Initial file

CMakeLists.txt

+cmake_minimum_required(VERSION 2.6)
+
+subdirs(f_fftw)
\ No newline at end of file

README.md

+
+fftw
+====
+
+Apply a fft on th signal using fftw3.
+
+Install
+=======
+
+Install [blaar](blaar.org) then in the blaar directory:
+
+OSX:
+
+	brew install fftw
+	git submodule add https://framagit.org/blaar/fftw
+	./install.sh fftw
+
+
+Ubuntu:
+
+    sudo apt-get install fftw3-dev
+    git submodule add https://framagit.org/blaar/fftw
+    ./install.sh fftw
+
+Usage:
+======
+	
+	bin/f_fftw <blc_channel-in>

f_fftw/CMakeLists.txt

+cmake_minimum_required(VERSION 2.6)
+
+subdirs(f_fftw)
\ No newline at end of file

f_fftw/f_fftw.cpp

+#include "blc_channel.h"
+#include "blc_program.h"
+#include <fftw3.h>
+#include <unistd.h>
+#include <math.h> //sqrtf
+#include <pthread.h>
+
+#define DEFAULT_OUTPUT_NAME "fourier<pid> or spectrum<pid>"
+
+sem_t *sem_output, *sem_input;
+int i=0;
+struct timeval;
+blc_channel input, output;
+char const *display, *option_record;
+
+int columns_nb=64, rows_nb=16;
+
+FILE *record_file;
+
+void spectrum_loop(int period){
+    size_t i;
+    fftwf_complex *intermediate;
+    fftwf_plan fftw_plan;
+    
+    intermediate=fftwf_alloc_complex(output.total_length);
+    fftw_plan = fftwf_plan_dft_r2c_1d(input.total_length, input.floats, intermediate , FFTW_ESTIMATE);
+    
+    BLC_COMMAND_LOOP(period*1000){
+        fftwf_execute(fftw_plan); /* repeat as needed */
+        FOR(i, output.total_length){
+            output.floats[i]=sqrtf(intermediate[i][0]*intermediate[i][0]+intermediate[i][1]*intermediate[i][1])/output.total_length;
+        }
+        if(display){
+            blc_fprint_float_graph(stderr, output.floats, output.total_length, "spectrum", columns_nb, rows_nb, 1, 0, "Frequency", "Intensity");
+            blc_eprint_cursor_up(rows_nb);
+        }
+        
+        if (record_file)      fprint_tsv_floats(record_file, output.floats, output.total_length);
+    }
+    fftwf_destroy_plan(fftw_plan);
+    blc_eprint_cursor_down(rows_nb);
+    
+}
+
+void standard_loop(int period){
+    fftwf_plan fftw_plan;
+    fftw_plan = fftwf_plan_r2r_1d(input.total_length, input.floats, output.floats , FFTW_R2HC, FFTW_ESTIMATE);
+    
+    BLC_COMMAND_LOOP(period*1000){
+        fftwf_execute(fftw_plan); /* repeat as needed */
+         
+        if(display){
+            blc_fprint_float_graph(stderr, output.floats, output.total_length, "spectrum", columns_nb, rows_nb, 1, 0, "Frequency", "Intensity");
+            blc_eprint_cursor_up(rows_nb);
+        }
+    }
+    fftwf_destroy_plan(fftw_plan);
+    blc_eprint_cursor_down(rows_nb);
+}
+
+int main(int argc, char**argv){
+    char const *input_name, *output_name, *spectrum_option, *period_str;
+    int output_length, period;
+    
+    blc_program_add_option(&output_name, 'o', "output", "string", "Channel containing the fast fourier transformation", DEFAULT_OUTPUT_NAME);
+    blc_program_add_option(&display, 'd', "display", NULL, "Display the result as text graph", NULL);
+    blc_program_add_option(&option_record, 'e', "export", "filename", "export data on file in parameter", NULL);
+    blc_program_add_option(&period_str, 'p', "period", "integer", "Period in ms (0 as fast as possible). No effect if input synchro.", "100");
+    blc_program_add_option(&spectrum_option, 's', "spectrum", NULL, "Get the square value of the fftw signal", NULL);
+    blc_program_add_parameter(&input_name, "input blc_channel", 1, "Channel containing the sound data", NULL);
+    blc_program_init(&argc, &argv, NULL);
+    
+    //Open input channel and check the type of values
+    input.open(input_name, BLC_CHANNEL_READ);
+    
+    if (input.type!='FL32') EXIT_ON_CHANNEL_ERROR(&input,"Input must be of type 'FL32'");
+    
+    if (input.sem_new_data) {
+        period=0; //As fast as possible
+    }
+    else if (sscanf(period_str, "%d", &period)==0) EXIT_ON_ERROR("Interpretting period: '%s'", period_str);
+    
+    if (strcmp(DEFAULT_OUTPUT_NAME, output_name)==0) {
+        if(spectrum_option) asprintf((char**)&output_name, ":spectrum%d", getpid());
+        else asprintf((char**)&output_name, ":fourier%d", getpid());
+    }
+    
+    if (option_record) {
+        SYSTEM_ERROR_CHECK(record_file=fopen(option_record, "w"), NULL, "Problem creating '%s'", option_record);
+        printf("Recording in: '%s'\n", option_record);
+    }
+    
+    
+    //Create a channel or reopen a previous one.
+    if (spectrum_option) output_length=input.total_length/2+1;
+    else output_length=input.total_length;
+    
+    output.create_or_open(output_name, BLC_CHANNEL_WRITE, 'FL32', 'NDEF', 1, output_length);
+    output.publish();
+    
+    blc_loop_try_add_waiting_semaphore(input.sem_new_data);
+    blc_loop_try_add_waiting_semaphore(output.sem_ack_data);
+    
+    blc_loop_try_add_posting_semaphore(input.sem_ack_data);
+    blc_loop_try_add_posting_semaphore(output.sem_new_data);
+
+    
+    //Start the process depending on the fact we use the square of the values (spectrum) or directly the output
+    //We loop at a maximum speed of period micro seconds
+    if (spectrum_option)  spectrum_loop(period);
+    else standard_loop(period);
+    
+    if (record_file) SYSTEM_SUCCESS_CHECK(fclose(record_file), -1, NULL);
+    
+    return EXIT_SUCCESS;
+}
+