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Merge pull request #19 from tejeez/master

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FFT improvements from @teejez
This commit is contained in:
András Retzler 2016-10-29 19:42:56 +02:00 committed by GitHub
commit 1080e4ad23
3 changed files with 78 additions and 1 deletions
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39
csdr.c
View file

@ -1275,6 +1275,8 @@ int main(int argc, char *argv[])
FFT_PLAN_T* plan=make_fft_c2c(fft_size, windowed, output, 1, benchmark);
if(benchmark) fprintf(stderr," done\n");
if(octave) printf("setenv(\"GNUTERM\",\"X11 noraise\");y=zeros(1,%d);semilogy(y,\"ydatasource\",\"y\");\n",fft_size);
float *windowt;
windowt = precalculate_window(fft_size, window);
for(;;)
{
FEOF_CHECK;
@ -1293,7 +1295,8 @@ int main(int argc, char *argv[])
for(int i=0;i<fft_size-every_n_samples;i++) input[i]=input[i+every_n_samples];
fread(input+fft_size-every_n_samples, sizeof(complexf), every_n_samples, stdin);
}
apply_window_c(input,windowed,fft_size,window);
//apply_window_c(input,windowed,fft_size,window);
apply_precalculated_window_c(input,windowed,fft_size,windowt);
fft_execute(plan);
if(octave)
{
@ -1329,6 +1332,40 @@ int main(int argc, char *argv[])
}
}
if(!strcmp(argv[1],"logaveragepower_cf"))
{
bigbufs=1;
if(argc<=4) return badsyntax("need required parameters (add_db, table_size, avgnumber)");
float add_db=0;
int avgnumber=0;
int fft_size=0;
sscanf(argv[2],"%g",&add_db);
sscanf(argv[3],"%d",&fft_size);
sscanf(argv[4],"%d",&avgnumber);
float *input = malloc(sizeof(float)*2 * fft_size);
float *output = malloc(sizeof(float) * fft_size);
add_db -= 10.0*log10(avgnumber);
for(;;)
{
int i,n;
for(i = 0; i < fft_size; i++) {
output[i] = 0;
}
FEOF_CHECK;
for(n = 0; n < avgnumber; n++) {
fread (input, sizeof(float)*2, fft_size, stdin);
accumulate_power_cf((complexf*)input, output, fft_size);
}
log_ff(output, output, fft_size, add_db);
fwrite (output, sizeof(float), fft_size, stdout);
TRY_YIELD;
}
return 0;
}
if(!strcmp(argv[1],"fft_exchange_sides_ff"))
{
if(argc<=2) return badsyntax("need required parameters (fft_size)");

36
libcsdr.c
View file

@ -930,6 +930,29 @@ void apply_window_c(complexf* input, complexf* output, int size, window_t window
}
}
float *precalculate_window(int size, window_t window)
{
float (*window_function)(float)=firdes_get_window_kernel(window);
float *windowt;
windowt = malloc(sizeof(float) * size);
for(int i=0;i<size;i++) //@precalculate_window
{
float rate=(float)i/(size-1);
windowt[i] = window_function(2.0*rate+1.0);
}
return windowt;
}
void apply_precalculated_window_c(complexf* input, complexf* output, int size, float *windowt)
{
for(int i=0;i<size;i++) //@apply_precalculated_window_c
{
iof(output,i)=iof(input,i)*windowt[i];
qof(output,i)=qof(input,i)*windowt[i];
}
}
void apply_window_f(float* input, float* output, int size, window_t window)
{
float (*window_function)(float)=firdes_get_window_kernel(window);
@ -949,6 +972,19 @@ void logpower_cf(complexf* input, float* output, int size, float add_db)
for(int i=0;i<size;i++) output[i]=10*output[i]+add_db; //@logpower_cf: pass 3
}
void accumulate_power_cf(complexf* input, float* output, int size)
{
for(int i=0;i<size;i++) output[i] += iof(input,i)*iof(input,i) + qof(input,i)*qof(input,i); //@logpower_cf: pass 1
}
void log_ff(float* input, float* output, int size, float add_db) {
for(int i=0;i<size;i++) output[i]=log10(input[i]); //@logpower_cf: pass 2
for(int i=0;i<size;i++) output[i]=10*output[i]+add_db; //@logpower_cf: pass 3
}
/*
_____ _ _
| __ \ | | (_)

4
libcsdr.h
View file

@ -135,9 +135,13 @@ typedef struct rational_resampler_ff_s
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);
void rational_resampler_get_lowpass_f(float* output, int output_size, int interpolation, int decimation, window_t window);
float *precalculate_window(int size, window_t window);
void apply_window_c(complexf* input, complexf* output, int size, window_t window);
void apply_precalculated_window_c(complexf* input, complexf* output, int size, float *windowt);
void apply_window_f(float* input, float* output, int size, window_t window);
void logpower_cf(complexf* input, float* output, int size, float add_db);
void accumulate_power_cf(complexf* input, float* output, int size);
void log_ff(float* input, float* output, int size, float add_db);
typedef struct fractional_decimator_ff_s
{