From 11b775881563f3d4aad2b4f9e679d81e2b53f29a Mon Sep 17 00:00:00 2001 From: Christophe Favergeon Date: Fri, 29 May 2020 07:59:39 +0200 Subject: [PATCH] CMSIS-DSP: Corrected issue #906 --- Source/TransformFunctions/arm_rfft_f32.c | 7 +++++++ Source/TransformFunctions/arm_rfft_q15.c | 6 ++++++ Source/TransformFunctions/arm_rfft_q31.c | 7 +++++++ 3 files changed, 20 insertions(+) diff --git a/Source/TransformFunctions/arm_rfft_f32.c b/Source/TransformFunctions/arm_rfft_f32.c index a1fc70ff..e3beed83 100644 --- a/Source/TransformFunctions/arm_rfft_f32.c +++ b/Source/TransformFunctions/arm_rfft_f32.c @@ -85,6 +85,13 @@ void arm_split_rifft_f32( @param[in] pSrc points to the input buffer @param[out] pDst points to the output buffer @return none + + @par + For the RIFFT, the source buffer must at least have length + fftLenReal + 2. + The last two elements must be equal to what would be generated + by the RFFT: + (pSrc[0] - pSrc[1]) and 0.0f */ void arm_rfft_f32( diff --git a/Source/TransformFunctions/arm_rfft_q15.c b/Source/TransformFunctions/arm_rfft_q15.c index 8f19e8de..3f9e4828 100644 --- a/Source/TransformFunctions/arm_rfft_q15.c +++ b/Source/TransformFunctions/arm_rfft_q15.c @@ -71,6 +71,12 @@ void arm_split_rifft_q15( @par If the input buffer is of length N, the output buffer must have length 2*N. The input buffer is modified by this function. + @par + For the RIFFT, the source buffer must at least have length + fftLenReal + 2. + The last two elements must be equal to what would be generated + by the RFFT: + (pSrc[0] - pSrc[1]) >> 1 and 0 */ void arm_rfft_q15( diff --git a/Source/TransformFunctions/arm_rfft_q31.c b/Source/TransformFunctions/arm_rfft_q31.c index bb11f1bb..c963d337 100644 --- a/Source/TransformFunctions/arm_rfft_q31.c +++ b/Source/TransformFunctions/arm_rfft_q31.c @@ -71,6 +71,13 @@ void arm_split_rifft_q31( @par If the input buffer is of length N, the output buffer must have length 2*N. The input buffer is modified by this function. + @par + For the RIFFT, the source buffer must at least have length + fftLenReal + 2. + The last two elements must be equal to what would be generated + by the RFFT: + (pSrc[0] - pSrc[1]) >> 1 and 0 + */ void arm_rfft_q31(