camera-with-effects.m

- (void)setupCamera
{
    self.coreImageContext = [CIContext contextWithOptions:nil];

    // session
    self.cameraSession = [[AVCaptureSession alloc] init];
    [self.cameraSession setSessionPreset:AVCaptureSessionPresetPhoto];
    [self.cameraSession commitConfiguration];
    
    // input
    AVCaptureDevice *shootingCamera = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    AVCaptureDeviceInput *shootingDevice = [AVCaptureDeviceInput deviceInputWithDevice:shootingCamera error:NULL];
    if ([self.cameraSession canAddInput:shootingDevice]) {
        [self.cameraSession addInput:shootingDevice];
    }
    
    // video output
    self.videoOutput = [[AVCaptureVideoDataOutput alloc] init];
    self.videoOutput.alwaysDiscardsLateVideoFrames = YES;
    [self.videoOutput setSampleBufferDelegate:self queue:dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0)];
    if ([self.cameraSession canAddOutput:self.videoOutput]) {
        [self.cameraSession addOutput:self.videoOutput];
    }

    if (self.videoOutput.connections.count > 0) {
        AVCaptureConnection *connection = self.videoOutput.connections[0];
        connection.videoOrientation = AVCaptureVideoOrientationPortrait;
    }
    
    self.cameraOpen = NO;
}

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection
{
    // Get a CMSampleBuffer's Core Video image buffer for the media data
    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    
    // turn buffer into an image we can manipulate
    CIImage *result = [CIImage imageWithCVPixelBuffer:imageBuffer];

    CIFilter *grayscaleFilter = [CIFilter filterWithName:@"CIColorMonochrome"];
    [grayscaleFilter setDefaults];
    [grayscaleFilter setValue:result forKey:@"inputImage"];
    [grayscaleFilter setValue:[CIColor colorWithRed:.6f green:.6f blue:.6f alpha:1.f] forKey:@"inputColor"];
    result = grayscaleFilter.outputImage;
    
    // filter
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
    [filter setDefaults];
    [filter setValue:result forKey:@"inputImage"];
    
    CGFloat inputRadius = 10.0f;
    [filter setValue:@(inputRadius) forKey:@"inputRadius"];

    CGRect rect = result.extent;
    rect.origin.x += inputRadius;
    rect.origin.y += inputRadius;
    rect.size.width -= 2 * inputRadius;
    rect.size.height -= 2 * inputRadius;
    
    CGRect originalRect = rect;
    originalRect.origin.x += 80;
    originalRect.origin.y += 80;
    originalRect.size.width -= 160;
    originalRect.size.height -= 160;
    
    // render image
    CGImageRef blurredImage = [self.coreImageContext createCGImage:filter.outputImage fromRect:rect];
    CGImageRef originalImage = [self.coreImageContext createCGImage:result fromRect:originalRect];
    dispatch_async(dispatch_get_main_queue(), ^{
        self.cameraView.layer.contentsGravity = @"resizeAspectFill";
        self.cameraView.layer.contents = (__bridge id)originalImage;
        self.blurCameraView.layer.contents = (__bridge id)blurredImage;
        CGImageRelease(originalImage);
        CGImageRelease(blurredImage);
    });
}

- (void)openCamera
{
    if (self.cameraOpen) {
        return;
    }
    
    self.cameraView.alpha = 0.0f;
    self.blurCameraView.alpha = 0.0f;
    self.viewfinderMaskImageView.alpha = 1.0f;
    self.shutterView.alpha = 0.0f;
    [self.cameraSession startRunning];
    [self.view layoutIfNeeded];

    [UIView animateWithDuration:3.0f animations:^{
        self.cameraView.alpha = 1.0f;
        self.blurCameraView.alpha = 1.0f;
        self.viewfinderMaskImageView.alpha = 0.60f;
    }];
    
    [UIView animateWithDuration:0.2f delay:2.8f options:0 animations:^{
        [self showShootButton];
    } completion:nil];
    
    self.cameraOpen = YES;
}

- (void)closeCamera
{
    if (!self.cameraOpen) {
        return; // camera is closed
    }
    
    [UIView animateWithDuration:0.5f animations:^{
        self.cameraView.alpha = 0.0f;
        self.blurCameraView.alpha = 0.0f;
        self.viewfinderMaskImageView.alpha = 1.0f;
        self.shutterView.alpha = 0.0f;
    } completion:^(BOOL finished) {
        [self.cameraSession stopRunning];
    }];
    
    [UIView animateWithDuration:0.2f delay:0.0f options:0 animations:^{
        [self hideShootButton];
    } completion:nil];
    
    self.cameraOpen = NO;
}