Can capture video Mat buffers and display them in a Window

Signed-off-by: deadprogram <[email protected]>

core.cpp

@@ -10,6 +10,10 @@ void Mat_Delete(Mat m) {
     delete m;
 }
 
+int Mat_Empty(Mat m) {
+    return m->empty();
+}
+
 // MatVec3b
 MatVec3b MatVec3b_New() {
     return new cv::Mat_<cv::Vec3b>();

core.go

@@ -37,6 +37,12 @@ func (m *Mat) Delete() {
 	m.p = nil
 }
 
+// Empty determines if the Mat is empty or not.
+func (m *Mat) Empty() bool {
+	isEmpty := C.Mat_Empty(m.p)
+	return isEmpty != 0
+}
+
 // CMatVec3b is an alias for C pointer.
 type CMatVec3b C.MatVec3b
 

core.h

@@ -41,6 +41,7 @@ typedef struct RawData {
 
   Mat Mat_New();
   void Mat_Delete(Mat m);
+  int Mat_Empty(Mat m);
 
   MatVec3b MatVec3b_New();
   struct ByteArray MatVec3b_ToJpegData(MatVec3b m, int quality);

examples/capture.go

@@ -16,7 +16,7 @@ func main() {
 	}
 
 	// streaming, capture from webcam
-	buf := opencv3.NewMatVec3b()
+	buf := opencv3.NewMat()
 	defer buf.Delete()
 	fmt.Printf("start reading camera device: %v\n", deviceID)
 	for {

examples/capwindow.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"fmt"
+
+	opencv3 ".."
+)
+
+func main() {
+	deviceID := 0
+	webcam := opencv3.NewVideoCapture()
+	defer webcam.Delete()
+
+	if ok := webcam.OpenDevice(int(deviceID)); !ok {
+		fmt.Printf("error opening device: %v\n", deviceID)
+		return
+	}
+
+	window := opencv3.NewWindow("Capture")
+
+	// streaming, capture from webcam
+	img := opencv3.NewMat()
+	defer img.Delete()
+	fmt.Printf("start reading camera device: %v\n", deviceID)
+	for {
+		if ok := webcam.Read(img); !ok {
+			fmt.Printf("cannot read device %d\n", deviceID)
+			return
+		}
+		if img.Empty() {
+			continue
+		}
+
+		window.IMShow(img)
+		opencv3.WaitKey(1)
+	}
+}

videoio.cpp

@@ -29,7 +29,7 @@ int VideoCapture_IsOpened(VideoCapture v) {
     return v->isOpened();
 }
 
-int VideoCapture_Read(VideoCapture v, MatVec3b buf) {
+int VideoCapture_Read(VideoCapture v, Mat buf) {
     return v->read(*buf);
 }
 

videoio.go

@@ -54,9 +54,9 @@ func (v *VideoCapture) IsOpened() bool {
 	return isOpened != 0
 }
 
-// Read set frame to argument MatVec3b, returns `false` when the video capture
+// Read set frame to argument Mat, returns `false` when the video capture
 // cannot read frame.
-func (v *VideoCapture) Read(m MatVec3b) bool {
+func (v *VideoCapture) Read(m Mat) bool {
 	return C.VideoCapture_Read(v.p, m.p) != 0
 }
 

videoio.h

@@ -24,7 +24,7 @@ int VideoCapture_OpenDevice(VideoCapture v, int device);
 void VideoCapture_Release(VideoCapture v);
 void VideoCapture_Set(VideoCapture v, int prop, int param);
 int VideoCapture_IsOpened(VideoCapture v);
-int VideoCapture_Read(VideoCapture v, MatVec3b buf);
+int VideoCapture_Read(VideoCapture v, Mat buf);
 void VideoCapture_Grab(VideoCapture v, int skip);
 
 // VideoWriter