android: use .getRowStride() in JavaCamera2View

modules/core/misc/java/src/java/core+Mat.java

@@ -41,6 +41,15 @@ public class Mat {
         nativeObj = n_Mat(rows, cols, type, data);
     }
 
+    //
+    // C++: Mat::Mat(int rows, int cols, int type, void* data, size_t step)
+    //
+
+    // javadoc: Mat::Mat(rows, cols, type, data, step)
+    public Mat(int rows, int cols, int type, ByteBuffer data, long step) {
+        nativeObj = n_Mat(rows, cols, type, data, step);
+    }
+
     //
     // C++: Mat::Mat(Size size, int type)
     //
@@ -1136,6 +1145,9 @@ public class Mat {
     // C++: Mat::Mat(int rows, int cols, int type, void* data)
     private static native long n_Mat(int rows, int cols, int type, ByteBuffer data);
 
+    // C++: Mat::Mat(int rows, int cols, int type, void* data, size_t step)
+    private static native long n_Mat(int rows, int cols, int type, ByteBuffer data, long step);
+
     // C++: Mat::Mat(Size size, int type)
     private static native long n_Mat(double size_width, double size_height, int type);
 

modules/core/misc/java/test/MatTest.java

@@ -1246,4 +1246,22 @@ public class MatTest extends OpenCVTestCase {
         assertEquals(1, bbuf.get(4095));
     }
 
+    public void testMatFromByteBufferWithStep() {
+        ByteBuffer bbuf = ByteBuffer.allocateDirect(80*64);
+        bbuf.putInt(0x01010101);
+        bbuf.putInt(64, 0x02020202);
+        bbuf.putInt(80, 0x03030303);
+        Mat m = new Mat(64, 64, CvType.CV_8UC1, bbuf, 80);
+        assertEquals(8, Core.countNonZero(m));
+        Core.add(m, new Scalar(5), m);
+        assertEquals(4096, Core.countNonZero(m));
+        m.release();
+        assertEquals(6, bbuf.get(0));
+        assertEquals(5, bbuf.get(63));
+        assertEquals(2, bbuf.get(64));
+        assertEquals(0, bbuf.get(79));
+        assertEquals(8, bbuf.get(80));
+        assertEquals(5, bbuf.get(63*80 + 63));
+    }
+
 }

modules/java/generator/android-21/java/org/opencv/android/JavaCamera2View.java

@@ -332,8 +332,10 @@ public class JavaCamera2View extends CameraBridgeViewBase {
             Image.Plane[] planes = mImage.getPlanes();
             int w = mImage.getWidth();
             int h = mImage.getHeight();
+            assert(planes[0].getPixelStride() == 1);
             ByteBuffer y_plane = planes[0].getBuffer();
-            mGray = new Mat(h, w, CvType.CV_8UC1, y_plane);
+            int y_plane_step = planes[0].getRowStride();
+            mGray = new Mat(h, w, CvType.CV_8UC1, y_plane, y_plane_step);
             return mGray;
         }
 
@@ -349,11 +351,14 @@ public class JavaCamera2View extends CameraBridgeViewBase {
                 assert(planes[0].getPixelStride() == 1);
                 assert(planes[2].getPixelStride() == 2);
                 ByteBuffer y_plane = planes[0].getBuffer();
+                int y_plane_step = planes[0].getRowStride();
                 ByteBuffer uv_plane1 = planes[1].getBuffer();
+                int uv_plane1_step = planes[1].getRowStride();
                 ByteBuffer uv_plane2 = planes[2].getBuffer();
-                Mat y_mat = new Mat(h, w, CvType.CV_8UC1, y_plane);
-                Mat uv_mat1 = new Mat(h / 2, w / 2, CvType.CV_8UC2, uv_plane1);
-                Mat uv_mat2 = new Mat(h / 2, w / 2, CvType.CV_8UC2, uv_plane2);
+                int uv_plane2_step = planes[2].getRowStride();
+                Mat y_mat = new Mat(h, w, CvType.CV_8UC1, y_plane, y_plane_step);
+                Mat uv_mat1 = new Mat(h / 2, w / 2, CvType.CV_8UC2, uv_plane1, uv_plane1_step);
+                Mat uv_mat2 = new Mat(h / 2, w / 2, CvType.CV_8UC2, uv_plane2, uv_plane2_step);
                 long addr_diff = uv_mat2.dataAddr() - uv_mat1.dataAddr();
                 if (addr_diff > 0) {
                     assert(addr_diff == 1);
@@ -369,30 +374,45 @@ public class JavaCamera2View extends CameraBridgeViewBase {
                 ByteBuffer u_plane = planes[1].getBuffer();
                 ByteBuffer v_plane = planes[2].getBuffer();
 
-                y_plane.get(yuv_bytes, 0, w*h);
+                int yuv_bytes_offset = 0;
+
+                int y_plane_step = planes[0].getRowStride();
+                if (y_plane_step == w) {
+                    y_plane.get(yuv_bytes, 0, w*h);
+                    yuv_bytes_offset = w*h;
+                } else {
+                    int padding = y_plane_step - w;
+                    for (int i = 0; i < h; i++){
+                        y_plane.get(yuv_bytes, yuv_bytes_offset, w);
+                        yuv_bytes_offset += w;
+                        if (i < h - 1) {
+                            y_plane.position(y_plane.position() + padding);
+                        }
+                    }
+                    assert(yuv_bytes_offset == w * h);
+                }
 
                 int chromaRowStride = planes[1].getRowStride();
                 int chromaRowPadding = chromaRowStride - w/2;
 
-                int offset = w*h;
                 if (chromaRowPadding == 0){
                     // When the row stride of the chroma channels equals their width, we can copy
                     // the entire channels in one go
-                    u_plane.get(yuv_bytes, offset, w*h/4);
-                    offset += w*h/4;
-                    v_plane.get(yuv_bytes, offset, w*h/4);
+                    u_plane.get(yuv_bytes, yuv_bytes_offset, w*h/4);
+                    yuv_bytes_offset += w*h/4;
+                    v_plane.get(yuv_bytes, yuv_bytes_offset, w*h/4);
                 } else {
                     // When not equal, we need to copy the channels row by row
                     for (int i = 0; i < h/2; i++){
-                        u_plane.get(yuv_bytes, offset, w/2);
-                        offset += w/2;
+                        u_plane.get(yuv_bytes, yuv_bytes_offset, w/2);
+                        yuv_bytes_offset += w/2;
                         if (i < h/2-1){
                             u_plane.position(u_plane.position() + chromaRowPadding);
                         }
                     }
                     for (int i = 0; i < h/2; i++){
-                        v_plane.get(yuv_bytes, offset, w/2);
-                        offset += w/2;
+                        v_plane.get(yuv_bytes, yuv_bytes_offset, w/2);
+                        yuv_bytes_offset += w/2;
                         if (i < h/2-1){
                             v_plane.position(v_plane.position() + chromaRowPadding);
                         }

modules/java/generator/src/cpp/Mat.cpp

@@ -74,7 +74,7 @@ JNIEXPORT jlong JNICALL Java_org_opencv_core_Mat_n_1Mat__IIILjava_nio_ByteBuffer
 JNIEXPORT jlong JNICALL Java_org_opencv_core_Mat_n_1Mat__IIILjava_nio_ByteBuffer_2
   (JNIEnv* env, jclass, jint rows, jint cols, jint type, jobject data)
 {
-    static const char method_name[] = "Mat::n_1Mat__IIILByteBuffer()";
+    static const char method_name[] = "Mat::n_1Mat__IIILjava_nio_ByteBuffer_2()";
     try {
         LOGD("%s", method_name);
         return (jlong) new Mat( rows, cols, type, (void*)env->GetDirectBufferAddress(data) );
@@ -88,6 +88,32 @@ JNIEXPORT jlong JNICALL Java_org_opencv_core_Mat_n_1Mat__IIILjava_nio_ByteBuffer
 }
 
 
+/*
+ * Class:     org_opencv_core_Mat
+ * Method:    n_Mat
+ * Signature: (IIILjava/nio/ByteBuffer;J)J
+ *
+ * Mat::Mat(int rows, int cols, int type, void* data, size_t step)
+ */
+JNIEXPORT jlong JNICALL Java_org_opencv_core_Mat_n_1Mat__IIILjava_nio_ByteBuffer_2J
+  (JNIEnv* env, jclass, jint rows, jint cols, jint type, jobject data, jlong step);
+
+JNIEXPORT jlong JNICALL Java_org_opencv_core_Mat_n_1Mat__IIILjava_nio_ByteBuffer_2J
+  (JNIEnv* env, jclass, jint rows, jint cols, jint type, jobject data, jlong step)
+{
+    static const char method_name[] = "Mat::n_1Mat__IIILjava_nio_ByteBuffer_2J()";
+    try {
+        LOGD("%s", method_name);
+        return (jlong) new Mat(rows, cols, type, (void*)env->GetDirectBufferAddress(data), (size_t)step);
+    } catch(const std::exception &e) {
+        throwJavaException(env, &e, method_name);
+    } catch (...) {
+        throwJavaException(env, 0, method_name);
+    }
+
+    return 0;
+}
+
 
 //
 //   Mat::Mat(int rows, int cols, int type)