FD

FD.m

- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
       fromConnection:(AVCaptureConnection *)connection {
    CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    CFDictionaryRef attachments = CMCopyDictionaryOfAttachments(kCFAllocatorDefault, sampleBuffer, kCMAttachmentMode_ShouldPropagate);
    CIImage *ciImage = [[CIImage alloc] initWithCVPixelBuffer:pixelBuffer
                                                      options:(__bridge NSDictionary *)attachments];
    if (attachments) {
        CFRelease(attachments);
    }
    
    // make sure your device orientation is not locked.
    UIDeviceOrientation curDeviceOrientation = [[UIDevice currentDevice] orientation];

    NSDictionary *imageOptions = nil;

    imageOptions = [NSDictionary dictionaryWithObject:[self exifOrientation:curDeviceOrientation]
                                               forKey:CIDetectorImageOrientation];

    NSArray *features = [self._faceDetector featuresInImage:ciImage
                                                    options:imageOptions];

    CMFormatDescriptionRef fdesc = CMSampleBufferGetFormatDescription(sampleBuffer);
    CGRect cleanAperture = CMVideoFormatDescriptionGetCleanAperture(fdesc, false /*originIsTopLeft == false*/);
    
    dispatch_async(dispatch_get_main_queue(), ^(void) {
        [self drawFaces:features
            forVideoBox:cleanAperture
            orientation:curDeviceOrientation];
    });
}