> 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/archive%40mail-archive.com This email sent to arch...@mail-archive.com
