78 lines
2.0 KiB
C++
78 lines
2.0 KiB
C++
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#include "DispmanxFrameGrabber.h"
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DispmanxFrameGrabber::DispmanxFrameGrabber(const unsigned width, const unsigned height) :
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_vc_display(0),
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_vc_resource(0),
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_vc_flags(0),
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_width(width),
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_height(height)
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{
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// Initiase BCM
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bcm_host_init();
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{
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// Check if the display can be opened and display the current resolution
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// Open the connection to the display
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_vc_display = vc_dispmanx_display_open(0);
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assert(_vc_display > 0);
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// Obtain the display information
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DISPMANX_MODEINFO_T vc_info;
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int result = vc_dispmanx_display_get_info(_vc_display, &vc_info);
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// Keep compiler happy in 'release' mode
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(void)result;
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assert(result == 0);
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std::cout << "Display opened with resolution: " << vc_info.width << "x" << vc_info.height << std::endl;
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// Close the displaye
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vc_dispmanx_display_close(_vc_display);
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}
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// Create the resources for capturing image
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uint32_t vc_nativeImageHandle;
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_vc_resource = vc_dispmanx_resource_create(
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VC_IMAGE_RGB888,
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width,
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height,
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&vc_nativeImageHandle);
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assert(_vc_resource);
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// Define the capture rectangle with the same size
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vc_dispmanx_rect_set(&_rectangle, 0, 0, width, height);
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}
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DispmanxFrameGrabber::~DispmanxFrameGrabber()
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{
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// Clean up resources
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vc_dispmanx_resource_delete(_vc_resource);
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// De-init BCM
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bcm_host_deinit();
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}
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void DispmanxFrameGrabber::setFlags(const int vc_flags)
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{
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_vc_flags = vc_flags;
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}
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void DispmanxFrameGrabber::grabFrame(RgbImage& image)
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{
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// Sanity check of the given image size
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assert(image.width() == _width && image.height() == _height);
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// Open the connection to the display
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_vc_display = vc_dispmanx_display_open(0);
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// Create the snapshot (incl down-scaling)
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vc_dispmanx_snapshot(_vc_display, _vc_resource, (DISPMANX_TRANSFORM_T) _vc_flags);
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// Read the snapshot into the memory
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void* image_ptr = image.memptr();
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const unsigned destPitch = _width * 3;
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vc_dispmanx_resource_read_data(_vc_resource, &_rectangle, image_ptr, destPitch);
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// Close the displaye
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vc_dispmanx_display_close(_vc_display);
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}
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