Move V4L2 grabber code to separate library

Former-commit-id: f3003eb0142af3d085ccf93fff1b297ebc2321fc

libsrc/grabber/dispmanx/DispmanxFrameGrabber.cpp

@@ -0,0 +1,101 @@
+
+// STL includes
+#include <cassert>
+#include <iostream>
+
+// Local includes
+#include "DispmanxFrameGrabber.h"
+
+DispmanxFrameGrabber::DispmanxFrameGrabber(const unsigned width, const unsigned height) :
+	_vc_display(0),
+	_vc_resource(0),
+	_vc_flags(0),
+	_width(width),
+	_height(height)
+{
+	// Initiase BCM
+	bcm_host_init();
+
+	{
+		// Check if the display can be opened and display the current resolution
+		// Open the connection to the display
+		_vc_display = vc_dispmanx_display_open(0);
+		assert(_vc_display > 0);
+
+		// Obtain the display information
+		DISPMANX_MODEINFO_T vc_info;
+		int result = vc_dispmanx_display_get_info(_vc_display, &vc_info);
+		// Keep compiler happy in 'release' mode
+		(void)result;
+		assert(result == 0);
+		std::cout << "Display opened with resolution: " << vc_info.width << "x" << vc_info.height << std::endl;
+
+		// Close the displaye
+		vc_dispmanx_display_close(_vc_display);
+	}
+
+	// Create the resources for capturing image
+	uint32_t vc_nativeImageHandle;
+	_vc_resource = vc_dispmanx_resource_create(
+			VC_IMAGE_RGBA32,
+			width,
+			height,
+			&vc_nativeImageHandle);
+	assert(_vc_resource);
+
+	// Define the capture rectangle with the same size
+	vc_dispmanx_rect_set(&_rectangle, 0, 0, width, height);
+}
+
+DispmanxFrameGrabber::~DispmanxFrameGrabber()
+{
+	// Clean up resources
+	vc_dispmanx_resource_delete(_vc_resource);
+
+	// De-init BCM
+	bcm_host_deinit();
+}
+
+void DispmanxFrameGrabber::setFlags(const int vc_flags)
+{
+	_vc_flags = vc_flags;
+}
+
+void DispmanxFrameGrabber::setVideoMode(const VideoMode videoMode)
+{
+	switch (videoMode) {
+	case VIDEO_3DSBS:
+		vc_dispmanx_rect_set(&_rectangle, 0, 0, _width/2, _height);
+		break;
+	case VIDEO_3DTAB:
+		vc_dispmanx_rect_set(&_rectangle, 0, 0, _width, _height/2);
+		break;
+	case VIDEO_2D:
+	default:
+		vc_dispmanx_rect_set(&_rectangle, 0, 0, _width, _height);
+		break;
+	}
+}
+
+void DispmanxFrameGrabber::grabFrame(Image<ColorRgba> & image)
+{
+	// resize the given image if needed
+	if (image.width() != unsigned(_rectangle.width) || image.height() != unsigned(_rectangle.height))
+	{
+		image.resize(_rectangle.width, _rectangle.height);
+	}
+
+	// Open the connection to the display
+	_vc_display = vc_dispmanx_display_open(0);
+
+	// Create the snapshot (incl down-scaling)
+	vc_dispmanx_snapshot(_vc_display, _vc_resource, (DISPMANX_TRANSFORM_T) _vc_flags);
+
+	// Read the snapshot into the memory
+	void* image_ptr = image.memptr();
+	const unsigned destPitch = _rectangle.width * sizeof(ColorRgba);
+	vc_dispmanx_resource_read_data(_vc_resource, &_rectangle, image_ptr, destPitch);
+
+	// Close the displaye
+	vc_dispmanx_display_close(_vc_display);
+}