Creates a data structure for use with
v to perform a single-precision, discrete cosine transform.
- iOS 6.0+
- macOS 10.9+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
NULL, or an existing structure of type
v– i.e. a previous result from any setup function in the single-precision DFT/DCT family:
DSP _DFT _Setup
DSP _DFT _zop _Create Setup(_: _: _:)
v, vDSP_DFT_CreateSetup(_:_:) (deprecated), or
DSP _DFT _zrop _Create Setup(_: _: _:)
DSP _DCT _Create Setup(_: _: _:)
NULLto create an initial setup object.
Number of real elements to be transformed. The supported values are
Length= f * 2**n, where f is 1, 3, 5, or 15 and n is at least 4.
Which DCT variant to perform. At present, the supported DCT types are II and III (which are mutual inverses, up to scaling) and IV (which is its own inverse). These are specified with symbol names
DSP _DCT _II
DSP _DCT _III
DSP _DCT _IV
v object, or
NULL if the function fails, either from lack of memory or because
Type does not satisfy the requirements given above.
The returned setup object may be used only with
v using an input vector of length
Do not call this function while any DFT or DCT routine sharing the
Previous setup data might be executing.