/*
- * Copyright 2008 ZXing authors
+ * Copyright (C) 2008 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
package com.google.zxing.client.android;
+import com.google.zxing.ResultPoint;
+
import android.content.Context;
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
-import android.graphics.Canvas;
+import android.graphics.PixelFormat;
import android.graphics.Point;
import android.graphics.Rect;
-import android.hardware.CameraDevice;
+import android.hardware.Camera;
+import android.os.Build;
+import android.os.Handler;
+import android.os.Message;
import android.util.Log;
import android.view.Display;
+import android.view.SurfaceHolder;
import android.view.WindowManager;
-import com.google.zxing.ResultPoint;
-import com.tomgibara.android.camera.BitmapCamera;
-import com.tomgibara.android.camera.CameraSource;
+
+import java.io.IOException;
/**
- * This object wraps the CameraDevice and expects to be the only one talking to it. The
- * implementation encapsulates the steps needed to take preview-sized images and well as high
- * resolution stills.
+ * This object wraps the Camera service object and expects to be the only one talking to it. The
+ * implementation encapsulates the steps needed to take preview-sized images, which are used for
+ * both preview and decoding.
*
* @author dswitkin@google.com (Daniel Switkin)
*/
final class CameraManager {
-
private static final String TAG = "CameraManager";
+ private static final int MIN_FRAME_WIDTH = 240;
+ private static final int MIN_FRAME_HEIGHT = 240;
+ private static final int MAX_FRAME_WIDTH = 480;
+ private static final int MAX_FRAME_HEIGHT = 360;
+ private static CameraManager cameraManager;
+ private Camera camera;
private final Context context;
- private Point cameraResolution;
- private Point stillResolution;
- private Point previewResolution;
- private int stillMultiplier;
private Point screenResolution;
+ private Point cameraResolution;
private Rect framingRect;
- private Bitmap bitmap;
- // TODO switch back to CameraDevice later
- // private CameraDevice camera;
- private CameraSource cameraSource;
- // end TODO
- private final CameraDevice.CaptureParams params;
- private boolean previewMode;
- private boolean usePreviewForDecode;
+ private Handler previewHandler;
+ private int previewMessage;
+ private Handler autoFocusHandler;
+ private int autoFocusMessage;
+ private boolean initialized;
+ private boolean previewing;
+ private int previewFormat;
+ private String previewFormatString;
+ private boolean useOneShotPreviewCallback;
- CameraManager(Context context) {
- this.context = context;
- getScreenResolution();
- calculateStillResolution();
- calculatePreviewResolution();
+ /**
+ * Preview frames are delivered here, which we pass on to the registered handler. Make sure to
+ * clear the handler so it will only receive one message.
+ */
+ private final Camera.PreviewCallback previewCallback = new Camera.PreviewCallback() {
+ public void onPreviewFrame(byte[] data, Camera camera) {
+ if (!useOneShotPreviewCallback) {
+ camera.setPreviewCallback(null);
+ }
+ if (previewHandler != null) {
+ Message message = previewHandler.obtainMessage(previewMessage, cameraResolution.x,
+ cameraResolution.y, data);
+ message.sendToTarget();
+ previewHandler = null;
+ }
+ }
+ };
- usePreviewForDecode = true;
- setUsePreviewForDecode(false);
+ /**
+ * Autofocus callbacks arrive here, and are dispatched to the Handler which requested them.
+ */
+ private final Camera.AutoFocusCallback autoFocusCallback = new Camera.AutoFocusCallback() {
+ public void onAutoFocus(boolean success, Camera camera) {
+ if (autoFocusHandler != null) {
+ Message message = autoFocusHandler.obtainMessage(autoFocusMessage, success);
+ // Simulate continuous autofocus by sending a focus request every 1.5 seconds.
+ autoFocusHandler.sendMessageDelayed(message, 1500L);
+ autoFocusHandler = null;
+ }
+ }
+ };
- // TODO switch back to CameraDevice later
- // camera = null;
- Bitmap fakeBitmap = BitmapFactory.decodeFile("/tmp/barcode.jpg");
- if (fakeBitmap == null) {
- throw new RuntimeException("/tmp/barcode.jpg was not found");
+ /**
+ * Initializes this static object with the Context of the calling Activity.
+ *
+ * @param context The Activity which wants to use the camera.
+ */
+ public static void init(Context context) {
+ if (cameraManager == null) {
+ cameraManager = new CameraManager(context);
}
- cameraSource = new BitmapCamera(fakeBitmap, stillResolution.x, stillResolution.y);
- // end TODO
+ }
+
+ /**
+ * Gets the CameraManager singleton instance.
+ *
+ * @return A reference to the CameraManager singleton.
+ */
+ public static CameraManager get() {
+ return cameraManager;
+ }
+
+ private CameraManager(Context context) {
+ this.context = context;
+ camera = null;
+ initialized = false;
+ previewing = false;
- params = new CameraDevice.CaptureParams();
+ // Camera.setOneShotPreviewCallback() has a race condition in Cupcake, so we use the older
+ // Camera.setPreviewCallback() on 1.5 and earlier. For Donut and later, we need to use
+ // the more efficient one shot callback, as the older one can swamp the system and cause it
+ // to run out of memory. We can't use SDK_INT because it was introduced in the Donut SDK.
+ if (Integer.parseInt(Build.VERSION.SDK) <= Build.VERSION_CODES.CUPCAKE) {
+ useOneShotPreviewCallback = false;
+ } else {
+ useOneShotPreviewCallback = true;
+ }
}
- public void openDriver() {
-// TODO switch back to CameraDevice later
-// if (camera == null) {
-// camera = CameraDevice.open();
-// // If we're reopening the camera, we need to reset the capture params.
-// previewMode = false;
-// setPreviewMode(true);
-// }
-// end TODO
+ /**
+ * Opens the camera driver and initializes the hardware parameters.
+ *
+ * @param holder The surface object which the camera will draw preview frames into.
+ * @throws IOException Indicates the camera driver failed to open.
+ */
+ public void openDriver(SurfaceHolder holder) throws IOException {
+ if (camera == null) {
+ camera = Camera.open();
+ camera.setPreviewDisplay(holder);
+
+ if (!initialized) {
+ initialized = true;
+ getScreenResolution();
+ }
+
+ setCameraParameters();
+ }
}
+ /**
+ * Closes the camera driver if still in use.
+ */
public void closeDriver() {
- // TODO switch back to CameraDevice later
- // if (camera != null) {
- // camera.close();
- // camera = null;
- // }
- // end TODO
+ if (camera != null) {
+ camera.release();
+ camera = null;
+ }
}
- public void capturePreview(Canvas canvas) {
- setPreviewMode(true);
- // TODO switch back to CameraDevice later
- // camera.capture(canvas);
- cameraSource.capture(canvas);
- // end TODO
+ /**
+ * Asks the camera hardware to begin drawing preview frames to the screen.
+ */
+ public void startPreview() {
+ if (camera != null && !previewing) {
+ camera.startPreview();
+ previewing = true;
+ }
}
- public Bitmap captureStill() {
- setPreviewMode(usePreviewForDecode);
- Canvas canvas = new Canvas(bitmap);
- // TODO switch back to CameraDevice later
- // camera.capture(canvas);
- cameraSource.capture(canvas);
- // end TODO
- return bitmap;
+ /**
+ * Tells the camera to stop drawing preview frames.
+ */
+ public void stopPreview() {
+ if (camera != null && previewing) {
+ if (!useOneShotPreviewCallback) {
+ camera.setPreviewCallback(null);
+ }
+ camera.stopPreview();
+ previewHandler = null;
+ autoFocusHandler = null;
+ previewing = false;
+ }
}
/**
- * This method exists to help us evaluate how to best set up and use the camera.
- * @param usePreview Decode at preview resolution if true, else use still resolution.
+ * A single preview frame will be returned to the handler supplied. The data will arrive as byte[]
+ * in the message.obj field, with width and height encoded as message.arg1 and message.arg2,
+ * respectively.
+ *
+ * @param handler The handler to send the message to.
+ * @param message The what field of the message to be sent.
*/
- public void setUsePreviewForDecode(boolean usePreview) {
- if (usePreviewForDecode != usePreview) {
- usePreviewForDecode = usePreview;
- if (usePreview) {
- Log.v(TAG, "Creating bitmap at screen resolution: " + screenResolution.x + "," +
- screenResolution.y);
- bitmap = Bitmap.createBitmap(screenResolution.x, screenResolution.y, false);
+ public void requestPreviewFrame(Handler handler, int message) {
+ if (camera != null && previewing) {
+ previewHandler = handler;
+ previewMessage = message;
+ if (useOneShotPreviewCallback) {
+ camera.setOneShotPreviewCallback(previewCallback);
} else {
- Log.v(TAG, "Creating bitmap at still resolution: " + stillResolution.x + "," +
- stillResolution.y);
- bitmap = Bitmap.createBitmap(stillResolution.x, stillResolution.y, false);
+ camera.setPreviewCallback(previewCallback);
}
}
}
+ /**
+ * Asks the camera hardware to perform an autofocus.
+ *
+ * @param handler The Handler to notify when the autofocus completes.
+ * @param message The message to deliver.
+ */
+ public void requestAutoFocus(Handler handler, int message) {
+ if (camera != null && previewing) {
+ autoFocusHandler = handler;
+ autoFocusMessage = message;
+ camera.autoFocus(autoFocusCallback);
+ }
+ }
+
/**
* Calculates the framing rect which the UI should draw to show the user where to place the
- * barcode. The actual captured image should be a bit larger than indicated because they might
- * frame the shot too tightly. This target helps with alignment as well as forces the user to hold
- * the device far enough away to ensure the image will be in focus.
+ * barcode. This target helps with alignment as well as forces the user to hold the device
+ * far enough away to ensure the image will be in focus.
*
* @return The rectangle to draw on screen in window coordinates.
*/
public Rect getFramingRect() {
if (framingRect == null) {
- int size = stillResolution.x * screenResolution.x / previewResolution.x;
- int leftOffset = (screenResolution.x - size) / 2;
- int topOffset = (screenResolution.y - size) / 2;
- framingRect = new Rect(leftOffset, topOffset, leftOffset + size, topOffset + size);
+ if (camera == null) {
+ return null;
+ }
+ int width = cameraResolution.x * 3 / 4;
+ if (width < MIN_FRAME_WIDTH) {
+ width = MIN_FRAME_WIDTH;
+ } else if (width > MAX_FRAME_WIDTH) {
+ width = MAX_FRAME_WIDTH;
+ }
+ int height = cameraResolution.y * 3 / 4;
+ if (height < MIN_FRAME_HEIGHT) {
+ height = MIN_FRAME_HEIGHT;
+ } else if (height > MAX_FRAME_HEIGHT) {
+ height = MAX_FRAME_HEIGHT;
+ }
+ int leftOffset = (cameraResolution.x - width) / 2;
+ int topOffset = (cameraResolution.y - height) / 2;
+ framingRect = new Rect(leftOffset, topOffset, leftOffset + width, topOffset + height);
Log.v(TAG, "Calculated framing rect: " + framingRect);
}
return framingRect;
*/
public Point[] convertResultPoints(ResultPoint[] points) {
Rect frame = getFramingRect();
- int frameSize = frame.width();
int count = points.length;
Point[] output = new Point[count];
for (int x = 0; x < count; x++) {
output[x] = new Point();
- if (usePreviewForDecode) {
- output[x].x = (int) (points[x].getX() + 0.5f);
- output[x].y = (int) (points[x].getY() + 0.5f);
- } else {
- output[x].x = frame.left + (int) (points[x].getX() * frameSize / stillResolution.x + 0.5f);
- output[x].y = frame.top + (int) (points[x].getY() * frameSize / stillResolution.y + 0.5f);
- }
+ output[x].x = frame.left + (int) (points[x].getX() + 0.5f);
+ output[x].y = frame.top + (int) (points[x].getY() + 0.5f);
}
return output;
}
/**
- * Images for the live preview are taken at low resolution in RGB. Other code depends
- * on the ability to call this method for free if the correct mode is already set.
+ * A factory method to build the appropriate LuminanceSource object based on the format
+ * of the preview buffers, as described by Camera.Parameters.
*
- * @param on Setting on true will engage preview mode, setting it false will request still mode.
+ * @param data A preview frame.
+ * @param width The width of the image.
+ * @param height The height of the image.
+ * @return A PlanarYUVLuminanceSource instance.
*/
- private void setPreviewMode(boolean on) {
- if (on != previewMode) {
- if (on) {
- params.type = 1; // preview
- params.srcWidth = previewResolution.x;
- params.srcHeight = previewResolution.y;
- params.leftPixel = (cameraResolution.x - params.srcWidth) / 2;
- params.topPixel = (cameraResolution.y - params.srcHeight) / 2;
- params.outputWidth = screenResolution.x;
- params.outputHeight = screenResolution.y;
- params.dataFormat = 2; // RGB565
- } else {
- params.type = 0; // still
- params.srcWidth = stillResolution.x * stillMultiplier;
- params.srcHeight = stillResolution.y * stillMultiplier;
- params.leftPixel = (cameraResolution.x - params.srcWidth) / 2;
- params.topPixel = (cameraResolution.y - params.srcHeight) / 2;
- params.outputWidth = stillResolution.x;
- params.outputHeight = stillResolution.y;
- params.dataFormat = 2; // RGB565
- }
- String captureType = on ? "preview" : "still";
- Log.v(TAG, "Setting params for " + captureType + ": srcWidth " + params.srcWidth +
- " srcHeight " + params.srcHeight + " leftPixel " + params.leftPixel + " topPixel " +
- params.topPixel + " outputWidth " + params.outputWidth + " outputHeight " +
- params.outputHeight);
- // TODO switch back to CameraDevice later
- // camera.setCaptureParams(params);
- // end TODO
- previewMode = on;
+ public PlanarYUVLuminanceSource buildLuminanceSource(byte[] data, int width, int height) {
+ Rect rect = getFramingRect();
+ switch (previewFormat) {
+ // This is the standard Android format which all devices are REQUIRED to support.
+ // In theory, it's the only one we should ever care about.
+ case PixelFormat.YCbCr_420_SP:
+ return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top,
+ rect.width(), rect.height());
+ // This format has never been seen in the wild, but is compatible as we only care
+ // about the Y channel, so allow it.
+ case PixelFormat.YCbCr_422_SP:
+ return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top,
+ rect.width(), rect.height());
+ default:
+ // The Samsung Moment incorrectly uses this variant instead of the 'sp' version.
+ // Fortunately, it too has all the Y data up front, so we can read it.
+ if (previewFormatString.equals("yuv420p")) {
+ return new PlanarYUVLuminanceSource(data, width, height, rect.left, rect.top,
+ rect.width(), rect.height());
+ }
}
+ throw new IllegalArgumentException("Unsupported picture format: " +
+ previewFormat + '/' + previewFormatString);
}
/**
- * This method determines how to take the highest quality image (i.e. the one which has the best
- * chance of being decoded) given the capabilities of the camera. It is a balancing act between
- * having enough resolution to read UPCs and having few enough pixels to keep the QR Code
- * processing fast. The result is the dimensions of the rectangle to capture from the center of
- * the sensor, plus a stillMultiplier which indicates whether we'll ask the driver to downsample
- * for us. This has the added benefit of keeping the memory footprint of the bitmap as small as
- * possible.
+ * Sets the camera up to take preview images which are used for both preview and decoding.
+ * We detect the preview format here so that buildLuminanceSource() can build an appropriate
+ * LuminanceSource subclass. In the future we may want to force YUV420SP as it's the smallest,
+ * and the planar Y can be used for barcode scanning without a copy in some cases.
*/
- private void calculateStillResolution() {
- cameraResolution = getMaximumCameraResolution();
- int minDimension = (cameraResolution.x < cameraResolution.y) ? cameraResolution.x :
- cameraResolution.y;
- int diagonalResolution = (int) Math.sqrt(cameraResolution.x * cameraResolution.x +
- cameraResolution.y * cameraResolution.y);
- float diagonalFov = getFieldOfView();
-
- // Determine the field of view in the smaller dimension, then calculate how large an object
- // would be at the minimum focus distance.
- float fov = diagonalFov * minDimension / diagonalResolution;
- double objectSize = Math.tan(Math.toRadians(fov / 2.0)) * getMinimumFocusDistance() * 2;
-
- // Let's assume the largest barcode we might photograph at this distance is 3 inches across. By
- // cropping to this size, we can avoid processing surrounding pixels, which helps with speed and
- // accuracy.
- // TODO(dswitkin): Handle a device with a great macro mode where objectSize < 4 inches.
- double crop = 3.0 / objectSize;
- int nativeResolution = (int) (minDimension * crop);
-
- // The camera driver can only capture images which are a multiple of eight, so it's necessary to
- // round up.
- nativeResolution = ((nativeResolution + 7) >> 3) << 3;
- if (nativeResolution > minDimension) {
- nativeResolution = minDimension;
- }
+ private void setCameraParameters() {
+ Camera.Parameters parameters = camera.getParameters();
+ Camera.Size size = parameters.getPreviewSize();
+ Log.v(TAG, "Default preview size: " + size.width + ", " + size.height);
+ previewFormat = parameters.getPreviewFormat();
+ previewFormatString = parameters.get("preview-format");
+ Log.v(TAG, "Default preview format: " + previewFormat + '/' + previewFormatString);
- // There's no point in capturing too much detail, so ask the driver to downsample. I haven't
- // tried a non-integer multiple, but it seems unlikely to work.
- double dpi = nativeResolution / objectSize;
- stillMultiplier = 1;
- if (dpi > 200) {
- stillMultiplier = (int) (dpi / 200 + 1);
- }
- stillResolution = new Point(nativeResolution, nativeResolution);
- Log.v(TAG, "FOV " + fov + " objectSize " + objectSize + " crop " + crop + " dpi " + dpi +
- " nativeResolution " + nativeResolution + " stillMultiplier " + stillMultiplier);
- }
+ // Ensure that the camera resolution is a multiple of 8, as the screen may not be.
+ // TODO: A better solution would be to request the supported preview resolutions
+ // and pick the best match, but this parameter is not standardized in Cupcake.
+ cameraResolution = new Point();
+ cameraResolution.x = (screenResolution.x >> 3) << 3;
+ cameraResolution.y = (screenResolution.y >> 3) << 3;
+ Log.v(TAG, "Setting preview size: " + cameraResolution.x + ", " + cameraResolution.y);
+ parameters.setPreviewSize(cameraResolution.x, cameraResolution.y);
- /**
- * The goal of the preview resolution is to show a little context around the framing rectangle
- * which is the actual captured area in still mode.
- */
- private void calculatePreviewResolution() {
- if (previewResolution == null) {
- int previewHeight = (int) (stillResolution.x * stillMultiplier * 1.5f);
- int previewWidth = previewHeight * screenResolution.x / screenResolution.y;
- previewWidth = ((previewWidth + 7) >> 3) << 3;
- if (previewWidth > cameraResolution.x) previewWidth = cameraResolution.x;
- previewHeight = previewWidth * screenResolution.y / screenResolution.x;
- previewResolution = new Point(previewWidth, previewHeight);
- Log.v(TAG, "previewWidth " + previewWidth + " previewHeight " + previewHeight);
- }
- }
-
- // FIXME(dswitkin): These three methods have temporary constants until the new Camera API can
- // provide the real values for the current device.
- // Temporary: the camera's maximum resolution in pixels.
- private static Point getMaximumCameraResolution() {
- return new Point(1280, 1024);
- }
+ // FIXME: This is a hack to turn the flash off on the Samsung Galaxy.
+ parameters.set("flash-value", 2);
- // Temporary: the diagonal field of view in degrees.
- private static float getFieldOfView() {
- return 60.0f;
- }
+ // This is the standard setting to turn the flash off that all devices should honor.
+ parameters.set("flash-mode", "off");
- // Temporary: the minimum focus distance in inches.
- private static float getMinimumFocusDistance() {
- return 6.0f;
+ camera.setParameters(parameters);
}
private Point getScreenResolution() {
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