iOS CMSampleBuffer deep copy

extension CVPixelBuffer {
    func copy() -> CVPixelBuffer {
        precondition(CFGetTypeID(self) == CVPixelBufferGetTypeID(), "copy() cannot be called on a non-CVPixelBuffer")

        var _copy : CVPixelBuffer?

//        var BytesAlignment:Int = 4
//        let CFBytesAlignment = CFNumberCreate(kCFAllocatorDefault, .intType, &BytesAlignment)!
        let attribute:[String:Any] = [kCVPixelBufferMetalCompatibilityKey as String:kCFBooleanTrue]
//                                      kCVPixelBufferBytesPerRowAlignmentKey as String:CFBytesAlignment

        CVPixelBufferCreate(
            kCFAllocatorDefault,
            CVPixelBufferGetWidth(self),
            CVPixelBufferGetHeight(self),
            CVPixelBufferGetPixelFormatType(self),
            attribute as CFDictionary,
            &_copy)

        guard let copy = _copy else { fatalError() }

        CVPixelBufferLockBaseAddress(self, CVPixelBufferLockFlags.readOnly)
        CVPixelBufferLockBaseAddress(copy, CVPixelBufferLockFlags(rawValue: ))

        for plane in ..<CVPixelBufferGetPlaneCount(self) {
            let dest = CVPixelBufferGetBaseAddressOfPlane(copy, plane)
            let source = CVPixelBufferGetBaseAddressOfPlane(self, plane)
            let height = CVPixelBufferGetHeightOfPlane(self, plane)
            let bytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(self, plane)

            let bytesPerRowDst = CVPixelBufferGetBytesPerRowOfPlane(copy, plane)

            for h in ..<height {
                memcpy(dest?.advanced(by:h*bytesPerRowDst), source?.advanced(by:h*bytesPerRow),  bytesPerRow)
            }
        }

        CVPixelBufferUnlockBaseAddress(copy, CVPixelBufferLockFlags(rawValue: ))
        CVPixelBufferUnlockBaseAddress(self, CVPixelBufferLockFlags.readOnly)

        return copy
    }
}

https://stackoverflow.com/questions/38335365/pulling-data-from-a-cmsamplebuffer-in-order-to-create-a-deep-copy

http://blog.csdn.net/fernandowei/article/details/52180840