Сжатие данных методом арифметического кодирования

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
 
int main(int argc, char *argv[])
{
 
  FILE *in_f, *out_f, *log_f;
  float table[256][2];
  int i,
      char_count = 0;
  char buff      = 0;
  unsigned int new_low,
               new_high,
               old_low = 0,
               old_high = 9999;
  float char_low, char_high;
  int temp;
 
  const char *str = (char*)malloc(1);
  int code;
  float index;
  int finish=0;
 
  /* Cleaning table*/
  for (i = 0; i < 256; i++)
    {
         table[i][0] = 0;
         table[i][1] = 0;
    }
 
  /*checking the parameters amount*/
  if (argc!=4)
  {
    printf("Input error #1!!!%d\n", argc);
    return 0;
  }
 
  /*Checking the 1st parameter*/
  if (strcmp("-c", argv[1])!=0 && strcmp("-d", argv[1])!=0)
  {
    printf("Input error #2!!!\n");
    return 0;
  }
 
/*  CODING BLOCK   */
 
if (strcmp("-c", argv[1])==0)
{
 
  /* Trying to open the file for reading*/
  if (!(in_f = fopen(argv[2], "rb")))
  {
    printf("Input error #3!!!\n");
    return 0;
  }
 
  out_f = fopen(argv[3], "w");
  log_f = fopen("log_file.log", "w");
 
 
/* Reading characters from file*/
  while (fread(&buff, sizeof(char), 1, in_f )==1)
  {
    table[buff][0] +=1;
    char_count +=1;
  }
  rewind(in_f);
 
/* Calculating percentage */
  for (i = 0; i < 256; i++)
  {
         if (i!=0) table[i][1] = table[i][0] / char_count + table[i-1][1];
         else table[i][1] = table[i][0] / char_count;
 
         if (table[i][0]!=0) fprintf(log_f,"character %3d - %c amount %5.0f high range %f\n", i, i, table[i][0], table[i][1]);
  }
 
  fprintf(log_f, "low %d high %d\n", old_low, old_high); /*  Writing to LOG file  */
 
  /* Coding the file */
  while (fread(&buff, sizeof(char), 1, in_f )==1)
  {
        if (buff!=0)                     // getting character low range
          char_low = table[buff-1][1];
        else char_low = 0;
        char_high = table[buff][1];      // getting character high range
 
        new_low = old_low + (old_high+1-old_low)*char_low;     // calculating
        new_high = old_low + (old_high+1-old_low)*char_high-1; // new low and high
        fprintf(log_f, "low %d high %d\n", new_low, new_high); /*  Writing to LOG file  */
 
        /* Writing the first character to the output file */
        while (new_low/1000 == new_high/1000)
        {
          buff = (char) (new_low/1000)+48;     // getting the first digit
          fprintf(log_f,">> writing to out_file %c\n", buff);
          fprintf(out_f,"%c", buff);
          temp = floor(new_low/1000);
          new_low = (new_low - temp*1000)*10;   // new low and high
          new_high = (new_high - temp*1000)*10+9;
          fprintf(log_f, "!! new low %d new high %d\n", new_low, new_high);
        }
 
        old_low = new_low;
        old_high = new_high;
 
  }
  fprintf(out_f, "%d\n", new_low);
 
/* writing table to the out file*/
for (i = 0; i< 255; i++)
    if (table[i][0]!=0) fprintf(out_f, "%d %.0f\n", i, table[i][0]);
printf ("Done");
}  /* THE END OF CODING BLOCK*/
 
 
/*-----------------*/
/*  DECODING BLOCK */
/*-----------------*/
 
if (strcmp(argv[1],"-d")==0)
{
  /* trying to open file */
  if (!(in_f = fopen(argv[2], "r")))
  {
    printf("Input error #3!!!\n");
    return 0;
  }
  out_f = fopen(argv[3], "w");
  log_f = fopen("log_file.log", "w");
 
/* READING THE CODE */
temp = fgetc(in_f);
char_count +=1; // amount of characters in the codeString
while (temp!='\n')
{
       str = realloc(str, char_count*sizeof(char)+1);
       strcat(str, &temp);
       temp = fgetc(in_f);
       char_count +=1;
}
     fprintf(log_f, "Full CodeString - %s\n", str);
     sscanf(str, "%4d%s", &code, str);
     fprintf(log_f, "Code int - %d\n", code);
     fprintf(log_f, "Truncated CodeString - %s\n", str);
/* END OF CODE READING */
 
/* FILLING THE TABLE */
  char_count = 0;  // amount of characters to be decoded
  while (!feof(in_f))
  {
      fscanf(in_f, "%d %d\n", &i, &temp);
      table[i][0] = temp;
      char_count += temp;
  }
/* END OF TABLE FILLING */
 
/* CALCULATING PERCENTAGE */
  for (i = 0; i < 256; i++)
  {
         if (i!=0) table[i][1] = table[i][0] / char_count + table[i-1][1];
         else table[i][1] = table[i][0] / char_count;
 
         if (table[i][0]!=0) fprintf(log_f,"Character %3d - %c amount %5.0f high range %f\n", i, i, table[i][0], table[i][1]);
  }
/* END OF CALCULATING PERCENTAGE */
 
/* DECODING */
 
      index = (float)(code-old_low)/(old_high-old_low+1);
      fprintf(log_f, "Index - %f\n", index);
 
do
{
   for (i = 0; i < 256; i++)
//   if (table[i][0]>0)   // if there is at least one such character...
   {
        /* Getting High and Low ranges of the character */
        if (i>0) char_low = table[i-1][1];
        else char_low = 0;
        char_high = table[i][1];
        //printf ("%d %d %d", char_low, index, char_high);
         if ((char_high > index) && (char_low <= index))
         {
           fprintf(out_f, "%c", i);
           fprintf(log_f, "%c found\n", i);
           printf("%c found\n", i);
           char_count -=1;
           printf("char count %d\n", char_count);
           table[i][0] -=1;                  // 1 char is found, amount-1 is left
 
           new_low = old_low+(old_high+1-old_low)*char_low;
           new_high = old_low+(old_high+1-old_low)*char_high-1;
           old_low = new_low;
           old_high = new_high;
/*
           index = (float)(code-old_low)/(old_high-old_low+1);
           fprintf(log_f, "New low - %d New high - %d\nIndex - %f\n", new_low, new_high, index);
           printf("New low - %d New high - %d\nIndex - %f\n", new_low, new_high, index);
*/
           /* changing the code */
           while (new_low/1000 == new_high/1000)
           {
             fprintf(log_f, "Low and High Match is reached\n");
             printf("Low and High Match is reached\n");
 
             new_low = new_low % 1000*10;
             new_high =new_high%1000*10+9;
             old_low = new_low;
             old_high = new_high;
             fprintf(log_f, "!! new low %d new high %d\n", new_low, new_high);
             printf("!! new low %d new high %d\n", new_low, new_high);
 
             sscanf(str, "%1d%s", &temp, str);
             code = code % 1000 * 10 + temp;
             fprintf(log_f,"New code - %d, New string - %s\n", code, str);
           } /* end of While (new_low/1000 == new_high/1000) */
           printf ("code - %d\n", code);
           index = (float)(code-old_low)/(old_high-old_low+1);
           fprintf(log_f, "New low - %d New high - %d\nIndex - %f\n", new_low, new_high, index);
           printf(" --> New low - %d New high - %d\nIndex - %f\n", new_low, new_high, index);
 
          }  /* end of if (char_high > index && char_low < index) */
   }
}
//while (strlen(str)!=0);
while (char_count!=0);
 
    free(str);
    printf("Done");
}
/* THE END OF DECODING BLOCK */
 
  fclose(in_f);
  fclose(out_f);
  fclose(log_f);
  return 0;
}