captureSnapshot() API

README.md

@@ -7,6 +7,7 @@
 - *simpler APIs*
 - *docs and comments in code*
 - *introduced sessionType (picture or video), replacing Method and Permissions stuff* 
+- *new `captureSnapshot` API*
 - *new `setLocation` and `setWhiteBalance` APIs*
 - *option to pass a `File` when recording a video*
 - *introduced a smart measuring and sizing behavior, replacing bugged `adjustViewBounds`*
@@ -51,11 +52,11 @@ CameraKit is an easy to use utility to work with the Android Camera APIs. Everyt
 - System permission handling
 - Dynamic sizing behavior
   - Create a `CameraView` of any size (not just presets!)
-  - Or let it adapt to the sensor preview size
+  - Center inside or center crop behaviors
   - Automatic output cropping to match your `CameraView` bounds
 - Multiple capture methods
-  - While taking pictures, image is captured normally using the camera APIs.
+  - Take high-resolution pictures with `capturePicture`
-  - While shooting videos, image is captured as a freeze frame of the `CameraView` preview (similar to SnapChat and Instagram)
+  - Take quick snapshots as a freeze frame of the preview with `captureSnapshot`, even while recording videos (similar to SnapChat and Instagram)
 - Built-in tap to focus
 - `CameraUtils` to help with Bitmaps and orientations
 - EXIF support
@@ -109,7 +110,7 @@ camera.setCameraListener(new CameraListener() {
     @Override
     public void onPictureTaken(byte[] picture) {
         // Create a bitmap or a file...
-        // CameraUtils will read EXIF orientation for you.
+        // CameraUtils will read EXIF orientation for you, in a worker thread.
         CameraUtils.decodeBitmap(picture, ...);
     }
 });
@@ -117,6 +118,8 @@ camera.setCameraListener(new CameraListener() {
 camera.captureImage();
 ```
 
+You can also use `camera.captureSnapshot()` to capture a preview frame. This is faster, though has lower quality, and can be used while recording videos.
+
 ### Capturing Video
 
 TODO: test size and orientation stuff.

camerakit/src/main/api16/com/flurgle/camerakit/Camera1.java

@@ -63,6 +63,7 @@ class Camera1 extends CameraImpl {
     private ConstantMapper.MapperImpl mMapper = new ConstantMapper.Mapper1();
     private boolean mIsSetup = false;
     private boolean mIsCapturingImage = false;
+    private boolean mIsCapturingVideo = false;
     private final Object mLock = new Object();
 
 
@@ -360,57 +361,62 @@ class Camera1 extends CameraImpl {
     void captureImage() {
         if (mIsCapturingImage) return;
         if (!isCameraOpened()) return;
-        switch (mSessionType) {
+        if (mIsCapturingVideo || mSessionType == SESSION_TYPE_VIDEO) {
-            case SESSION_TYPE_PICTURE:
+            captureSnapshot();
-                // Set boolean to wait for image callback
+            return;
-                mIsCapturingImage = true;
+        }
-                synchronized (mLock) {
+
-                    Camera.Parameters parameters = mCamera.getParameters();
+        // Set boolean to wait for image callback
-                    parameters.setRotation(computeExifOrientation());
+        mIsCapturingImage = true;
-                    mCamera.setParameters(parameters);
+        synchronized (mLock) {
-                }
+            Camera.Parameters parameters = mCamera.getParameters();
-                mCamera.takePicture(null, null, null,
+            parameters.setRotation(computeExifRotation());
-                    new Camera.PictureCallback() {
+            // TODO: add flipping
-                        @Override
+            mCamera.setParameters(parameters);
-                        public void onPictureTaken(byte[] data, Camera camera) {
+        }
-                            mCameraListener.onPictureTaken(data);
+        mCamera.takePicture(null, null, null,
-                            mIsCapturingImage = false;
+                new Camera.PictureCallback() {
-                            camera.startPreview(); // This is needed, read somewhere in the docs.
-                        }
-                    });
-                break;
-
-            case SESSION_TYPE_VIDEO:
-                // If we are in a video session, camera captures are fast captures coming
-                // from the preview stream.
-                // TODO: will this work while recording a video? test...
-                mIsCapturingImage = true;
-                mCamera.setOneShotPreviewCallback(new Camera.PreviewCallback() {
                     @Override
-                    public void onPreviewFrame(final byte[] data, Camera camera) {
+                    public void onPictureTaken(byte[] data, Camera camera) {
-                        // Got to rotate the preview frame, since byte[] data here does not include
+                        mCameraListener.onPictureTaken(data);
-                        // EXIF tags automatically set by camera. So either we add EXIF, or we rotate.
+                        mIsCapturingImage = false;
-                        Camera.Parameters params = mCamera.getParameters();
+                        camera.startPreview(); // This is needed, read somewhere in the docs.
-                        final int rotation = computeExifOrientation();
-                        final boolean flip = rotation % 180 != 0;
-                        final int preWidth = mPreviewSize.getWidth();
-                        final int preHeight = mPreviewSize.getHeight();
-                        final int postWidth = flip ? preHeight : preWidth;
-                        final int postHeight = flip ? preWidth : preHeight;
-                        final int format = params.getPreviewFormat();
-                        new Thread(new Runnable() {
-                            @Override
-                            public void run() {
-                                byte[] rotatedData = RotationHelper.rotate(data, preWidth, preHeight, rotation);
-                                YuvImage yuv = new YuvImage(rotatedData, format, postWidth, postHeight, null);
-                                mCameraListener.processYuvImage(yuv);
-                                mIsCapturingImage = false;
-                            }
-                        }).start();
                     }
                 });
-                break;
+    }
-        }
+
+
+    @Override
+    void captureSnapshot() {
+        if (mIsCapturingImage) return;
+        if (!isCameraOpened()) return;
+        // TODO: will this work while recording a video? test...
+        mIsCapturingImage = true;
+        mCamera.setOneShotPreviewCallback(new Camera.PreviewCallback() {
+            @Override
+            public void onPreviewFrame(final byte[] data, Camera camera) {
+                // Got to rotate the preview frame, since byte[] data here does not include
+                // EXIF tags automatically set by camera. So either we add EXIF, or we rotate.
+                // TODO: add exif, and also care about flipping.
+                Camera.Parameters params = mCamera.getParameters();
+                final int rotation = computeExifRotation();
+                final boolean flip = rotation % 180 != 0;
+                final int preWidth = mPreviewSize.getWidth();
+                final int preHeight = mPreviewSize.getHeight();
+                final int postWidth = flip ? preHeight : preWidth;
+                final int postHeight = flip ? preWidth : preHeight;
+                final int format = params.getPreviewFormat();
+                new Thread(new Runnable() {
+                    @Override
+                    public void run() {
+                        byte[] rotatedData = RotationHelper.rotate(data, preWidth, preHeight, rotation);
+                        YuvImage yuv = new YuvImage(rotatedData, format, postWidth, postHeight, null);
+                        mCameraListener.processYuvImage(yuv);
+                        mIsCapturingImage = false;
+                    }
+                }).start();
+            }
+        });
     }
 
     @Override
@@ -458,8 +464,9 @@ class Camera1 extends CameraImpl {
     /**
      * Returns the orientation to be set as a exif tag. This is already managed by
      * the camera APIs as long as you call {@link Camera.Parameters#setRotation(int)}.
+     * This ignores flipping for facing camera.
      */
-    private int computeExifOrientation() {
+    private int computeExifRotation() {
         return (mDeviceOrientation + mSensorOffset) % 360;
     }
 
@@ -507,7 +514,10 @@ class Camera1 extends CameraImpl {
     @Override
     void startVideo(@NonNull File videoFile) {
         mVideoFile = videoFile;
+        if (mIsCapturingVideo) return;
+        if (!isCameraOpened()) return;
         if (mSessionType == SESSION_TYPE_VIDEO) {
+            mIsCapturingVideo = true;
             initMediaRecorder();
             try {
                 mMediaRecorder.prepare();
@@ -525,6 +535,7 @@ class Camera1 extends CameraImpl {
 
     @Override
     void endVideo() {
+        mIsCapturingVideo = false;
         mMediaRecorder.stop();
         mMediaRecorder.release();
         mMediaRecorder = null;

camerakit/src/main/api21/com/flurgle/camerakit/Camera2.java

@@ -182,6 +182,11 @@ class Camera2 extends CameraImpl {
 
     }
 
+    @Override
+    void captureSnapshot() {
+
+    }
+
     @Override
     void startVideo(@NonNull File videoFile) {
 

camerakit/src/main/base/com/flurgle/camerakit/CameraImpl.java

@@ -33,6 +33,7 @@ abstract class CameraImpl implements PreviewImpl.SurfaceCallback {
     abstract void setLocation(double latitude, double longitude);
 
     abstract void captureImage();
+    abstract void captureSnapshot();
     abstract void startVideo(@NonNull File file);
     abstract void endVideo();
 

camerakit/src/main/java/com/flurgle/camerakit/CameraUtils.java

@@ -52,6 +52,7 @@ public class CameraUtils {
             public void run() {
 
                 int orientation = 0;
+                boolean flip = false;
                 try {
                     // http://sylvana.net/jpegcrop/exif_orientation.html
                     ExifInterface exif = new ExifInterface(new ByteArrayInputStream(source));
@@ -75,16 +76,24 @@ public class CameraUtils {
 
                         default: orientation = 0;
                     }
+
+                    flip = exifOrientation == ExifInterface.ORIENTATION_FLIP_HORIZONTAL ||
+                            exifOrientation == ExifInterface.ORIENTATION_FLIP_VERTICAL ||
+                            exifOrientation == ExifInterface.ORIENTATION_TRANSPOSE ||
+                            exifOrientation == ExifInterface.ORIENTATION_TRANSVERSE;
+
                 } catch (IOException e) {
                     e.printStackTrace();
                     orientation = 0;
+                    flip = false;
                 }
 
 
                 Bitmap bitmap = BitmapFactory.decodeByteArray(source, 0, source.length);
-                if (orientation != 0) {
+                if (orientation != 0 || flip) {
                     Matrix matrix = new Matrix();
                     matrix.setRotate(orientation);
+                    // matrix.postScale(1, -1) Flip... needs testing.
                     Bitmap temp = bitmap;
                     bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
                     temp.recycle();

camerakit/src/main/java/com/flurgle/camerakit/CameraView.java

@@ -660,6 +660,9 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
 
     /**
      * Set the current session type to either picture or video.
+     * When sessionType is video,
+     * - {@link #startCapturingVideo(File)} will not throw any exception
+     * - {@link #captureImage()} will fallback to {@link #captureSnapshot()}
      *
      * @see CameraKit.Constants#SESSION_TYPE_PICTURE
      * @see CameraKit.Constants#SESSION_TYPE_VIDEO
@@ -773,11 +776,38 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
     }
 
 
+    /**
+     * Asks the camera to capture an image of the current scene.
+     * This will trigger {@link CameraListener#onPictureTaken(byte[])} if a listener
+     * was registered.
+     *
+     * Note that if sessionType is {@link CameraKit.Constants#SESSION_TYPE_VIDEO}, this
+     * falls back to {@link #captureSnapshot()} (that is, we will capture a preview frame).
+     *
+     * @see #captureSnapshot()
+     */
     public void captureImage() {
         mCameraImpl.captureImage();
     }
 
 
+    /**
+     * Asks the camera to capture a snapshot of the current preview.
+     * This eventually triggers {@link CameraListener#onPictureTaken(byte[])} if a listener
+     * was registered.
+     *
+     * The difference with {@link #captureImage()} is that:
+     * - this capture is faster, so it might be better on slower cameras, though the result can be
+     *   generally blurry or low quality
+     * - this can be called even if sessionType is {@link CameraKit.Constants#SESSION_TYPE_VIDEO}
+     *
+     * @see #captureImage()
+     */
+    public void captureSnapshot() {
+        mCameraImpl.captureSnapshot();
+    }
+
+
     /**
      * Starts recording a video with selected options, in a file called
      * "video.mp4" in the default folder.
@@ -824,6 +854,7 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         return mCameraImpl != null ? mCameraImpl.getPreviewSize() : null;
     }
 
+
     /**
      * Returns the size used for the capture,
      * or null if it hasn't been computed yet (for example if the surface is not ready).
@@ -834,6 +865,19 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
         return mCameraImpl != null ? mCameraImpl.getCaptureSize() : null;
     }
 
+
+    /**
+     * Returns the size used for capturing snapshots.
+     * This is equal to {@link #getPreviewSize()}.
+     *
+     * @return a Size
+     */
+    @Nullable
+    public Size getSnapshotSize() {
+        return getPreviewSize();
+    }
+
+
     private void requestPermissions(boolean requestCamera, boolean requestAudio) {
         Activity activity = null;
         Context context = getContext();