Image To CVPixelBuffer in Swift

imageToPixelBuffer.swift

var thePixelBuffer : CVPixelBuffer?

let testImage : UIImage = UIImage.init(named: "twdEnds.png")!
self.thePixelBuffer = self.pixelBufferFromImage(image: testImage)




func pixelBufferFromImage(image: UIImage) -> CVPixelBuffer {
        
        
        let ciimage = CIImage(image: image)
        //let cgimage = convertCIImageToCGImage(inputImage: ciimage!)
        let tmpcontext = CIContext(options: nil)
        let cgimage =  tmpcontext.createCGImage(ciimage!, from: ciimage!.extent)
        
        let cfnumPointer = UnsafeMutablePointer<UnsafeRawPointer>.allocate(capacity: 1)
        let cfnum = CFNumberCreate(kCFAllocatorDefault, .intType, cfnumPointer)
        let keys: [CFString] = [kCVPixelBufferCGImageCompatibilityKey, kCVPixelBufferCGBitmapContextCompatibilityKey, kCVPixelBufferBytesPerRowAlignmentKey]
        let values: [CFTypeRef] = [kCFBooleanTrue, kCFBooleanTrue, cfnum!]
        let keysPointer = UnsafeMutablePointer<UnsafeRawPointer?>.allocate(capacity: 1)
        let valuesPointer =  UnsafeMutablePointer<UnsafeRawPointer?>.allocate(capacity: 1)
        keysPointer.initialize(to: keys)
        valuesPointer.initialize(to: values)
        
        let options = CFDictionaryCreate(kCFAllocatorDefault, keysPointer, valuesPointer, keys.count, nil, nil)
       
        let width = cgimage!.width
        let height = cgimage!.height
     
        var pxbuffer: CVPixelBuffer?
        // if pxbuffer = nil, you will get status = -6661
        var status = CVPixelBufferCreate(kCFAllocatorDefault, width, height,
                                         kCVPixelFormatType_32BGRA, options, &pxbuffer)
        status = CVPixelBufferLockBaseAddress(pxbuffer!, CVPixelBufferLockFlags(rawValue: 0));
        
        let bufferAddress = CVPixelBufferGetBaseAddress(pxbuffer!);

        
        let rgbColorSpace = CGColorSpaceCreateDeviceRGB();
        let bytesperrow = CVPixelBufferGetBytesPerRow(pxbuffer!)
        let context = CGContext(data: bufferAddress,
                                width: width,
                                height: height,
                                bitsPerComponent: 8,
                                bytesPerRow: bytesperrow,
                                space: rgbColorSpace,
                                bitmapInfo: CGImageAlphaInfo.premultipliedFirst.rawValue | CGBitmapInfo.byteOrder32Little.rawValue);
        context?.concatenate(CGAffineTransform(rotationAngle: 0))
        context?.concatenate(__CGAffineTransformMake( 1, 0, 0, -1, 0, CGFloat(height) )) //Flip Vertical
//        context?.concatenate(__CGAffineTransformMake( -1.0, 0.0, 0.0, 1.0, CGFloat(width), 0.0)) //Flip Horizontal
        

        context?.draw(cgimage!, in: CGRect(x:0, y:0, width:CGFloat(width), height:CGFloat(height)));
        status = CVPixelBufferUnlockBaseAddress(pxbuffer!, CVPixelBufferLockFlags(rawValue: 0));
        return pxbuffer!;
        
    }

Note:
if you are using this buffer to do some Metal work then add kCVPixelBufferMetalCompatibilityKey: kCFBooleanTrue to attrs.