hyperion.ng/libsrc/grabber/osx/OsxFrameGrabber.cpp

// STL includes
#include <cassert>
#include <iostream>

// Local includes
#include <grabber/OsxFrameGrabber.h>

OsxFrameGrabber::OsxFrameGrabber(const unsigned display, const unsigned width, const unsigned height)
	: Grabber("OSXGRABBER", width, height)
	, _screenIndex(100)
{
	// check if display is available
	setDisplayIndex(display);
}

OsxFrameGrabber::~OsxFrameGrabber()
{
}

int OsxFrameGrabber::grabFrame(Image<ColorRgb> & image)
{
	if (!_enabled) return 0;

	CGImageRef dispImage;
	CFDataRef imgData;
	unsigned char * pImgData;
	unsigned dspWidth, dspHeight;

	dispImage = CGDisplayCreateImage(_display);

	// display lost, use main
	if (dispImage == NULL && _display)
	{
		dispImage = CGDisplayCreateImage(kCGDirectMainDisplay);
		// no displays connected, return
		if (dispImage == NULL)
		{
			Error(_log, "No display connected...");
			return -1;
		}
	}
	imgData   = CGDataProviderCopyData(CGImageGetDataProvider(dispImage));
	pImgData  = (unsigned char*) CFDataGetBytePtr(imgData);
	dspWidth  = CGImageGetWidth(dispImage);
	dspHeight = CGImageGetHeight(dispImage);

	_imageResampler.setHorizontalPixelDecimation(dspWidth/_width);
	_imageResampler.setVerticalPixelDecimation(dspHeight/_height);
	_imageResampler.processImage( pImgData,
								dspWidth,
								dspHeight,
								CGImageGetBytesPerRow(dispImage),
								PixelFormat::BGR32,
								image);

	CFRelease(imgData);
	CGImageRelease(dispImage);

	return 0;
}

void OsxFrameGrabber::setDisplayIndex(int index)
{
	if(_screenIndex != index)
	{
		_screenIndex = index;

		CGImageRef image;
		CGDisplayCount displayCount;
		CGDirectDisplayID displays[8];

		// get list of displays
		CGGetActiveDisplayList(8, displays, &displayCount);
		if (_screenIndex + 1 > displayCount)
		{
			Error(_log, "Display with index %d is not available. Using main display", _screenIndex);
			_display = kCGDirectMainDisplay;
		}
		else
		{
			_display = displays[_screenIndex];
		}

		image = CGDisplayCreateImage(_display);
		if(image == NULL)
		{
			Error(_log, "Failed to open main display, disable capture interface");
			setEnabled(false);
			return;
		}
		else
			setEnabled(true);

		Info(_log, "Display opened with resolution: %dx%d@%dbit", CGImageGetWidth(image), CGImageGetHeight(image), CGImageGetBitsPerPixel(image));

		CGImageRelease(image);
	}
}