ShapeDetection: use mojom::Bitmap for mojo interface.

content/public/android/java/src/org/chromium/content/browser/shapedetection/FaceDetectionImpl.java

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.content.browser.shapedetection;
 
 import android.graphics.Bitmap;
+import android.graphics.Bitmap.Config;
 import android.graphics.PointF;
 import android.media.FaceDetector;
 import android.media.FaceDetector.Face;
 
 import org.chromium.base.Log;
 import org.chromium.gfx.mojom.RectF;
 import org.chromium.mojo.system.MojoException;
-import org.chromium.mojo.system.SharedBufferHandle;
-import org.chromium.mojo.system.SharedBufferHandle.MapFlags;
 import org.chromium.shape_detection.mojom.FaceDetection;
 import org.chromium.shape_detection.mojom.FaceDetectionResult;
 import org.chromium.shape_detection.mojom.FaceDetectorOptions;
+import org.chromium.skia.mojom.ColorType;
 
 import java.nio.ByteBuffer;
 
 /**
  * Android implementation of the FaceDetection service defined in
  * services/shape_detection/public/interfaces/facedetection.mojom
  */
 public class FaceDetectionImpl implements FaceDetection {
     private static final String TAG = "FaceDetectionImpl";
     private static final int MAX_FACES = 32;
     private final boolean mFastMode;
     private final int mMaxFaces;
 
     FaceDetectionImpl(FaceDetectorOptions options) {
         mFastMode = options.fastMode;
         mMaxFaces = Math.min(options.maxDetectedFaces, MAX_FACES);
     }
 
+    private Config validConfig(int colorType) {
+        switch (colorType) {
+            case ColorType.ALPHA_8:
+                return Config.ALPHA_8;
+            case ColorType.RGB_565:
+                return Config.RGB_565;
+            case ColorType.ARGB_4444:
+                return Config.ARGB_4444;
+            case ColorType.RGBA_8888:
+            case ColorType.BGRA_8888:
+                return Config.ARGB_8888;
+        }
+        return null;
+    }
+
     @Override
-    public void detect(
-            SharedBufferHandle frameData, int width, int height, DetectResponse callback) {
+    public void detect(org.chromium.skia.mojom.Bitmap bitmapData, DetectResponse callback) {
+        int width = bitmapData.width;
+        int height = bitmapData.height;
+        Config bitmapConfig = validConfig(bitmapData.colorType);
         final long numPixels = (long) width * height;
         // TODO(xianglu): https://crbug.com/670028 homogeneize overflow checking.
-        if (!frameData.isValid() || width <= 0 || height <= 0 || numPixels > (Long.MAX_VALUE / 4)) {
+        if (bitmapData.pixelData == null || width <= 0 || height <= 0
+                || numPixels > (Long.MAX_VALUE / 4) || bitmapConfig == null) {
             Log.d(TAG, "Invalid argument(s).");
             callback.call(new FaceDetectionResult());
             return;
         }
 
-        ByteBuffer imageBuffer = frameData.map(0, numPixels * 4, MapFlags.none());
+        ByteBuffer imageBuffer = ByteBuffer.wrap(bitmapData.pixelData);
         if (imageBuffer.capacity() <= 0) {
-            Log.d(TAG, "Failed to map from SharedBufferHandle.");
+            Log.d(TAG, "Failed to wrap from Bitmap.");
             callback.call(new FaceDetectionResult());
             return;
         }
 
-        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+        Bitmap unPremultipliedBitmap;
+        if (bitmapData.colorType == ColorType.RGB_565) {
+            unPremultipliedBitmap = Bitmap.createBitmap(width, height, bitmapConfig);
 
-        // An int array is needed to construct a Bitmap. However the Bytebuffer
-        // we get from |sharedBufferHandle| is directly allocated and does not
-        // have a supporting array. Therefore we need to copy from |imageBuffer|
-        // to create this intermediate Bitmap.
-        // TODO(xianglu): Consider worker pool as appropriate threads.
-        // http://crbug.com/655814
-        bitmap.copyPixelsFromBuffer(imageBuffer);
+            // An int array is needed to construct a Bitmap. However the Bytebuffer
+            // we get from |bitmapData| is directly allocated and does not have a supporting array.
+            // Therefore we need to copy from |imageBuffer| to create this intermediate Bitmap.
+            // TODO(xianglu): Consider worker pool as appropriate threads.
+            // http://crbug.com/655814
+            unPremultipliedBitmap.copyPixelsFromBuffer(imageBuffer);
+        } else {
+            Bitmap bitmap = Bitmap.createBitmap(width, height, bitmapConfig);
 
-        // A Bitmap must be in 565 format for findFaces() to work. See
-        // http://androidxref.com/7.0.0_r1/xref/frameworks/base/media/java/android/media/FaceDetector.java#124
-        //
-        // It turns out that FaceDetector is not able to detect correctly if
-        // simply using pixmap.setConfig(). The reason might be that findFaces()
-        // needs non-premultiplied ARGB arrangement, while the alpha type in the
-        // original image is premultiplied. We can use getPixels() which does
-        // the unmultiplication while copying to a new array. See
-        // http://androidxref.com/7.0.0_r1/xref/frameworks/base/graphics/java/android/graphics/Bitmap.java#538
-        int[] pixels = new int[width * height];
-        bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
-        Bitmap unPremultipliedBitmap =
-                Bitmap.createBitmap(pixels, width, height, Bitmap.Config.RGB_565);
+            bitmap.copyPixelsFromBuffer(imageBuffer);
+
+            // A Bitmap must be in 565 format for findFaces() to work. See
+            // http://androidxref.com/7.0.0_r1/xref/frameworks/base/media/java/android/media/FaceDetector.java#124
+            //
+            // It turns out that FaceDetector is not able to detect correctly if
+            // simply using pixmap.setConfig(). The reason might be that findFaces()
+            // needs non-premultiplied ARGB arrangement, while the alpha type in the
+            // original image is premultiplied. We can use getPixels() which does
+            // the unmultiplication while copying to a new array. See
+            // http://androidxref.com/7.0.0_r1/xref/frameworks/base/graphics/java/android/graphics/Bitmap.java#538
+            int[] pixels = new int[width * height];
+            bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
+            unPremultipliedBitmap =
+                    Bitmap.createBitmap(pixels, width, height, Bitmap.Config.RGB_565);
+        }

[mcasas, 2017/01/24 20:48:31]

Similar comments to the others in this section: we don't
use RGB_565 right now and the code in the first branch
should be tested.  Also, there is the issue of the 
directness [1] of |bitmapData|, which you are not 
explicitly testing for nor asserting, so it might well be
that the RGB_565 branch would not work.  

Since the purpose of this CL is to migrate to mojom.Bitmap, 
I wouldn't add untested code, and just make sure that what
we receive is RGBA/BGRA_8888, again with the same
structure as before:

        if (bitmapData.colorType != ColorType.RGBA_8888
                && bitmapData.colorType != ColorType.BGRA_8888) {
            Log.e(TAG, "Unsupported bitmap pixel format");
            callback.call(new BarcodeDetectionResult[0]);
            return;
        }


And add a TODO+bug to "use |bitmapData| directly for
|unPremultipliedBitmap| to spare a copy" or some such 
description, which will be coded and tested subsequently
but separatedly.

[1] https://developer.android.com/reference/java/nio/ByteBuffer.html#isDirect()

 
         FaceDetector detector = new FaceDetector(width, height, mMaxFaces);
         Face[] detectedFaces = new Face[mMaxFaces];
         // findFaces() will stop at |mMaxFaces|.
         final int numberOfFaces = detector.findFaces(unPremultipliedBitmap, detectedFaces);
 
         FaceDetectionResult faceDetectionResult = new FaceDetectionResult();
         faceDetectionResult.boundingBoxes = new RectF[numberOfFaces];
         for (int i = 0; i < numberOfFaces; i++) {
             final Face face = detectedFaces[i];
@@ skipping 15 matching lines @@
     }
 
     @Override
     public void close() {}
 
     @Override
     public void onConnectionError(MojoException e) {
         close();
     }
 }