Updated the snapshot creation based on the latest release of VideoCore (included backwards compatibility if correct)

Former-commit-id: 5bb8d6d7cd673ac8c08a2c9a8f1995231074d327

include/dispmanx-grabber/DispmanxWrapper.h

@@ -55,10 +55,10 @@ public slots:
 	void stop();
 
 	///
-	/// \brief Set the grabbing mode
-	/// \param mode The new grabbing mode
+	/// Set the grabbing mode
+	/// @param[in] mode The new grabbing mode
 	///
-	void setGrabbingMode(GrabbingMode mode);
+	void setGrabbingMode(const GrabbingMode mode);
 
 private:
 	/// The update rate [Hz]

include/utils/GrabbingMode.h

@@ -1,8 +1,13 @@
 #pragma once
 
+/**
+ * Enumeration of the possible modes in which frame-grabbing is performed.
+ */
 enum GrabbingMode
 {
+	/** Frame grabbing is switched off */
 	GRABBINGMODE_OFF,
+	/** Frame grabbing during video */
 	GRABBINGMODE_VIDEO,
 	GRABBINGMODE_PHOTO,
 	GRABBINGMODE_AUDIO,

libsrc/dispmanx-grabber/DispmanxFrameGrabber.cpp

@@ -1,9 +1,22 @@
 
 #include "DispmanxFrameGrabber.h"
 
+// Because the shapshot function is incompatible between versions (use of different enum as
+// third argument) and no proper version number is available as preprocessor define we cast the
+// function to the same function with the third argument as 'int'.
+// This way we can call the function in both versions of the VideoCore library without
+// switching.
+static int my_vc_dispmanx_snapshot(DISPMANX_DISPLAY_HANDLE_T display, DISPMANX_RESOURCE_HANDLE_T snapshot_resource, int transform)
+{
+	typedef int (*SnapshotFunctionPtr)(DISPMANX_DISPLAY_HANDLE_T, DISPMANX_RESOURCE_HANDLE_T, int);
+	SnapshotFunctionPtr snapshot = (SnapshotFunctionPtr) &vc_dispmanx_snapshot;
+	return (*snapshot)(display, snapshot_resource, transform);
+}
+
 DispmanxFrameGrabber::DispmanxFrameGrabber(const unsigned width, const unsigned height) :
 	_vc_display(0),
 	_vc_resource(0),
+	_vc_flags(0),
 	_width(width),
 	_height(height)
 {
@@ -50,6 +63,11 @@ DispmanxFrameGrabber::~DispmanxFrameGrabber()
 	bcm_host_deinit();
 }
 
+void DispmanxFrameGrabber::setFlags(const int vc_flags)
+{
+	_vc_flags = vc_flags;
+}
+
 void DispmanxFrameGrabber::grabFrame(RgbImage& image)
 {
 	// Sanity check of the given image size
@@ -59,7 +77,7 @@ void DispmanxFrameGrabber::grabFrame(RgbImage& image)
 	_vc_display = vc_dispmanx_display_open(0);
 
 	// Create the snapshot (incl down-scaling)
-	vc_dispmanx_snapshot(_vc_display, _vc_resource, VC_IMAGE_ROT0);
+	my_vc_dispmanx_snapshot(_vc_display, _vc_resource, _vc_flags);
 
 	// Read the snapshot into the memory
 	void* image_ptr = image.memptr();

libsrc/dispmanx-grabber/DispmanxFrameGrabber.h

@@ -26,6 +26,13 @@ public:
 	DispmanxFrameGrabber(const unsigned width, const unsigned height);
 	~DispmanxFrameGrabber();
 
+	///
+	/// Updates the frame-grab flags as used by the VC library for frame grabbing
+	///
+	/// @param vc_flags  The snapshot grabbing mask
+	///
+	void setFlags(const int vc_flags);
+
 	///
 	/// Captures a single snapshot of the display and writes the data to the given image. The
 	/// provided image should have the same dimensions as the configured values (_width and
@@ -46,8 +53,12 @@ private:
 	/// Rectangle of the captured resource that is transfered to user space
 	VC_RECT_T _rectangle;
 
+	/// Flags (transforms) for creating snapshots
+	int _vc_flags;
+
 	/// With of the captured snapshot [pixels]
 	unsigned _width;
 	/// Height of the captured snapshot [pixels]
 	unsigned _height;
+
 };

libsrc/dispmanx-grabber/DispmanxWrapper.cpp

@@ -61,10 +61,23 @@ void DispmanxWrapper::stop()
 	_timer.stop();
 }
 
-void DispmanxWrapper::setGrabbingMode(GrabbingMode mode)
+void DispmanxWrapper::setGrabbingMode(const GrabbingMode mode)
 {
-	if (mode == GRABBINGMODE_VIDEO)
+	switch (mode)
+	{
+	case GRABBINGMODE_VIDEO:
+		_frameGrabber->setFlags(DISPMANX_SNAPSHOT_NO_RGB|DISPMANX_SNAPSHOT_FILL);
 		start();
-	else
+	case GRABBINGMODE_AUDIO:
+	case GRABBINGMODE_PHOTO:
+	case GRABBINGMODE_MENU:
+		_frameGrabber->setFlags(0);
+		start();
+		break;
+	case GRABBINGMODE_OFF:
 		stop();
+		break;
+	case GRABBINGMODE_INVALID:
+		break;
+	}
 }