kopia lustrzana https://github.com/ha7ilm/csdr
FastDDC code added, and now it builds!
ha7ilm
rodzic
cb1b6ac8e2
commit
edc2c21e43
102
csdr.c
102
csdr.c
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@ -48,6 +48,8 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "ima_adpcm.h"
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#include <sched.h>
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#include <math.h>
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#include <strings.h>
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#include "fastddc.h"
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char usage[]=
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"csdr - a simple commandline tool for Software Defined Radio receiver DSP.\n\n"
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@ -1269,7 +1271,6 @@ int main(int argc, char *argv[])
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float high_cut;
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float transition_bw;
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window_t window = WINDOW_DEFAULT;
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char window_string[256]; //TODO: nice buffer overflow opportunity
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int fd;
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if(fd=init_fifo(argc,argv))
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@ -1646,6 +1647,105 @@ int main(int argc, char *argv[])
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}
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}
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if( !strcmp(argv[1],"fastddc_fwd_cc") ) //<decimation> [transition_bw [window]]
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{
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int decimation;
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if(argc<=2) return badsyntax("need required parameter (decimation)");
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sscanf(argv[2],"%d",&decimation);
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float transition_bw = 0.05;
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if(argc>=3) sscanf(argv[3],"%g",&transition_bw);
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window_t window = WINDOW_DEFAULT;
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if(argc>=4) window=firdes_get_window_from_string(argv[5]);
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else fprintf(stderr,"fastddc_fwd_cc: window = %s\n",firdes_get_string_from_window(window));
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fastddc_t ddc;
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if(fastddc_init(&ddc, transition_bw, decimation, 0)) { badsyntax("error in fastddc_init()"); return 1; }
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fastddc_print(&ddc);
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if(!initialize_buffers()) return -2;
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sendbufsize(ddc.fft_size);
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//make FFT plan
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complexf* input = (complexf*)fft_malloc(sizeof(complexf)*ddc.fft_size);
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complexf* windowed = (complexf*)fft_malloc(sizeof(complexf)*ddc.fft_size);
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complexf* output = (complexf*)fft_malloc(sizeof(complexf)*ddc.fft_size);
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for(int i=0;i<ddc.fft_size;i++) iof(input,i)=qof(input,i)=0; //null the input buffer
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int benchmark = 1;
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if(benchmark) fprintf(stderr,"fastddc_fwd_cc: benchmarking FFT...");
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FFT_PLAN_T* plan=make_fft_c2c(ddc.fft_size, windowed, output, 1, benchmark);
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if(benchmark) fprintf(stderr," done\n");
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for(;;)
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{
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FEOF_CHECK;
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//overlapped FFT
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for(int i=0;i<ddc.overlap_length;i++) input[i]=input[i+ddc.input_size];
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fread(input+ddc.overlap_length, sizeof(complexf), ddc.input_size, stdin);
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apply_window_c(input,windowed,ddc.fft_size,window);
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fft_execute(plan);
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fwrite(output, sizeof(complexf), ddc.fft_size, stdout);
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TRY_YIELD;
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}
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}
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if( !strcmp(argv[1],"fastddc_apply_cc") ) //<decimation> <shift_rate> [transition_bw [window]]
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{
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int decimation;
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if(argc<=2) return badsyntax("need required parameter (decimation)");
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sscanf(argv[2],"%d",&decimation);
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float shift_rate;
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if(argc>=3) sscanf(argv[3],"%g",&shift_rate);
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float transition_bw = 0.05;
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if(argc>=4) sscanf(argv[4],"%g",&transition_bw);
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window_t window = WINDOW_DEFAULT;
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if(argc>=5) window=firdes_get_window_from_string(argv[5]);
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else fprintf(stderr,"fastddc_apply_cc: window = %s\n",firdes_get_string_from_window(window));
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fastddc_t ddc;
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if(fastddc_init(&ddc, transition_bw, decimation, shift_rate)) { badsyntax("error in fastddc_init()"); return 1; }
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fastddc_print(&ddc);
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if(!initialize_buffers()) return -2;
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sendbufsize(ddc.output_size);
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//prepare making the filter and doing FFT on it
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complexf* taps=(complexf*)calloc(sizeof(complexf),ddc.fft_size); //initialize to zero
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complexf* taps_fft=(complexf*)malloc(sizeof(complexf)*ddc.fft_size);
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FFT_PLAN_T* plan_taps = make_fft_c2c(ddc.fft_size, taps, taps_fft, 1, 0); //forward, don't benchmark (we need this only once)
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//make the filter
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float filter_half_bw = 0.5/decimation;
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firdes_bandpass_c(taps, ddc.taps_real_length, shift_rate-filter_half_bw, shift_rate+filter_half_bw, window);
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fft_execute(plan_taps);
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//make FFT plan
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complexf* input = (complexf*)fft_malloc(sizeof(complexf)*ddc.fft_size);
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complexf* output = (complexf*)fft_malloc(sizeof(complexf)*ddc.output_size);
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int benchmark = 1;
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if(benchmark) fprintf(stderr,"fastddc_apply_cc: benchmarking FFT...");
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FFT_PLAN_T* plan_inverse = make_fft_c2c(ddc.fft_size, input, output, 0, 1); //inverse, do benchmark
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if(benchmark) fprintf(stderr," done\n");
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decimating_shift_addition_status_t shift_stat;
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bzero(&shift_stat, sizeof(shift_stat));
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for(;;)
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{
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FEOF_CHECK;
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fread(input, sizeof(complexf), ddc.fft_size, stdin);
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shift_stat = fastddc_apply_cc(input, output, &ddc, plan_inverse, taps_fft, shift_stat);
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fwrite(output, sizeof(complexf), ddc.output_size, stdout);
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TRY_YIELD;
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}
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}
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if(!strcmp(argv[1],"none"))
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{
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return 0;
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@ -0,0 +1,125 @@
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/*
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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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#include "fastddc.h"
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//DDC implementation based on:
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//http://www.3db-labs.com/01598092_MultibandFilterbank.pdf
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inline int is_integer(float a) { return floorf(a) == a; }
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int fastddc_init(fastddc_t* ddc, float transition_bw, int decimation, float shift_rate)
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{
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ddc->pre_decimation = 1; //this will be done in the frequency domain
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ddc->post_decimation = decimation; //this will be done in the time domain
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while( is_integer((float)ddc->post_decimation/2) && ddc->post_decimation/2 != 1)
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{
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ddc->post_decimation/=2;
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ddc->pre_decimation*=2;
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}
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ddc->taps_real_length = firdes_filter_len(transition_bw); //the number of non-zero taps
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ddc->taps_length = ceil(ddc->taps_real_length/(float)ddc->pre_decimation) * ddc->pre_decimation; //the number of taps must be a multiple of the decimation factor
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ddc->fft_size = next_pow2(ddc->taps_length * 4); //it is a good rule of thumb for performance (based on the article), but we should do benchmarks
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while (ddc->fft_size<ddc->pre_decimation) ddc->fft_size*=2; //fft_size should be a multiple of pre_decimation
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ddc->overlap_length = ddc->taps_length - 1;
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ddc->input_size = ddc->fft_size - ddc->overlap_length;
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ddc->fft_inv_size = ddc->fft_size / ddc->pre_decimation;
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//Shift operation in the frequency domain: we can shift by a multiple of v.
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ddc->v = ddc->fft_size/ddc->overlap_length; //+-1 ? (or maybe ceil() this?) //TODO: why?
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int middlebin=ddc->fft_size / 2;
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ddc->startbin = middlebin + middlebin * shift_rate * 2;
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ddc->startbin = ddc->v * round( ddc->startbin / (float)ddc->v );
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ddc->offsetbin = ddc->startbin - middlebin;
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ddc->post_shift = ((float)ddc->offsetbin/ddc->fft_size) - shift_rate;
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ddc->pre_shift = ddc->offsetbin * ddc->v;
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//Overlap is scraped, not added
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ddc->scrape=ddc->overlap_length/ddc->pre_decimation;
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ddc->output_size=ddc->fft_inv_size-ddc->scrape;
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return ddc->fft_size<=2; //returns true on error
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}
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void fastddc_print(fastddc_t* ddc)
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{
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fprintf(stderr,
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"fastddc_print_sizes(): (fft_size = %d) = (taps_length = %d) + (input_size = %d) - 1\n"
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"\t(overlap_length = %d) = taps_length - 1, taps_real_length = %d\n"
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"\tdecimation = (pre_decimation = %d) * (post_decimation = %d), fft_inv_size = %d\n"
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"\tstartbin = %d, offsetbin = %d, v = %d, pre_shift = %g, post_shift = %g\n"
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,
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ddc->fft_size, ddc->taps_length, ddc->input_size,
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ddc->overlap_length, ddc->taps_real_length,
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ddc->pre_decimation, ddc->post_decimation, ddc->fft_inv_size,
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ddc->startbin, ddc->offsetbin, ddc->v, ddc->pre_shift, ddc->post_shift );
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}
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decimating_shift_addition_status_t fastddc_apply_cc(complexf* input, complexf* output, fastddc_t* ddc, FFT_PLAN_T* plan_inverse, complexf* taps_fft, decimating_shift_addition_status_t shift_stat)
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{
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//implements DDC by using the overlap & scrape method
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//TODO: +/-1s on overlap_size et al
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//input shoud have ddc->fft_size number of elements
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complexf* inv_input = plan_inverse->input;
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complexf* inv_output = plan_inverse->output;
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//Initialize buffers for inverse FFT to zero
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for(int i=0;i<plan_inverse->size;i++)
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{
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iof(inv_input,i)=0;
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qof(inv_input,i)=0;
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}
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//Alias & shift & filter at once
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// * no, we won't break this algorithm to parts that are easier to understand: now we go for speed
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for(int i=0;i<ddc->fft_size;i++)
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{
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int output_index = (ddc->startbin+i)%plan_inverse->size;
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int tap_index = (ddc->fft_size+i-ddc->offsetbin)%ddc->fft_size;
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cmultadd(inv_input+output_index, input+i, taps_fft+tap_index); //cmultadd(output, input1, input2): complex output += complex input1 * complex input 2
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}
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fft_execute(plan_inverse);
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//Normalize data
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for(int i=0;i<plan_inverse->size;i++) //@apply_ddc_fft_cc: normalize by size
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{
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iof(inv_output,i)/=plan_inverse->size;
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qof(inv_output,i)/=plan_inverse->size;
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}
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//Overlap is scraped, not added
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//Shift correction
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shift_addition_data_t dsadata=decimating_shift_addition_init(ddc->post_shift, ddc->post_decimation); //this could be optimized (passed as parameter), but we would not win too much at all
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shift_stat=decimating_shift_addition_cc(plan_inverse->output+ddc->scrape, output, ddc->output_size, dsadata, ddc->post_decimation, shift_stat);
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return shift_stat;
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}
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@ -0,0 +1,27 @@
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#include <math.h>
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#include "libcsdr.h"
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#include "libcsdr_gpl.h"
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typedef struct fastddc_s
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{
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int pre_decimation;
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int post_decimation;
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int taps_length;
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int taps_real_length;
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int overlap_length; //it is taps_length - 1
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int fft_size;
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int fft_inv_size;
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int input_size;
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int output_size;
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float pre_shift;
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int startbin; //for pre_shift
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int v; //step for pre_shift
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int offsetbin;
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float post_shift;
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int output_scrape;
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int scrape;
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} fastddc_t;
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int fastddc_init(fastddc_t* ddc, float transition_bw, int decimation, float shift_rate);
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decimating_shift_addition_status_t fastddc_apply_cc(complexf* input, complexf* output, fastddc_t* ddc, FFT_PLAN_T* plan_inverse, complexf* taps_fft, decimating_shift_addition_status_t shift_stat);
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void fastddc_print(fastddc_t* ddc);
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@ -1,4 +1,5 @@
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#include "libcsdr.c"
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#include "libcsdr_gpl.c"
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#include "ima_adpcm.c"
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#include "fastddc.c"
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//this wrapper helps parsevect.py to generate better output
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