161 lines
7.1 KiB
C
161 lines
7.1 KiB
C
/*
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This software is part of libcsdr, a set of simple DSP routines for
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Software Defined Radio.
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Copyright (c) 2014, Andras Retzler <randras@sdr.hu>
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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* Neither the name of the copyright holder nor the
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names of its contributors may be used to endorse or promote products
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derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL ANDRAS RETZLER BE LIABLE FOR ANY
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DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#pragma once
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#define MIN_M(x,y) (((x)>(y))?(y):(x))
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/*
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_____ _
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/ ____| | |
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| | ___ _ __ ___ _ __ | | _____ __
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| | / _ \| '_ ` _ \| '_ \| |/ _ \ \/ /
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| |___| (_) | | | | | | |_) | | __/> <
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\_____\___/|_| |_| |_| .__/|_|\___/_/\_\
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*/
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typedef struct complexf_s { float i; float q; } complexf;
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//apply to pointers:
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#define iof(complexf_input_p,i) (*(((float*)complexf_input_p)+2*(i)))
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#define qof(complexf_input_p,i) (*(((float*)complexf_input_p)+2*(i)+1))
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#define absof(complexf_input_p,i) (sqrt(iof(complexf_input_p,i)*iof(complexf_input_p,i)+qof(complexf_input_p,i)*qof(complexf_input_p,i)))
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#define argof(complexf_input_p,i) (atan2(qof(complexf_input_p,i),iof(complexf_input_p,i)))
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#define cmult(cfo, cfi1, cfi2) iof(cfo,0)=iof(cfi1,0)*iof(cfi2,0)-qof(cfi1,0)*qof(cfi2,0);qof(cfo,0)=iof(cfi1,0)*qof(cfi2,0)+iof(cfi2,0)*qof(cfi1,0)
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//(ai+aq*j)*(bi+bq*j)=ai*bi-aq*bq+(aq*bi+ai*bq)*j
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#define cmultadd(cfo, cfi1, cfi2) { iof(cfo,0)+=iof(cfi1,0)*iof(cfi2,0)-qof(cfi1,0)*qof(cfi2,0);qof(cfo,0)+=iof(cfi1,0)*qof(cfi2,0)+iof(cfi2,0)*qof(cfi1,0); }
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#define csetnull(cf) { iof(cf,0)=0.0; qof(cf,0)=0.0; }
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#define e_powj(cf,w) { iof(cf,0)=cos(w); qof(cf,0)=sin(w); }
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#define ccopy(dst,src) { iof(dst,0)=iof(src,0); qof(dst,0)=qof(src,0); }
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//apply to values
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#define iofv(complexf_input) (*((float*)&complexf_input))
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#define qofv(complexf_input) (*(((float*)&complexf_input)+1))
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//they dropped M_PI in C99, so we define it:
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#define PI ((float)3.14159265358979323846)
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//window
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typedef enum window_s
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{
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WINDOW_BOXCAR, WINDOW_BLACKMAN, WINDOW_HAMMING
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} window_t;
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#define WINDOW_DEFAULT WINDOW_HAMMING
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//FFT
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//Note: these reference to things in this file (e.g. complexf):
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#include "fft_fftw.h"
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#include "fft_rpi.h"
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// =================================================================================
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//filter design
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void firdes_lowpass_f(float *output, int length, float cutoff_rate, window_t window);
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void firdes_bandpass_c(complexf *output, int length, float lowcut, float highcut, window_t window);
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float firdes_wkernel_blackman(float input);
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float firdes_wkernel_hamming(float input);
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float firdes_wkernel_boxcar(float input);
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window_t firdes_get_window_from_string(char* input);
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char* firdes_get_string_from_window(window_t window);
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int firdes_filter_len(float rolloff);
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//demodulators
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complexf fmdemod_quadri_cf(complexf* input, float* output, int input_size, float *temp, complexf last_sample);
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complexf fmdemod_quadri_novect_cf(complexf* input, float* output, int input_size, complexf last_sample);
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float fmdemod_atan_cf(complexf* input, float *output, int input_size, float last_phase);
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void amdemod_cf(complexf* input, float *output, int input_size);
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void amdemod_estimator_cf(complexf* input, float *output, int input_size, float alpha, float beta);
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void limit_ff(float* input, float* output, int input_size, float max_amplitude);
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//filters, decimators, resamplers, shift, etc.
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int fir_decimate_cc(complexf *input, complexf *output, int input_size, int decimation, float *taps, int taps_length);
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int deemphasis_nfm_ff (float* input, float* output, int input_size, int sample_rate);
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float deemphasis_wfm_ff (float* input, float* output, int input_size, float tau, int sample_rate, float last_output);
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float shift_math_cc(complexf *input, complexf* output, int input_size, float rate, float starting_phase);
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typedef struct dcblock_preserve_s
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{
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float last_input;
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float last_output;
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} dcblock_preserve_t;
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dcblock_preserve_t dcblock_ff(float* input, float* output, int input_size, float a, dcblock_preserve_t preserved);
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float fastdcblock_ff(float* input, float* output, int input_size, float last_dc_level);
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typedef struct fastagc_ff_s
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{
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float* buffer_1;
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float* buffer_2;
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float* buffer_input; //it is the actual input buffer to fill
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float peak_1;
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float peak_2;
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int input_size;
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float reference;
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float last_gain;
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} fastagc_ff_t;
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void fastagc_ff(fastagc_ff_t* input, float* output);
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typedef struct rational_resampler_ff_s
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{
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int input_processed;
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int output_size;
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int last_taps_delay;
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} rational_resampler_ff_t;
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rational_resampler_ff_t rational_resampler_ff(float *input, float *output, int input_size, int interpolation, int decimation, float *taps, int taps_length, int last_taps_delay);
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void rational_resampler_get_lowpass_f(float* output, int output_size, int interpolation, int decimation, window_t window);
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void apply_window_c(complexf* input, complexf* output, int size, window_t window);
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void apply_window_f(float* input, float* output, int size, window_t window);
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void logpower_cf(complexf* input, float* output, int size, float add_db);
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typedef struct fractional_decimator_ff_s
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{
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float remain;
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int input_processed;
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int output_size;
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} fractional_decimator_ff_t;
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fractional_decimator_ff_t fractional_decimator_ff(float* input, float* output, int input_size, float rate, float *taps, int taps_length, fractional_decimator_ff_t d);
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int log2n(int x);
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int next_pow2(int x);
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void apply_fir_fft_cc(FFT_PLAN_T* plan, FFT_PLAN_T* plan_inverse, complexf* taps_fft, complexf* last_overlap, int overlap_size);
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void gain_ff(float* input, float* output, int input_size, float gain);
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void convert_u8_f(unsigned char* input, float* output, int input_size);
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void convert_f_u8(float* input, unsigned char* output, int input_size);
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void convert_f_i16(float* input, short* output, int input_size);
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void convert_i16_f(short* input, float* output, int input_size);
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