vImageCVImageFormat_GetConversionMatrix(_:_:)
Returns a pointer to the RGB-to-YpCbCr conversion matrix of a Core Video image format.
Declaration
func vImageCVImageFormat_GetConversionMatrix(_ format: vImageConstCVImageFormat, _ outType: UnsafeMutablePointer<vImageMatrixType>!) -> UnsafeRawPointer!Parameters
- format:
The Core Video image format to query.
- outType:
A pointer to a
vImageMatrixType.
Return Value
A pointer to the conversion matrix.
Discussion
The functions that create Core Video image formats, such as vImageCVImageFormat_CreateWithCVPixelBuffer(_:), return a vImageCVImageFormat. The following code shows how you create a vImageConstCVImageFormat representation of a vImageCVImageFormat instance to pass to vImageCVImageFormat_GetConversionMatrix(_:_:):
let conversionMatrixPointer = withUnsafeBytes(of: cvImageFormat) { bytes in
var outType = UInt32()
let format = bytes.assumingMemoryBound(
to: vImageConstCVImageFormat.self).first!
return vImageCVImageFormat_GetConversionMatrix(format, &outType)
}