examples/ppmc/unppmc.c

   1 /*
   2    Copyright (C) Arturo San Emeterio Campos 1999. All rights reserved.
   3    Permission is granted to make verbatim copies of this program for private
   4    use only. There is ABSOLUTELY NO WARRANTY. Use it at your OWN RISK.
   5
   6    This file is: "unppmc.c"
   7 Email: arturo@arturocampos.com
   8 Web: http://www.arturocampos.com
   9
  10
  11 Part of the ppmc decoder.
  12
  13 This module is the main module and calls the different modules to do
  14 the decoding of a file. When done prints kbyps.
  15 */
  16
  17
  18 // Bibliotecas necesarias
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include "range.h"      //the range coder functions and data
  22 #include "ppmcdata.h"
  23
  24
  25 // Declaracion de funciones del ppmcmain.c
  26 long filesize(FILE *stream);
  27
  28
  29
  30
  31 //Main
  32 void main (int argc, char *argv[])
  33 {
  34         unsigned long counter, //temporal counter for loops like for or while
  35                       counter2,     //another temporal counter for sub loops
  36                       size_file_output,     //the size of the output file
  37                       main_counter;         //used in main
  38         char expected_flush=0; //used for checking flushing which can't be done
  39
  40
  41         // Print title, version and copyright
  42         printf("UNPPMC using range coder.\n");
  43         printf("Copyright (C) Arturo San Emeterio Campos 1999. All rights reserved.\n");
  44         printf("Permission is granted to make verbatim copies of this program for private\n");
  45         printf("use only. There is ABSOLUTELY NO WARRANTY. Use it at your OWN RISK.\n");
  46
  47
  48
  49         // Check for correct number of parameters
  50         if(argc!=3)
  51         {
  52                 printf("Bad number of arguments.\n");
  53                 exit(1);
  54         }
  55
  56
  57         // Try to open input and output files
  58         if((file_input=fopen(argv[1],"r+b"))==NULL)
  59         {
  60                 printf("Couldn't open %s.\n",argv[1]);
  61                 exit(1);
  62         }
  63
  64         if((file_output=fopen(argv[2],"w+b"))==NULL)
  65         {
  66                 printf("Couldn't create %s.\n",argv[2]);
  67                 exit(1);
  68         }
  69
  70
  71         // Get output length
  72         fread(&size_file_output,1,4,file_input);
  73
  74
  75         // Initialize ppmc decoder
  76         ppmc_alloc_memory();
  77         ppmc_initialize_contexts();
  78         ppmc_decoder_initialize();
  79
  80
  81
  82         // Initialize decoder
  83         range_decoder_init(&rc_decoder,file_input);
  84
  85
  86         // Start main loop which decodes the file
  87         main_counter=size_file_output-4; //take in account the bytes already written
  88         expected_flush=0;                //we don't expect a flush yet
  89
  90         while(main_counter!=0)
  91         {
  92
  93                 // Try to decode current byte in order-4 if possible, else in lower ones
  94                 ppmc_decode_order4();
  95                 if(byte==-1)
  96                         ppmc_decode_order3();
  97                 if(byte==-1)
  98                 {
  99                         ppmc_decode_order2();
 100                         if(byte==-1)
 101                         {
 102                                 ppmc_decode_order1();
 103                                 if(byte==-1)
 104                                 {
 105                                         ppmc_decode_order0();
 106                                         if(byte==-1)         //check if it was an escape code
 107                                         {
 108                                                 // Decode in order-(-1)
 109                                                 ppmc_get_totf_ordern1();
 110                                                 symb_cump=range_decoder_decode(&rc_decoder,total_cump);
 111                                                 byte=ppmc_get_symbol_ordern1();
 112                                                 ppmc_get_prob_ordern1();
 113                                                 range_decoder_update(&rc_decoder,total_cump,symb_cump,symb_prob);
 114                                                 coded_in_order=0;  //update all orders
 115
 116                                                 // Now see if it's the code of flushing
 117
 118                                                 if(symb_cump==256)
 119                                                 {
 120                                                         printf("Flushing.\n");
 121                                                         ppmc_flush_mem_dec();
 122                                                         expected_flush=0;
 123                                                         continue;            //do not output byte nor update
 124                                                 }
 125
 126                                         }
 127                                 }
 128                         }
 129                 }
 130
 131                 // Output byte and update model
 132
 133                 fputc(byte,file_output);
 134
 135                 switch(coded_in_order) //update exclusion
 136                 {
 137                         case 0: ppmc_update_order0();        //update only order-0
 138                         case 1: ppmc_update_order1();        //update order-0 and order-1
 139                         case 2: ppmc_update_dec_order2();    //update order-0 1 and 2
 140                         case 3: ppmc_update_dec_order3();
 141                         case 4: ppmc_update_dec_order4();
 142                         default: break;
 143                 };
 144
 145
 146                 // Check if flushing has to be done and has not been done.
 147                 // This is optional, in case you limit the memory usage, you don't
 148                 // need to include this
 149
 150                 if(expected_flush==1)  // If flushing didn't happen, we can't decode
 151                 {
 152                         printf("Can't decompress file. Not enough memory.\nTry in a machine with more memory.\n");
 153                         exit(1);
 154                 }
 155                 if(ppmc_out_of_memory==1)
 156                 {
 157                         expected_flush=1;    // Next code must be a flush code, otherwise we don't
 158                         // have enough memory, and therefore we can't decode
 159                 }
 160
 161
 162                 // Update order variables
 163
 164                 o4_byte=o3_byte;
 165                 o3_byte=o2_byte;
 166                 o2_byte=o1_byte;
 167                 o1_byte=byte;  //current one, is next time order-1
 168
 169                 // Byte decoded and model updated, loop
 170                 main_counter--;
 171
 172
 173         }
 174
 175
 176         ppmc_free_memory();
 177
 178         // Close file handles and free memory
 179         fclose(file_input);
 180         fclose(file_output);
 181
 182
 183         // Nicely exit
 184         exit(0);
 185 }
 186
 187
 188 // Ruotines not used by ppmc but rather by main.
 189 // Not including the range coder.
 190
 191
 192 // Returns the file size of a given file.
 193 long filesize(FILE *stream)
 194 {
 195         long curpos, length;
 196
 197         curpos = ftell(stream);
 198         fseek(stream, 0L, SEEK_END);
 199         length = ftell(stream);
 200         fseek(stream, curpos, SEEK_SET);
 201         return length;
 202 }
 203
 204