Deprecated Real FFT Functions

Functions
void	riscv_rfft_f32 (const riscv_rfft_instance_f32 *S, float32_t *pSrc, float32_t *pDst)
	Processing function for the floating-point RFFT/RIFFT. Source buffer is modified by this function. More...
riscv_status	riscv_rfft_init_f32 (riscv_rfft_instance_f32 *S, riscv_cfft_radix4_instance_f32 *S_CFFT, uint32_t fftLenReal, uint32_t ifftFlagR, uint32_t bitReverseFlag)
	Initialization function for the floating-point RFFT/RIFFT. More...

Detailed Description

Function Documentation

riscv_rfft_f32()

void riscv_rfft_f32	(	const riscv_rfft_instance_f32 *	S,
		float32_t *	pSrc,
		float32_t *	pDst
	)

Processing function for the floating-point RFFT/RIFFT. Source buffer is modified by this function.

Deprecated:

Do not use this function. It has been superceded by riscv_rfft_fast_f32 and will be removed in the future.

Parameters

[in]	S	points to an instance of the floating-point RFFT/RIFFT structure
[in]	pSrc	points to the input buffer
[out]	pDst	points to the output buffer

Returns

none

riscv_rfft_init_f32()

riscv_status riscv_rfft_init_f32	(	riscv_rfft_instance_f32 *	S,
		riscv_cfft_radix4_instance_f32 *	S_CFFT,
		uint32_t	fftLenReal,
		uint32_t	ifftFlagR,
		uint32_t	bitReverseFlag
	)

Initialization function for the floating-point RFFT/RIFFT.

Deprecated:

Do not use this function. It has been superceded by riscv_rfft_fast_init_f32 and will be removed in the future.

Parameters

[in,out]	S	points to an instance of the floating-point RFFT/RIFFT structure
[in,out]	S_CFFT	points to an instance of the floating-point CFFT/CIFFT structure
[in]	fftLenReal	length of the FFT.
[in]	ifftFlagR	flag that selects transform direction value = 0: forward transform value = 1: inverse transform
[in]	bitReverseFlag	flag that enables / disables bit reversal of output value = 0: disables bit reversal of output value = 1: enables bit reversal of output

Returns

execution status

• RISCV_MATH_SUCCESS : Operation successful
• RISCV_MATH_ARGUMENT_ERROR : fftLenReal is not a supported length

Description

The parameter fftLenRealspecifies length of RFFT/RIFFT Process. Supported FFT Lengths are 128, 512, 2048.

The parameter ifftFlagR controls whether a forward or inverse transform is computed. Set(=1) ifftFlagR to calculate RIFFT, otherwise RFFT is calculated.

The parameter bitReverseFlag controls whether output is in normal order or bit reversed order. Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.

This function also initializes Twiddle factor table.