hyperion.ng/libsrc/hyperion/DispmanxFrameGrabber.cpp

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#include "DispmanxFrameGrabber.h"
DispmanxFrameGrabber::DispmanxFrameGrabber(const unsigned width, const unsigned height) :
_display(0),
_resource(0),
_width(width),
_height(height)
{
// Initiase BCM
bcm_host_init();
// Open the connection to the display
_display = vc_dispmanx_display_open(0);
int ret = vc_dispmanx_display_get_info(_display, &_info);
// Make the compiler (in release mode) happy by 'using' ret
(void)ret;
assert(ret == 0);
// Create the resources for capturing image
_resource = vc_dispmanx_resource_create(
VC_IMAGE_RGB888,
width,
height,
&_vc_image_ptr);
assert(_resource);
// Define the capture rectangle with the same size
vc_dispmanx_rect_set(&_rectangle, 0, 0, width, height);
_pitch = width * 3;
}
DispmanxFrameGrabber::~DispmanxFrameGrabber()
{
// Clean up resources
vc_dispmanx_resource_delete(_resource);
// Close the displaye
vc_dispmanx_display_close(_display);
// De-init BCM
bcm_host_deinit();
}
void DispmanxFrameGrabber::grabFrame(RgbImage& image)
{
// Sanity check of the given image size
assert(image.width() == _width && image.height() == _height);
void* image_ptr = image.memptr();
// Create the snapshot
vc_dispmanx_snapshot(_display, _resource, VC_IMAGE_ROT0);
// Read the snapshot into the memory (incl down-scaling)
vc_dispmanx_resource_read_data(_resource, &_rectangle, image_ptr, _pitch);
}