kCVReturnAllocationFailed
kCVReturnDisplayLinkAlreadyRunning
kCVReturnDisplayLinkCallbacksNotSet
kCVReturnDisplayLinkNotRunning
kCVReturnError
kCVReturnFirst
kCVReturnInvalidArgument
kCVReturnInvalidDisplay
kCVReturnInvalidPixelBufferAttributes
kCVReturnInvalidPixelFormat
kCVReturnInvalidPoolAttributes
kCVReturnInvalidSize
kCVReturnLast
kCVReturnPixelBufferNotOpenGLCompatible
kCVReturnPoolAllocationFailed
kCVReturnSuccess
kCVReturnWouldExceedAllocationThreshold