Flipping Quicktime preview & capture - objective-c

Question

I need to horizontally flip some video I'm previewing and capturing. A-la iChat, I have a webcam and want it to appear as though the user is looking in a mirror.
I'm previewing Quicktime video in a QTCaptureView. My capturing is done frame-by-frame (for reasons I won't get into) with something like:
imageRep = [NSCIImageRep imageRepWithCIImage: [CIImage imageWithCVImageBuffer: frame]];
image = [[NSImage alloc] initWithSize: [imageRep size]];
[image addRepresentation: imageRep];
[movie addImage: image forDuration: someDuration withAttributes: someAttributes];
Any tips?

Answer 1

Nothing like resurrecting an old question. Anyway I came here and almost found what I was looking for thanks to Brian Webster but if anyone is looking for the wholesale solution try this after setting your class as the delegate of the QTCaptureView instance:
- (CIImage *)view:(QTCaptureView *)view willDisplayImage:(CIImage *)image {
//mirror image across y axis
return [image imageByApplyingTransform:CGAffineTransformMakeScale(-1, 1)];
}

Answer 2

You could do this by taking the CIImage you're getting from the capture and running it through a Core Image filter to flip the image around. You would then pass the resulting image into your image rep rather than the original one. The code would look something like:
CIImage* capturedImage = [CIImage imageWithCVImageBuffer:buffer];
NSAffineTransform* flipTransform = [NSAffineTransform transform];
CIFilter* flipFilter;
CIImage* flippedImage;
[flipTransform scaleByX:-1.0 y:1.0]; //horizontal flip
flipFilter = [CIImage filterWithName:#"CIAffineTransform"];
[flipFilter setValue:flipTransform forKey:#"inputTransform"];
[flipFilter setValue:capturedImage forKey:#"inputImage"];
flippedImage = [flipFilter valueForKey:#"outputImage"];
imageRep = [NSCIImageRep imageRepWithCIImage:flippedImage];
...

Answer 3

Try this!
it will apply filters to CaptureView, but not to the output video.
- (IBAction)Vibrance:(id)sender
{
CIFilter* CIVibrance = [CIFilter filterWithName:#"CIVibrance" keysAndValues:
#"inputAmount", [NSNumber numberWithDouble:2.0f],
nil];
mCaptureView.contentFilters = [NSArray arrayWithObject:CIVibrance];
}
btw, you can apply any filters from this ref: https://developer.apple.com/library/mac/#documentation/graphicsimaging/reference/CoreImageFilterReference/Reference/reference.html