From 96d6da4e252b06dcfdc041e7df23e86161c33007 Mon Sep 17 00:00:00 2001 From: rihab kouki Date: Tue, 28 Jul 2020 11:24:49 +0100 Subject: Official ARM version: v5.6.0 --- docs/DSP/html/group__RealFFT.html | 423 +++++++++++++++++++++++++++++++------- 1 file changed, 347 insertions(+), 76 deletions(-) (limited to 'docs/DSP/html/group__RealFFT.html') diff --git a/docs/DSP/html/group__RealFFT.html b/docs/DSP/html/group__RealFFT.html index 3f28e0d..d57ec40 100644 --- a/docs/DSP/html/group__RealFFT.html +++ b/docs/DSP/html/group__RealFFT.html @@ -32,7 +32,7 @@ Logo
CMSIS-DSP -  Version 1.5.2 +  Version 1.7.0
CMSIS DSP Software Library
@@ -128,10 +128,35 @@ Functions void arm_rfft_fast_f32 (arm_rfft_fast_instance_f32 *S, float32_t *p, float32_t *pOut, uint8_t ifftFlag)  Processing function for the floating-point real FFT. More...
  +arm_status arm_rfft_32_fast_init_f32 (arm_rfft_fast_instance_f32 *S) + Initialization function for the 32pt floating-point real FFT. More...
+  +arm_status arm_rfft_64_fast_init_f32 (arm_rfft_fast_instance_f32 *S) + Initialization function for the 64pt floating-point real FFT. More...
+  +arm_status arm_rfft_128_fast_init_f32 (arm_rfft_fast_instance_f32 *S) + Initialization function for the 128pt floating-point real FFT. More...
+  +arm_status arm_rfft_256_fast_init_f32 (arm_rfft_fast_instance_f32 *S) + Initialization function for the 256pt floating-point real FFT. More...
+  +arm_status arm_rfft_512_fast_init_f32 (arm_rfft_fast_instance_f32 *S) + Initialization function for the 512pt floating-point real FFT. More...
+  +arm_status arm_rfft_1024_fast_init_f32 (arm_rfft_fast_instance_f32 *S) + Initialization function for the 1024pt floating-point real FFT. More...
+  +arm_status arm_rfft_2048_fast_init_f32 (arm_rfft_fast_instance_f32 *S) + Initialization function for the 2048pt floating-point real FFT. More...
+  +arm_status arm_rfft_4096_fast_init_f32 (arm_rfft_fast_instance_f32 *S) + Initialization function for the 4096pt floating-point real FFT. More...
+  arm_status arm_rfft_fast_init_f32 (arm_rfft_fast_instance_f32 *S, uint16_t fftLen)  Initialization function for the floating-point real FFT. More...
  arm_status arm_rfft_init_f32 (arm_rfft_instance_f32 *S, arm_cfft_radix4_instance_f32 *S_CFFT, uint32_t fftLenReal, uint32_t ifftFlagR, uint32_t bitReverseFlag) + Initialization function for the floating-point RFFT/RIFFT. More...
  arm_status arm_rfft_init_q15 (arm_rfft_instance_q15 *S, uint32_t fftLenReal, uint32_t ifftFlagR, uint32_t bitReverseFlag)  Initialization function for the Q15 RFFT/RIFFT. More...
@@ -154,16 +179,16 @@ Functions RFFT.gif
Real Fast Fourier Transform
- +
The real sequence is initially treated as if it were complex to perform a CFFT. Later, a processing stage reshapes the data to obtain half of the frequency spectrum in complex format. Except the first complex number that contains the two real numbers X[0] and X[N/2] all the data is complex. In other words, the first complex sample contains two real values packed.
The input for the inverse RFFT should keep the same format as the output of the forward RFFT. A first processing stage pre-process the data to later perform an inverse CFFT.
RIFFT.gif
Real Inverse Fast Fourier Transform
-
+
The algorithms for floating-point, Q15, and Q31 data are slightly different and we describe each algorithm in turn.
-
Floating-point
The main functions are arm_rfft_fast_f32() and arm_rfft_fast_init_f32(). The older functions arm_rfft_f32() and arm_rfft_init_f32() have been deprecated but are still documented.
+
Floating-point
The main functions are arm_rfft_fast_f32() and arm_rfft_fast_init_f32(). The older functions arm_rfft_f32() and arm_rfft_init_f32() have been deprecated but are still documented.
The FFT of a real N-point sequence has even symmetry in the frequency domain. The second half of the data equals the conjugate of the first half flipped in frequency. Looking at the data, we see that we can uniquely represent the FFT using only N/2 complex numbers. These are packed into the output array in alternating real and imaginary components:
X = { real[0], imag[0], real[1], imag[1], real[2], imag[2] ... real[(N/2)-1], imag[(N/2)-1 }
It happens that the first complex number (real[0], imag[0]) is actually all real. real[0] represents the DC offset, and imag[0] should be 0. (real[1], imag[1]) is the fundamental frequency, (real[2], imag[2]) is the first harmonic and so on.
@@ -178,11 +203,226 @@ Real Inverse Fast Fourier Transform
Use of the initialization function is optional. However, if the initialization function is used, then the instance structure cannot be placed into a const data section. To place an instance structure into a const data section, the instance structure should be manually initialized as follows: 
-arm_rfft_instance_q31 S = {fftLenReal, fftLenBy2, ifftFlagR, bitReverseFlagR, twidCoefRModifier, pTwiddleAReal, pTwiddleBReal, pCfft};
-arm_rfft_instance_q15 S = {fftLenReal, fftLenBy2, ifftFlagR, bitReverseFlagR, twidCoefRModifier, pTwiddleAReal, pTwiddleBReal, pCfft};
-
where fftLenReal is the length of the real transform; fftLenBy2 length of the internal complex transform. ifftFlagR Selects forward (=0) or inverse (=1) transform. bitReverseFlagR Selects bit reversed output (=0) or normal order output (=1). twidCoefRModifier stride modifier for the twiddle factor table. The value is based on the FFT length; pTwiddleARealpoints to the A array of twiddle coefficients; pTwiddleBRealpoints to the B array of twiddle coefficients; pCfft points to the CFFT Instance structure. The CFFT structure must also be initialized. Refer to arm_cfft_radix4_f32() for details regarding static initialization of the complex FFT instance structure.
-

end of RealFFT_Table group

+ arm_rfft_instance_q31 S = {fftLenReal, fftLenBy2, ifftFlagR, bitReverseFlagR, twidCoefRModifier, pTwiddleAReal, pTwiddleBReal, pCfft}; + arm_rfft_instance_q15 S = {fftLenReal, fftLenBy2, ifftFlagR, bitReverseFlagR, twidCoefRModifier, pTwiddleAReal, pTwiddleBReal, pCfft}; + where fftLenReal is the length of the real transform; fftLenBy2 length of the internal complex transform. ifftFlagR Selects forward (=0) or inverse (=1) transform. bitReverseFlagR Selects bit reversed output (=0) or normal order output (=1). twidCoefRModifier stride modifier for the twiddle factor table. The value is based on the FFT length; pTwiddleARealpoints to the A array of twiddle coefficients; pTwiddleBRealpoints to the B array of twiddle coefficients; pCfft points to the CFFT Instance structure. The CFFT structure must also be initialized. Refer to arm_cfft_radix4_f32() for details regarding static initialization of the complex FFT instance structure.

Function Documentation

+ +
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arm_status arm_rfft_1024_fast_init_f32 (arm_rfft_fast_instance_f32 * S)
+
+
Parameters
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[in,out]Spoints to an arm_rfft_fast_instance_f32 structure
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+
Returns
execution status +
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arm_status arm_rfft_128_fast_init_f32 (arm_rfft_fast_instance_f32 * S)
+
+
Parameters
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[in,out]Spoints to an arm_rfft_fast_instance_f32 structure
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+
Returns
execution status +
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arm_status arm_rfft_2048_fast_init_f32 (arm_rfft_fast_instance_f32 * S)
+
+
Parameters
+ + +
[in,out]Spoints to an arm_rfft_fast_instance_f32 structure
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Returns
execution status +
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arm_status arm_rfft_256_fast_init_f32 (arm_rfft_fast_instance_f32 * S)
+
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Parameters
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[in,out]Spoints to an arm_rfft_fast_instance_f32 structure
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Returns
execution status +
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arm_status arm_rfft_32_fast_init_f32 (arm_rfft_fast_instance_f32 * S)
+
+
Parameters
+ + +
[in,out]Spoints to an arm_rfft_fast_instance_f32 structure
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Returns
execution status +
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arm_status arm_rfft_4096_fast_init_f32 (arm_rfft_fast_instance_f32 * S)
+
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Parameters
+ + +
[in,out]Spoints to an arm_rfft_fast_instance_f32 structure
+
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Returns
execution status +
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arm_status arm_rfft_512_fast_init_f32 (arm_rfft_fast_instance_f32 * S)
+
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Parameters
+ + +
[in,out]Spoints to an arm_rfft_fast_instance_f32 structure
+
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Returns
execution status +
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arm_status arm_rfft_64_fast_init_f32 (arm_rfft_fast_instance_f32 * S)
+
+
Parameters
+ + +
[in,out]Spoints to an arm_rfft_fast_instance_f32 structure
+
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Returns
execution status +
+ +
+
@@ -212,19 +452,17 @@ Real Inverse Fast Fourier Transform
-
Deprecated:
Do not use this function. It has been superceded by arm_rfft_fast_f32 and will be removed in the future.
Parameters
+
Deprecated:
Do not use this function. It has been superceded by arm_rfft_fast_f32 and will be removed in the future.
Parameters
- - - + + +
[in]*Spoints to an instance of the floating-point RFFT/RIFFT structure.
[in]*pSrcpoints to the input buffer.
[out]*pDstpoints to the output buffer.
[in]Spoints to an instance of the floating-point RFFT/RIFFT structure
[in]pSrcpoints to the input buffer
[out]pDstpoints to the output buffer
-
Returns
none.
+
Returns
none
-

References arm_bitreversal_f32(), arm_radix4_butterfly_f32(), arm_radix4_butterfly_inverse_f32(), arm_split_rfft_f32(), arm_split_rifft_f32(), arm_rfft_instance_f32::bitReverseFlagR, arm_cfft_radix4_instance_f32::bitRevFactor, arm_cfft_radix4_instance_f32::fftLen, arm_rfft_instance_f32::fftLenBy2, arm_rfft_instance_f32::ifftFlagR, arm_cfft_radix4_instance_f32::onebyfftLen, arm_cfft_radix4_instance_f32::pBitRevTable, arm_rfft_instance_f32::pCfft, arm_cfft_radix4_instance_f32::pTwiddle, arm_rfft_instance_f32::pTwiddleAReal, arm_rfft_instance_f32::pTwiddleBReal, arm_cfft_radix4_instance_f32::twidCoefModifier, and arm_rfft_instance_f32::twidCoefRModifier.

-
@@ -264,16 +502,18 @@ Real Inverse Fast Fourier Transform
Parameters
- - - - + + + +
[in]*Spoints to an arm_rfft_fast_instance_f32 structure.
[in]*ppoints to the input buffer.
[in]*pOutpoints to the output buffer.
[in]ifftFlagRFFT if flag is 0, RIFFT if flag is 1
[in]Spoints to an arm_rfft_fast_instance_f32 structure
[in]ppoints to input buffer
[in]pOutpoints to output buffer
[in]ifftFlag
    +
  • value = 0: RFFT
    • +
  • value = 1: RIFFT
    • +
+
-
Returns
none.
- -

References arm_cfft_f32(), arm_cfft_instance_f32::fftLen, arm_rfft_fast_instance_f32::fftLenRFFT, merge_rfft_f32(), arm_rfft_fast_instance_f32::Sint, and stage_rfft_f32().

+
Returns
none
@@ -302,18 +542,19 @@ Real Inverse Fast Fourier Transform
Parameters
- - + +
[in,out]*Spoints to an arm_rfft_fast_instance_f32 structure.
[in]fftLenlength of the Real Sequence.
[in,out]Spoints to an arm_rfft_fast_instance_f32 structure
[in]fftLenlength of the Real Sequence
-
Returns
The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if fftLen is not a supported value.
-
Description:
-
The parameter fftLen Specifies length of RFFT/CIFFT process. Supported FFT Lengths are 32, 64, 128, 256, 512, 1024, 2048, 4096.
+
Returns
execution status +
+
Description
The parameter fftLen specifies the length of RFFT/CIFFT process. Supported FFT Lengths are 32, 64, 128, 256, 512, 1024, 2048, 4096.
This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
-

References ARM_MATH_ARGUMENT_ERROR, ARM_MATH_SUCCESS, armBitRevIndexTable1024, armBitRevIndexTable128, armBitRevIndexTable16, armBitRevIndexTable2048, armBitRevIndexTable256, armBitRevIndexTable32, armBitRevIndexTable512, armBitRevIndexTable64, ARMBITREVINDEXTABLE_1024_TABLE_LENGTH, ARMBITREVINDEXTABLE_128_TABLE_LENGTH, ARMBITREVINDEXTABLE_16_TABLE_LENGTH, ARMBITREVINDEXTABLE_2048_TABLE_LENGTH, ARMBITREVINDEXTABLE_256_TABLE_LENGTH, ARMBITREVINDEXTABLE_32_TABLE_LENGTH, ARMBITREVINDEXTABLE_512_TABLE_LENGTH, ARMBITREVINDEXTABLE_64_TABLE_LENGTH, arm_cfft_instance_f32::bitRevLength, arm_cfft_instance_f32::fftLen, arm_rfft_fast_instance_f32::fftLenRFFT, arm_cfft_instance_f32::pBitRevTable, arm_cfft_instance_f32::pTwiddle, arm_rfft_fast_instance_f32::pTwiddleRFFT, arm_rfft_fast_instance_f32::Sint, status, twiddleCoef_1024, twiddleCoef_128, twiddleCoef_16, twiddleCoef_2048, twiddleCoef_256, twiddleCoef_32, twiddleCoef_512, twiddleCoef_64, twiddleCoef_rfft_1024, twiddleCoef_rfft_128, twiddleCoef_rfft_2048, twiddleCoef_rfft_256, twiddleCoef_rfft_32, twiddleCoef_rfft_4096, twiddleCoef_rfft_512, and twiddleCoef_rfft_64.

-
@@ -357,10 +598,34 @@ Real Inverse Fast Fourier Transform
- -

References arm_cfft_radix4_init_f32(), ARM_MATH_ARGUMENT_ERROR, ARM_MATH_SUCCESS, arm_rfft_instance_f32::bitReverseFlagR, arm_rfft_instance_f32::fftLenBy2, arm_rfft_instance_f32::fftLenReal, arm_rfft_instance_f32::ifftFlagR, arm_rfft_instance_f32::pCfft, arm_rfft_instance_f32::pTwiddleAReal, arm_rfft_instance_f32::pTwiddleBReal, realCoefA, realCoefB, status, and arm_rfft_instance_f32::twidCoefRModifier.

- -

Referenced by arm_dct4_init_f32().

+
Deprecated:
Do not use this function. It has been superceded by arm_rfft_fast_init_f32 and will be removed in the future.
Parameters
+ + + + + + +
[in,out]Spoints to an instance of the floating-point RFFT/RIFFT structure
[in,out]S_CFFTpoints to an instance of the floating-point CFFT/CIFFT structure
[in]fftLenReallength of the FFT.
[in]ifftFlagRflag that selects transform direction
    +
  • value = 0: forward transform
    • +
  • value = 1: inverse transform
    • +
+
[in]bitReverseFlagflag that enables / disables bit reversal of output
    +
  • value = 0: disables bit reversal of output
    • +
  • value = 1: enables bit reversal of output
    • +
+
+
+
+
Returns
execution status +
+
+
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.
@@ -401,24 +666,31 @@ Real Inverse Fast Fourier Transform
Parameters
- - - - + + + +
[in,out]*Spoints to an instance of the Q15 RFFT/RIFFT structure.
[in]fftLenReallength of the FFT.
[in]ifftFlagRflag that selects forward (ifftFlagR=0) or inverse (ifftFlagR=1) transform.
[in]bitReverseFlagflag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
[in,out]Spoints to an instance of the Q15 RFFT/RIFFT structure
[in]fftLenReallength of the FFT
[in]ifftFlagRflag that selects transform direction
    +
  • value = 0: forward transform
    • +
  • value = 1: inverse transform
    • +
+
[in]bitReverseFlagflag that enables / disables bit reversal of output
    +
  • value = 0: disables bit reversal of output
    • +
  • value = 1: enables bit reversal of output
    • +
+
-
Returns
The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if fftLenReal is not a supported value.
-
Description:
-
The parameter fftLenReal Specifies length of RFFT/RIFFT Process. Supported FFT Lengths are 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192.
+
Returns
execution status +
+
Details
The parameter fftLenReal specifies length of RFFT/RIFFT Process. Supported FFT Lengths are 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192.
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.
-

References arm_cfft_sR_q15_len1024, arm_cfft_sR_q15_len128, arm_cfft_sR_q15_len16, arm_cfft_sR_q15_len2048, arm_cfft_sR_q15_len256, arm_cfft_sR_q15_len32, arm_cfft_sR_q15_len4096, arm_cfft_sR_q15_len512, arm_cfft_sR_q15_len64, ARM_MATH_ARGUMENT_ERROR, ARM_MATH_SUCCESS, arm_rfft_instance_q15::bitReverseFlagR, arm_rfft_instance_q15::fftLenReal, arm_rfft_instance_q15::ifftFlagR, arm_rfft_instance_q15::pCfft, arm_rfft_instance_q15::pTwiddleAReal, arm_rfft_instance_q15::pTwiddleBReal, realCoefAQ15, realCoefBQ15, status, and arm_rfft_instance_q15::twidCoefRModifier.

- -

Referenced by arm_dct4_init_q15().

-
@@ -458,23 +730,30 @@ Real Inverse Fast Fourier Transform
Parameters
- - - - + + + +
[in,out]*Spoints to an instance of the Q31 RFFT/RIFFT structure.
[in]fftLenReallength of the FFT.
[in]ifftFlagRflag that selects forward (ifftFlagR=0) or inverse (ifftFlagR=1) transform.
[in]bitReverseFlagflag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output.
[in,out]Spoints to an instance of the Q31 RFFT/RIFFT structure
[in]fftLenReallength of the FFT
[in]ifftFlagRflag that selects transform direction
    +
  • value = 0: forward transform
    • +
  • value = 1: inverse transform
    • +
+
[in]bitReverseFlagflag that enables / disables bit reversal of output
    +
  • value = 0: disables bit reversal of output
    • +
  • value = 1: enables bit reversal of output
    • +
+
-
Returns
The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if fftLenReal is not a supported value.
-
Description:
-
The parameter fftLenReal Specifies length of RFFT/RIFFT Process. Supported FFT Lengths are 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192.
+
Returns
execution status +
+
Details
The parameter fftLenReal specifies length of RFFT/RIFFT Process. Supported FFT Lengths are 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192.
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.
-
7
This function also initializes Twiddle factor table.
- -

References arm_cfft_sR_q31_len1024, arm_cfft_sR_q31_len128, arm_cfft_sR_q31_len16, arm_cfft_sR_q31_len2048, arm_cfft_sR_q31_len256, arm_cfft_sR_q31_len32, arm_cfft_sR_q31_len4096, arm_cfft_sR_q31_len512, arm_cfft_sR_q31_len64, ARM_MATH_ARGUMENT_ERROR, ARM_MATH_SUCCESS, arm_rfft_instance_q31::bitReverseFlagR, arm_rfft_instance_q31::fftLenReal, arm_rfft_instance_q31::ifftFlagR, arm_rfft_instance_q31::pCfft, arm_rfft_instance_q31::pTwiddleAReal, arm_rfft_instance_q31::pTwiddleBReal, realCoefAQ31, realCoefBQ31, status, and arm_rfft_instance_q31::twidCoefRModifier.

- -

Referenced by arm_dct4_init_q31().

+
This function also initializes Twiddle factor table.
@@ -509,15 +788,14 @@ Real Inverse Fast Fourier Transform
Parameters
- - - + + +
[in]*Spoints to an instance of the Q15 RFFT/RIFFT structure.
[in]*pSrcpoints to the input buffer.
[out]*pDstpoints to the output buffer.
[in]Spoints to an instance of the Q15 RFFT/RIFFT structure
[in]pSrcpoints to input buffer
[out]pDstpoints to output buffer
-
Returns
none.
-
Input an output formats:
-
Internally input is downscaled by 2 for every stage to avoid saturations inside CFFT/CIFFT process. Hence the output format is different for different RFFT sizes. The input and output formats for different RFFT sizes and number of bits to upscale are mentioned in the tables below for RFFT and RIFFT:
+
Returns
none
+
Input an output formats
Internally input is downscaled by 2 for every stage to avoid saturations inside CFFT/CIFFT process. Hence the output format is different for different RFFT sizes. The input and output formats for different RFFT sizes and number of bits to upscale are mentioned in the tables below for RFFT and RIFFT:
RFFTQ15.gif
@@ -529,8 +807,6 @@ Input and Output Formats for Q15 RFFT
Input and Output Formats for Q15 RIFFT
-

References arm_cfft_q15(), arm_split_rfft_q15(), arm_split_rifft_q15(), arm_rfft_instance_q15::bitReverseFlagR, arm_rfft_instance_q15::fftLenReal, arm_rfft_instance_q15::ifftFlagR, arm_rfft_instance_q15::pCfft, arm_rfft_instance_q15::pTwiddleAReal, arm_rfft_instance_q15::pTwiddleBReal, and arm_rfft_instance_q15::twidCoefRModifier.

- @@ -564,30 +840,25 @@ Input and Output Formats for Q15 RIFFT
Parameters
- - - + + +
[in]*Spoints to an instance of the Q31 RFFT/RIFFT structure.
[in]*pSrcpoints to the input buffer.
[out]*pDstpoints to the output buffer.
[in]Spoints to an instance of the Q31 RFFT/RIFFT structure
[in]pSrcpoints to input buffer
[out]pDstpoints to output buffer
-
Returns
none.
-
Input an output formats:
-
Internally input is downscaled by 2 for every stage to avoid saturations inside CFFT/CIFFT process. Hence the output format is different for different RFFT sizes. The input and output formats for different RFFT sizes and number of bits to upscale are mentioned in the tables below for RFFT and RIFFT:
+
Returns
none
+
Input an output formats
Internally input is downscaled by 2 for every stage to avoid saturations inside CFFT/CIFFT process. Hence the output format is different for different RFFT sizes. The input and output formats for different RFFT sizes and number of bits to upscale are mentioned in the tables below for RFFT and RIFFT:
RFFTQ31.gif
Input and Output Formats for Q31 RFFT
-
+
RIFFTQ31.gif
Input and Output Formats for Q31 RIFFT
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References arm_cfft_q31(), arm_split_rfft_q31(), arm_split_rifft_q31(), arm_rfft_instance_q31::bitReverseFlagR, arm_rfft_instance_q31::fftLenReal, arm_rfft_instance_q31::ifftFlagR, arm_rfft_instance_q31::pCfft, arm_rfft_instance_q31::pTwiddleAReal, arm_rfft_instance_q31::pTwiddleBReal, and arm_rfft_instance_q31::twidCoefRModifier.

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Referenced by arm_dct4_q31().

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@@ -595,7 +866,7 @@ Input and Output Formats for Q31 RIFFT