing. Wait until surfaceChanged delivered */
+        }
+
+        public void surfaceDestroyed(SurfaceHolder holder) {
+                synchronized(mSyncObject) {
+                        mSurfaceExist = false;
+                        checkCurrentState();
+                }
+        }
+
+
+        /**
+         * This method is provided for clients, so they can enable the camera connection.
+         * The actuall onCameraViewStarted callback will be delivered only after both this method is called and surface is available
+         */
+        public void enableView() {
+                synchronized(mSyncObject) {
+                        mEnabled = true;
+                        checkCurrentState();
+                }
+        }
+
+        /**
+         * This method is provided for clients, so they can disable camera connection and stop
+         * the delivery of frames eventhough the surfaceview itself is not destroyed and still stays on the scren
+         */
+        public void disableView() {
+                synchronized(mSyncObject) {
+                        mEnabled = false;
+                        checkCurrentState();
+                }
+        }
+
+
+        public void setCvCameraViewListener(CvCameraViewListener listener) {
+                mListener = listener;
+        }
+
+        /**
+         * This method sets the maximum size that camera frame is allowed to be. When selecting
+         * size - the biggest size which less or equal the size set will be selected.
+         * As an example - we set setMaxFrameSize(200,200) and we have 176x152 and 320x240 sizes. The
+         * preview frame will be selected with 176x152 size.
+         * This method is usefull when need to restrict the size of preview frame for some reason (for example for video recording)
+         * @param maxWidth - the maximum width allowed for camera frame.
+         * @param maxHeight - the maxumum height allowed for camera frame
+         */
+        public void setMaxFrameSize(int maxWidth, int maxHeight) {
+                mMaxWidth = maxWidth;
+                mMaxHeight = maxHeight;
+        }
+
+        /**
+         * Called when mSyncObject lock is held
+         */
+        private void checkCurrentState() {
+                int targetState;
+
+                if (mEnabled && mSurfaceExist) {
+                        targetState = STARTED;
+                } else {
+                        targetState = STOPPED;
+                }
+
+                if (targetState != mState) {
+                        /* The state change detected. Need to exit the current state and enter target state */
+                        processExitState(mState);
+                        mState = targetState;
+                        processEnterState(mState);
+                }
+        }
+
+        private void processEnterState(int state) {
+                switch(state) {
+                case STARTED:
+                        onEnterStartedState();
+                        if (mListener != null) {
+                                mListener.onCameraViewStarted(mFrameWidth, mFrameHeight);
+                        }
+                        break;
+                case STOPPED:
+                        onEnterStoppedState();
+                        if (mListener != null) {
+                                mListener.onCameraViewStopped();
+                        }
+                        break;
+                };
+        }
+
+
+        private void processExitState(int state) {
+                switch(state) {
+                case STARTED:
+                        onExitStartedState();
+                        break;
+                case STOPPED:
+                        onExitStoppedState();
+                        break;
+                };
+        }
+
+        private void onEnterStoppedState() {
+                /* nothing to do */
+        }
+
+        private void onExitStoppedState() {
+                /* nothing to do */
+        }
+
+        private void onEnterStartedState() {
+
+                connectCamera(getWidth(), getHeight());
+                /* Now create cahe Bitmap */
+                mCacheBitmap = Bitmap.createBitmap(mFrameWidth, mFrameHeight, Bitmap.Config.ARGB_8888);
+
+        }
+
+        private void onExitStartedState() {
+
+                disconnectCamera();
+                if (mCacheBitmap != null) {
+                        mCacheBitmap.recycle();
+                }
+        }
+
+
+        /**
+         * This method shall be called by the subclasses when they have valid
+         * object and want it to be delivered to external client (via callback) and
+         * then displayed on the screen.
+         * @param frame - the current frame to be delivered
+         */
+        protected void deliverAndDrawFrame(Mat frame) {
+                Mat modified;
+
+                synchronized(mSyncObject) {
+                if (mListener != null) {
+			modified = mListener.onCameraFrame(frame);
+                } else {
+			modified = frame;
+                }
+
+                if (modified != null) {
+                    Utils.matToBitmap(modified, mCacheBitmap);
+                }
+
+                if (mCacheBitmap != null) {
+                    Canvas canvas = getHolder().lockCanvas();
+                    if (canvas != null) {
+                        canvas.drawBitmap(mCacheBitmap, (canvas.getWidth() - mCacheBitmap.getWidth()) / 2, (canvas.getHeight() - mCacheBitmap.getHeight()) / 2, null);
+                        getHolder().unlockCanvasAndPost(canvas);
+                    }
+                }
+                }
+        }
+
+        /**
+         * This method is invoked shall perform concrete operation to initialize the camera.
+         * CONTRACT: as a result of this method variables mFrameWidth and mFrameHeight MUST be
+         * initialized with the size of the Camera frames that will be delivered to external processor.
+         * @param width - the width of this SurfaceView
+         * @param height - the height of this SurfaceView
+         */
+        protected abstract void connectCamera(int width, int height);
+
+        /**
+         * Disconnects and release the particular camera object beeing connected to this surface view.
+         * Called when syncObject lock is held
+         */
+        protected abstract void disconnectCamera();
+
+
+        /**
+         * This helper method can be called by subclasses to select camera preview size.
+         * It goes over the list of the supported preview sizes and selects the maximum one which
+         * fits both values set via setMaxFrameSize() and surface frame allocated for this view
+         * @param supportedSizes
+         * @param surfaceWidth
+         * @param surfaceHeight
+         * @return
+         */
+        protected Size calculateCameraFrameSize(List<Size> supportedSizes, int surfaceWidth, int surfaceHeight) {
+                int calcWidth = 0;
+                int calcHeight = 0;
+
+                int maxAllowedWidth = (mMaxWidth != MAX_UNSPECIFIED && mMaxWidth < surfaceWidth)? mMaxWidth : surfaceWidth;
+                int maxAllowedHeight = (mMaxHeight != MAX_UNSPECIFIED && mMaxHeight < surfaceHeight)? mMaxHeight : surfaceHeight;
+
+        for (Size size : supportedSizes) {
+            if (size.width <= maxAllowedWidth && size.height <= maxAllowedHeight) {
+		if (size.width >= calcWidth && size.height >= calcHeight) {
+                        calcWidth = (int) size.width;
+                        calcHeight = (int) size.height;
+		}
+            }
+        }
+                return new Size(calcWidth, calcHeight);
+        }
+}

samples/android/camera-preview/src/org/opencv/test/camerawriter/OpenCvNativeCameraView.java

+package org.opencv.test.camerawriter;
+
+import org.opencv.android.Utils;
+import org.opencv.core.Mat;
+import org.opencv.core.Size;
+import org.opencv.highgui.Highgui;
+import org.opencv.highgui.VideoCapture;
+
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.Canvas;
+import android.util.AttributeSet;
+import android.util.Log;
+
+/**
+ * This class is an implementation of a bridge between SurfaceView and native OpenCV camera.
+ * Due to the big amount of work done, by the base class this child is only responsible
+ * for creating camera, destroying camera and delivering frames while camera is enabled
+ */
+public class OpenCvNativeCameraView extends OpenCvCameraBridgeViewBase {
+
+        public static final String TAG = "OpenCvNativeCameraView";
+        private boolean mStopThread;
+        private Thread mThread;
+        private VideoCapture mCamera;
+
+
+    public OpenCvNativeCameraView(Context context, AttributeSet attrs) {
+                super(context, attrs);
+        }
+
+
+        @Override
+        protected void connectCamera(int width, int height) {
+
+                /* 1. We need to instantiate camera
+                 * 2. We need to start thread which will be getting frames
+                 */
+                /* First step - initialize camera connection */
+                initializeCamera(getWidth(), getHeight());
+
+                /* now we can start update thread */
+                mThread = new Thread(new CameraWorker(getWidth(), getHeight()));
+                mThread.start();
+        }
+
+        @Override
+        protected void disconnectCamera() {
+                /* 1. We need to stop thread which updating the frames
+                 * 2. Stop camera and release it
+                 */
+                try {
+                        mStopThread = true;
+                        mThread.join();
+                } catch (InterruptedException e) {
+                        e.printStackTrace();
+                } finally {
+                        mThread =  null;
+                        mStopThread = false;
+                }
+
+                /* Now release camera */
+                releaseCamera();
+
+        }
+
+        private void initializeCamera(int width, int height) {
+        mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID);
+        //TODO: improve error handling
+
+        java.util.List<Size> sizes = mCamera.getSupportedPreviewSizes();
+
+        /* Select the size that fits surface considering maximum size allowed */
+        Size frameSize = calculateCameraFrameSize(sizes, width, height);
+
+
+        double frameWidth = frameSize.width;
+        double frameHeight = frameSize.height;
+
+
+        mCamera.set(Highgui.CV_CAP_PROP_FRAME_WIDTH, frameWidth);
+        mCamera.set(Highgui.CV_CAP_PROP_FRAME_HEIGHT, frameHeight);
+
+        mFrameWidth = (int)frameWidth;
+        mFrameHeight = (int)frameHeight;
+
+        Log.i(TAG, "Selected camera frame size = (" + mFrameWidth + ", " + mFrameHeight + ")");
+        }
+
+        private void releaseCamera() {
+                if (mCamera != null) {
+                        mCamera.release();
+                }
+        }
+
+        private class CameraWorker implements Runnable {
+
+            private Mat mRgba = new Mat();
+            private int mWidth;
+            private int mHeight;
+
+            CameraWorker(int w, int h) {
+		mWidth = w;
+		mHeight = h;
+            }
+
+                @Override
+                public void run() {
+                        Mat modified;
+
+
+                        do {
+                                if (!mCamera.grab()) {
+                                        Log.e(TAG, "Camera frame grab failed");
+                                        break;
+                                }
+                    mCamera.retrieve(mRgba, Highgui.CV_CAP_ANDROID_COLOR_FRAME_RGBA);
+
+                    deliverAndDrawFrame(mRgba);
+
+                        } while (!mStopThread);
+
+                }
+        }
+
+}