>> On Dec 5, 2012, at 19:53 , gary.gard...@brokensoftware.com wrote: >> >>> Do I need to use CoreMedia to actually get an image from the >>> sampleBuffer? >>> Using Xcode, it appears that UIImage is for iOS (this is just a >>> supposition). So XCode changes the code to CIImage. >>> >>> If this is the wrong direction, please point me in the right direction. >>> >>> The AVFoundation examples seem to all be based on IOS and not MAC for >>> the >>> Media Steaming. Therefore those examples don't work for what I am >>> trying >>> to do. >> >> You're correct that the Mac version of the docs haven't been changed >> from >> the iOS version, but luckily there is (I think) very little difference >> you >> need to take into account. >> >> Assuming you have by now got your data capture delegate set up properly, >> you need to have it do the equivalent of this: >> >> >> https://developer.apple.com/library/mac/#documentation/AudioVideo/Conceptual/AVFoundationPG/Articles/05_MediaRepresentations.html >> >> under the final heading "Converting a CMSampleBuffer to a UIImage". In >> that sample code, you should only have to change one line from its iOS >> version: >> >> UIImage *image = [UIImage imageWithCGImage:cgImage]; >> >> to the corresponding Mac version: >> >> NSImage *image = [NSImage imageWithCGImage:cgImage]; >> >> What happens next depends on what you want to do with the image. If you >> want to display it, you can simply draw this NSImage object. If you want >> to write each frame to a separate file, you could use a NSImage method >> to >> get the TIFF representation as a NSData object and write that out. If >> you >> need to convert the image to a specific form, you will likely have to >> start creating NSImageRep objects (or a subclass like NSBitmapImageRep), >> but the details will depend on where you're trying to get to. >> >> Note that in some scenarios, you could choose to work with the cgImage >> directly, rather than creating a NSImage (which is, loosely, just going >> to >> function as a wrapper around the CGImage, at least to begin with). The >> advantage of using NSImage is that it's often less lines of code to use >> than CGImage (and it's an Objective-C rather than a C API). >> >> P.S. The intermediary code uses CVPixelBuffer and CGImage objects, not >> CIImage objects. CIImage objects are something else entirely -- they're >> image containers to which image filters can be applied -- that is, >> they're >> essentially image transformations. If, for example, you wanted to apply >> a >> Gaussian blur to every frame, you could use CIImage objects to do this. > > > The changes I had to make are as follows: > > Using CIImage: > CIImage *image = [CIImage imageWithCGImage:quartzImage]; > > Using NSImage: > NSImage *image = [[NSImage alloc] initWithCGImage:cgImage > size:NSZeroSize]; > > With the NSImage, I was getting an additional Error message that I had to > trap for, but not with the CIImage. > > > > _______________________________________________ > > 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: > https://lists.apple.com/mailman/options/cocoa-dev/gary.gardner%40brokensoftware.com > > This email sent to gary.gard...@brokensoftware.com >
I need further assistance. I select the capture device, but after I execute run, I get the following: Invalid memory access of location 0x0 rip=0x7fff933e3598 942 Segmentation fault: 11 I am following the AVVideoWall example code. However, I am not outputting to the desktop and layers. Can someone point me in the right direction on solving this issue? Thanks. _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
