Audio: stft_process: Add conversion to polar format and back #10496
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src/math/sqrt_int32.c
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| * fmt=['static int32_t sqrt_int32_lut[] = {' repmat(' %d,',1, numel(lut)-1) ' %d};\n']; | ||
| * fprintf(fmt, lut) | ||
| */ | ||
| static int32_t sqrt_int32_lut[] = { |
The rename is done to avoid possible conflict with other math libraries. The change is done to prepare add of 32 bit square root function. Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
This patch adds a higher precision 32-bit fractional integer square root function to SOF math library. The algorithm uses a lookup table for initial value and two iterations with Newton-Raphson method to improve the accuracy. Both input and output format is Q2.30. The format was chosen to match complex to polar conversions numbers range for Q1.31 complex values. Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
This patch helps with more generic use of complex numbers not directly related to the FFTs domain. It prepares to add polar complex numbers format that is commonly used in frequency domain signal processing. Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
This patch adds functions sofm_icomplex32_to_polar() and sofm_ipolar32_to_complex(). In polar format the Q1.31 (real, imag) numbers pair is converted to (magnitude, angle). The magnitude is Q2.30 format and angle in -pi to +pi radians in Q3.29 format. The conversion to polar and back loses some quality so there currently is no support for icomplex16. Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
The new ztest cases test_icomplex32_to_polar and ipolar32_to_complex test the conversion functions with a pre-calculated -1,+1 box saturated (re, im) spiral shape with 1000 points. Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
This patch adds to stft_process component conversion to polar (magnitude, angle) format for first FFT half from DC to Nyquist frequency. The polar format is converted back to (real, imaginary) complex and upper FFT half symmetry is applied. The magnitude domain is commonly used for signal processing in frequency domain. This change when enabled in Kconfig change increases load in MTL platform from 72 MCPS to 202 MCPS with 1024 size FFT and hop of 256. Currently the build option STFT_PROCESS_MAGNITUDE_PHASE is not set. Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
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lgirdwood
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Jan 27, 2026
| * fmt=['static const int32_t sqrt_int32_lut[] = {' repmat(' %d,',1, numel(lut)-1) ' %d};\n']; | ||
| * fprintf(fmt, lut) | ||
| */ | ||
| static const int32_t sqrt_int32_lut[] = { |
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do we need to vector align this table for SIMD ?
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