Hi again, 1 jan 2010 kl. 13.13 skrev Mike Abdullah:
> QTCaptureView is almost certainly internally using something along the lines > of OpenGL internally to draw onscreen with acceptable performance. This means > you can't draw on top of it with standard Cocoa drawing techniques. The > options: > > A) Use an overlay window I tried it starting from the "Movie Overlay" sample code and it might work. However, copying this solution directly from the sample code adds a haze over my video. How can I avoid this? > > B) Implement the -view:willDisplayImage: delegate method and return a new > image that will draw with the crosshairs This would require that I go from a CIImage to a NSImage, draw into it, and back again to CIImage. True? Will it affect fps performance? > > C) Place the capture view in a layer-backed view hierarchy and add an overlay > view – I don't know if QTCaptureView supports being layer-backed, or if an > overlay view will then work. > D) Switch to QTCaptureLayer. Add an overlay layer for the crosshairs. I really did try to google for sample code on QTCaptureLayer, but I found none. Any links on this would be appreciated. > > On 31 Dec 2009, at 16:14, Bengt Nilsson wrote: > >> I need to draw a cross-hair on top of a QTCaptureView with a video preview >> from a USB camera. >> For this app, I am starting from the sample project QTRecorder. >> I create the cross-hair line in the Interface Builder. >> Problem is that the video is always on top, overwriting the cross-hair lines. >> Is there a way to let the cross-hair lines be drawn in front of the video, >> by some property setting in IB for the lines? >> I tried different settings, like "move to front", defining "parent", etc., >> but nothing seems to help. >> Or do they need to be drawn programatically? >> >> BN >> >> _______________________________________________ >> >> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) >> >> Please do not post admin requests or moderator comments to the list. >> Contact the moderators at cocoa-dev-admins(at)lists.apple.com >> >> Help/Unsubscribe/Update your Subscription: >> http://lists.apple.com/mailman/options/cocoa-dev/cocoadev%40mikeabdullah.net >> >> This email sent to cocoa...@mikeabdullah.net > _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
