Funtion to discretize spikes from vector fomat (time,period) to buffer (list of interpolatd periods)

+# Copyright  ETIS — ENSEA, Université de Cergy-Pontoise, CNRS
+# Author: Arnaud Blanchard  (November 2016)
+# This software is governed by the CeCILL v2.1 license under French law and abiding by the rules of distribution of free software.
+# You can use, modify and/ or redistribute the software under the terms of the CeCILL v2.1 license as circulated by CEA, CNRS and INRIA at the following URL "http://www.cecill.info".
+# As a counterpart to the access to the source code and  rights to copy, modify and redistribute granted by the license,
+# users are provided only with a limited warranty and the software's author, the holder of the economic rights,  and the successive licensors have only limited liability.
+# In this respect, the user's attention is drawn to the risks associated with loading, using, modifying and/or developing or reproducing the software by the user in light of its specific status of free software,
+# that may mean  that it is complicated to manipulate, and that also therefore means that it is reserved for developers and experienced professionals having in-depth computer knowledge.
+# Users are therefore encouraged to load and test the software's suitability as regards their requirements in conditions enabling the security of their systems and/or data to be ensured  and, more generally, to use and operate it in the same conditions as regards security.
+# The fact that you are presently reading this means that you have had knowledge of the CeCILL v2.1 license and that you accept its terms. 
+
+cmake_minimum_required(VERSION 2.6)
+
+project(i_discretize_file)
+
+find_package(blc_channel REQUIRED)
+find_package(blc_program REQUIRED)
+
+add_definitions(${BL_DEFINTIIONS})
+include_directories(${BL_INCLUDE_DIRS})
+add_executable(i_discretize_file i_discretize_file.cpp)
+target_link_libraries(i_discretize_file ${BL_LIBRARIES})
+
+
+
+

+
+
+Read a binary file in form where only columns 2 and 3 are used.  
+        0.        1       	2.        3		
+    <uint32_t><uint32_t><uint32_t><uint32_t>
+	
+
+2 is the absolute timing in µs of a spike, 3 is the period between two spikes.
+
+It generates a buffer of floats 'FL32' in sound format 'LPCM' interpolating the period with a samplerate given in parameter i.e. -S8000 is a samplerate and -s1024 is the size of the buffer.
+-O112 is the offset of the signal to center the signal around 0. -g2.0 is the gain to amplify or decrease the signal.
+
+Exemple of use to listen a sound
+
+    i_discretize_file left_ear.bin -o :sound -s1024 -S8000  -O112 -g2.0 | o_sound.sh -S8000
+	
+In parrallel sound can be dislayed in a graph `o_gnuplot /sound`
+
+We can also diplay the fft transform of the signal:
+
+    i_discretize_file left_ear.bin -o :sound -s2048 -S8000 -O112  | f_fftw_spectrum | o_gnuplot -M1
+
+
+

+# Copyright  ETIS — ENSEA, Université de Cergy-Pontoise, CNRS (2011 - 2016)
+# Author: Arnaud Blanchard (November 2016)
+# This software is governed by the CeCILL v2.1 license under French law and abiding by the rules of distribution of free software.
+# You can use, modify and/ or redistribute the software under the terms of the CeCILL v2.1 license as circulated by CEA, CNRS and INRIA at the following URL "http://www.cecill.info".
+# As a counterpart to the access to the source code and  rights to copy, modify and redistribute granted by the license,
+# users are provided only with a limited warranty and the software's author, the holder of the economic rights,  and the successive licensors have only limited liability.
+# In this respect, the user's attention is drawn to the risks associated with loading, using, modifying and/or developing or reproducing the software by the user in light of its specific status of free software,
+# that may mean  that it is complicated to manipulate, and that also therefore means that it is reserved for developers and experienced professionals having in-depth computer knowledge.
+# Users are therefore encouraged to load and test the software's suitability as regards their requirements in conditions enabling the security of their systems and/or data to be ensured  and, more generally, to use and operate it in the same conditions as regards security.
+# The fact that you are presently reading this means that you have had knowledge of the CeCILL v2.1 license and that you accept its terms.
+
+
+cd `dirname $0`
+echo
+echo "Checking `basename $PWD`"
+echo "===================="
+echo
+echo "No check for now"
+echo 

+//Read only array of dim 1
+#include "blc_core.h"
+#include "blc_channel.h"
+#include "blc_program.h"
+#include <unistd.h>
+#include <termios.h>
+#include <libgen.h> //basename
+
+#define READ_VAR(file, var) read_file(file, (void*)&var, sizeof(var))
+#define WRITE_VAR(file, var) write_file(file, (void*)&var, sizeof(var))
+
+bool read_file(FILE *file, void *data, size_t size){
+    ssize_t ret;
+    ret=fread(data, 1, size, file);
+    if (ret != (ssize_t)size) {
+        if ((ret==0) && feof(file)) return false;
+        else EXIT_ON_SYSTEM_ERROR("Reading file ret: '%d' instead od '%d'", ret, size);
+    }
+    return true;
+}
+
+void write_file(FILE *file, void *data, size_t size){
+    ssize_t ret;
+    ret=fwrite(data, 1, size, file);
+    if (ret != (ssize_t)size) EXIT_ON_SYSTEM_ERROR("Reading file ret: '%d' instead od '%d'", ret, size);
+}
+
+int main(int argc, char** argv){
+    char const *channel_name, *input_filename, *output_filename, *length_str, *samplerate_str, *period_str, *offset_str, *gain_str;
+    char  *default_output;
+    float offset, gain;
+    int number=-1;
+    uint32_t start_load, time_load, start_delay, time_delay;
+    blc_channel channel;
+    FILE *file;
+    int  period, length;
+    int samplerate;
+    
+    asprintf(&default_output, "/%s%d", basename(argv[0]), getpid()); //This will not be free but it is only allocate once
+    blc_program_add_option(&output_filename, 'f', "file", "string", "filename of the file to export", NULL);
+    blc_program_add_option(&gain_str, 'g', "gain", "real", "gain to amplify the signal", "1.0");
+    blc_program_add_option(&channel_name, 'o', "blc_channel-out", "string", "blc_channel to export", default_output);
+    blc_program_add_option(&period_str, 'p', "period", "integer", "items nb in buffer", "0");
+    blc_program_add_option(&length_str, 's', "size", "integer", "items nb in buffer", "1024");
+    blc_program_add_option(&offset_str, 'O', "offset", "real", "offset to remove from the signal", "0");
+    blc_program_add_option(&samplerate_str, 'S', "samplerate", "integer", "samplerate", "8000");
+    blc_program_add_parameter(&input_filename, "filename", 1, "File to load", NULL);
+    blc_program_init(&argc, &argv, blc_quit);
+    blc_command_forward_blc_channels();
+    
+    SSCANF(1, period_str, "%d", &period);
+    SSCANF(1, length_str, "%d", &length);
+    SSCANF(1, samplerate_str, "%d", &samplerate);
+    SSCANF(1, offset_str, "%f", &offset);
+    SSCANF(1, gain_str, "%f", &gain);
+
+    channel.create_or_open(channel_name, BLC_CHANNEL_WRITE, 'FL32', 'LPCM', 1, length);
+    blc_loop_try_add_posting_semaphore(channel.sem_new_data);
+    blc_loop_try_add_waiting_semaphore(channel.sem_ack_data);
+    
+    SYSTEM_ERROR_CHECK(file=fopen(input_filename, "r"), NULL, "Opening '%s'", input_filename);
+    channel.publish();
+    
+    uint32_t iteration=0;
+    float a, b, u, v,result, moy;
+    
+    a=0;
+    u=0;
+    int index;
+    b=0;
+    start_delay=0;
+    iteration=0;
+    moy=0;
+    v=0;
+    BLC_COMMAND_LOOP(period*1000){
+        if (feof(file)){
+            if (number==-1) blc_command_ask_quit();
+            else EXIT_ON_ERROR("End of file and you request '%d' iterations. Only '%d' has been done.", number, blc_loop_iteration);
+        }
+        else{
+            for(index=0; index < channel.total_length; index++){
+                
+                if (b<=iteration){
+                    READ_VAR(file, start_load);
+                    READ_VAR(file, time_load);
+                    READ_VAR(file, start_delay);
+                    READ_VAR(file, time_delay);
+                    a=b;
+                    u=v;
+                    b=(float)start_delay*samplerate/1000000.f;
+                    v=gain*((float)(time_delay)-offset);
+                }
+                //Formule of interpolation
+                result=u+(iteration-a)*(v-u)/(b-a);
+                channel.floats[index]=result;
+                iteration++;
+            }
+        }
+    }
+    SYSTEM_ERROR_CHECK(fclose(file), -1, "Closing '%s'", input_filename);
+    
+    fprintf(stderr, "Stop at %u µs iteration %d",  start_delay, iteration);
+    return EXIT_SUCCESS;
+}