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      1 /*
      2  *  pnm2png.c --- conversion from PBM/PGM/PPM-file to PNG-file
      3  *  copyright (C) 1999 by Willem van Schaik <willem (at) schaik.com>
      4  *
      5  *  version 1.0 - 1999.10.15 - First version.
      6  *  version 1.1 - 2015.07.29 - Fixed leaks (Glenn Randers-Pehrson)
      7  *
      8  *  Permission to use, copy, modify, and distribute this software and
      9  *  its documentation for any purpose and without fee is hereby granted,
     10  *  provided that the above copyright notice appear in all copies and
     11  *  that both that copyright notice and this permission notice appear in
     12  *  supporting documentation. This software is provided "as is" without
     13  *  express or implied warranty.
     14  */
     15 
     16 #include <stdio.h>
     17 #include <stdlib.h>
     18 #ifdef __TURBOC__
     19 #include <mem.h>
     20 #include <fcntl.h>
     21 #endif
     22 #include <zlib.h>
     23 
     24 #ifndef BOOL
     25 #define BOOL unsigned char
     26 #endif
     27 #ifndef TRUE
     28 #define TRUE (BOOL) 1
     29 #endif
     30 #ifndef FALSE
     31 #define FALSE (BOOL) 0
     32 #endif
     33 
     34 #define STDIN  0
     35 #define STDOUT 1
     36 #define STDERR 2
     37 
     38 /* to make pnm2png verbose so we can find problems (needs to be before png.h) */
     39 #ifndef PNG_DEBUG
     40 #define PNG_DEBUG 0
     41 #endif
     42 
     43 #include "png.h"
     44 
     45 /* Define png_jmpbuf() in case we are using a pre-1.0.6 version of libpng */
     46 #ifndef png_jmpbuf
     47 #  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
     48 #endif
     49 
     50 /* function prototypes */
     51 
     52 int  main (int argc, char *argv[]);
     53 void usage ();
     54 BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
     55     BOOL alpha);
     56 void get_token(FILE *pnm_file, char *token);
     57 png_uint_32 get_data (FILE *pnm_file, int depth);
     58 png_uint_32 get_value (FILE *pnm_file, int depth);
     59 
     60 /*
     61  *  main
     62  */
     63 
     64 int main(int argc, char *argv[])
     65 {
     66   FILE *fp_rd = stdin;
     67   FILE *fp_al = NULL;
     68   FILE *fp_wr = stdout;
     69   BOOL interlace = FALSE;
     70   BOOL alpha = FALSE;
     71   int argi;
     72 
     73   for (argi = 1; argi < argc; argi++)
     74   {
     75     if (argv[argi][0] == '-')
     76     {
     77       switch (argv[argi][1])
     78       {
     79         case 'i':
     80           interlace = TRUE;
     81           break;
     82         case 'a':
     83           alpha = TRUE;
     84           argi++;
     85           if ((fp_al = fopen (argv[argi], "rb")) == NULL)
     86           {
     87             fprintf (stderr, "PNM2PNG\n");
     88             fprintf (stderr, "Error:  alpha-channel file %s does not exist\n",
     89                argv[argi]);
     90             exit (1);
     91           }
     92           break;
     93         case 'h':
     94         case '?':
     95           usage();
     96           exit(0);
     97           break;
     98         default:
     99           fprintf (stderr, "PNM2PNG\n");
    100           fprintf (stderr, "Error:  unknown option %s\n", argv[argi]);
    101           usage();
    102           exit(1);
    103           break;
    104       } /* end switch */
    105     }
    106     else if (fp_rd == stdin)
    107     {
    108       if ((fp_rd = fopen (argv[argi], "rb")) == NULL)
    109       {
    110         fprintf (stderr, "PNM2PNG\n");
    111         fprintf (stderr, "Error:  file %s does not exist\n", argv[argi]);
    112         exit (1);
    113       }
    114     }
    115     else if (fp_wr == stdout)
    116     {
    117       if ((fp_wr = fopen (argv[argi], "wb")) == NULL)
    118       {
    119         fprintf (stderr, "PNM2PNG\n");
    120         fprintf (stderr, "Error:  can not create PNG-file %s\n", argv[argi]);
    121         exit (1);
    122       }
    123     }
    124     else
    125     {
    126       fprintf (stderr, "PNM2PNG\n");
    127       fprintf (stderr, "Error:  too many parameters\n");
    128       usage();
    129       exit (1);
    130     }
    131   } /* end for */
    132 
    133 #ifdef __TURBOC__
    134   /* set stdin/stdout to binary, we're reading the PNM always! in binary format */
    135   if (fp_rd == stdin)
    136   {
    137     setmode (STDIN, O_BINARY);
    138   }
    139   if (fp_wr == stdout)
    140   {
    141     setmode (STDOUT, O_BINARY);
    142   }
    143 #endif
    144 
    145   /* call the conversion program itself */
    146   if (pnm2png (fp_rd, fp_wr, fp_al, interlace, alpha) == FALSE)
    147   {
    148     fprintf (stderr, "PNM2PNG\n");
    149     fprintf (stderr, "Error:  unsuccessful converting to PNG-image\n");
    150     exit (1);
    151   }
    152 
    153   /* close input file */
    154   fclose (fp_rd);
    155   /* close output file */
    156   fclose (fp_wr);
    157   /* close alpha file */
    158   if (alpha)
    159     fclose (fp_al);
    160 
    161   return 0;
    162 }
    163 
    164 /*
    165  *  usage
    166  */
    167 
    168 void usage()
    169 {
    170   fprintf (stderr, "PNM2PNG\n");
    171   fprintf (stderr, "   by Willem van Schaik, 1999\n");
    172 #ifdef __TURBOC__
    173   fprintf (stderr, "   for Turbo-C and Borland-C compilers\n");
    174 #else
    175   fprintf (stderr, "   for Linux (and Unix) compilers\n");
    176 #endif
    177   fprintf (stderr, "Usage:  pnm2png [options] <file>.<pnm> [<file>.png]\n");
    178   fprintf (stderr, "   or:  ... | pnm2png [options]\n");
    179   fprintf (stderr, "Options:\n");
    180   fprintf (stderr, "   -i[nterlace]   write png-file with interlacing on\n");
    181   fprintf (stderr,
    182       "   -a[lpha] <file>.pgm read PNG alpha channel as pgm-file\n");
    183   fprintf (stderr, "   -h | -?  print this help-information\n");
    184 }
    185 
    186 /*
    187  *  pnm2png
    188  */
    189 
    190 BOOL pnm2png (FILE *pnm_file, FILE *png_file, FILE *alpha_file, BOOL interlace,
    191      BOOL alpha)
    192 {
    193   png_struct    *png_ptr = NULL;
    194   png_info      *info_ptr = NULL;
    195   png_byte      *png_pixels = NULL;
    196   png_byte      **row_pointers = NULL;
    197   png_byte      *pix_ptr = NULL;
    198   volatile png_uint_32   row_bytes;
    199 
    200   char          type_token[16];
    201   char          width_token[16];
    202   char          height_token[16];
    203   char          maxval_token[16];
    204   volatile int    color_type=1;
    205   unsigned long   ul_width=0, ul_alpha_width=0;
    206   unsigned long   ul_height=0, ul_alpha_height=0;
    207   unsigned long   ul_maxval=0;
    208   volatile png_uint_32   width=0, height=0;
    209   volatile png_uint_32   alpha_width=0, alpha_height=0;
    210   png_uint_32   maxval;
    211   volatile int           bit_depth = 0;
    212   int           channels=0;
    213   int           alpha_depth = 0;
    214   int           alpha_present=0;
    215   int           row, col;
    216   BOOL          raw, alpha_raw = FALSE;
    217 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
    218   BOOL          packed_bitmap = FALSE;
    219 #endif
    220   png_uint_32   tmp16;
    221   int           i;
    222 
    223   /* read header of PNM file */
    224 
    225   get_token(pnm_file, type_token);
    226   if (type_token[0] != 'P')
    227   {
    228     return FALSE;
    229   }
    230   else if ((type_token[1] == '1') || (type_token[1] == '4'))
    231   {
    232 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
    233     raw = (type_token[1] == '4');
    234     color_type = PNG_COLOR_TYPE_GRAY;
    235     get_token(pnm_file, width_token);
    236     sscanf (width_token, "%lu", &ul_width);
    237     width = (png_uint_32) ul_width;
    238     get_token(pnm_file, height_token);
    239     sscanf (height_token, "%lu", &ul_height);
    240     height = (png_uint_32) ul_height;
    241     bit_depth = 1;
    242     packed_bitmap = TRUE;
    243 #else
    244     fprintf (stderr, "PNM2PNG built without PNG_WRITE_INVERT_SUPPORTED and \n");
    245     fprintf (stderr, "PNG_WRITE_PACK_SUPPORTED can't read PBM (P1,P4) files\n");
    246 #endif
    247   }
    248   else if ((type_token[1] == '2') || (type_token[1] == '5'))
    249   {
    250     raw = (type_token[1] == '5');
    251     color_type = PNG_COLOR_TYPE_GRAY;
    252     get_token(pnm_file, width_token);
    253     sscanf (width_token, "%lu", &ul_width);
    254     width = (png_uint_32) ul_width;
    255     get_token(pnm_file, height_token);
    256     sscanf (height_token, "%lu", &ul_height);
    257     height = (png_uint_32) ul_height;
    258     get_token(pnm_file, maxval_token);
    259     sscanf (maxval_token, "%lu", &ul_maxval);
    260     maxval = (png_uint_32) ul_maxval;
    261 
    262     if (maxval <= 1)
    263       bit_depth = 1;
    264     else if (maxval <= 3)
    265       bit_depth = 2;
    266     else if (maxval <= 15)
    267       bit_depth = 4;
    268     else if (maxval <= 255)
    269       bit_depth = 8;
    270     else /* if (maxval <= 65535) */
    271       bit_depth = 16;
    272   }
    273   else if ((type_token[1] == '3') || (type_token[1] == '6'))
    274   {
    275     raw = (type_token[1] == '6');
    276     color_type = PNG_COLOR_TYPE_RGB;
    277     get_token(pnm_file, width_token);
    278     sscanf (width_token, "%lu", &ul_width);
    279     width = (png_uint_32) ul_width;
    280     get_token(pnm_file, height_token);
    281     sscanf (height_token, "%lu", &ul_height);
    282     height = (png_uint_32) ul_height;
    283     get_token(pnm_file, maxval_token);
    284     sscanf (maxval_token, "%lu", &ul_maxval);
    285     maxval = (png_uint_32) ul_maxval;
    286     if (maxval <= 1)
    287       bit_depth = 1;
    288     else if (maxval <= 3)
    289       bit_depth = 2;
    290     else if (maxval <= 15)
    291       bit_depth = 4;
    292     else if (maxval <= 255)
    293       bit_depth = 8;
    294     else /* if (maxval <= 65535) */
    295       bit_depth = 16;
    296   }
    297   else
    298   {
    299     return FALSE;
    300   }
    301 
    302   /* read header of PGM file with alpha channel */
    303 
    304   if (alpha)
    305   {
    306     if (color_type == PNG_COLOR_TYPE_GRAY)
    307       color_type = PNG_COLOR_TYPE_GRAY_ALPHA;
    308     if (color_type == PNG_COLOR_TYPE_RGB)
    309       color_type = PNG_COLOR_TYPE_RGB_ALPHA;
    310 
    311     get_token(alpha_file, type_token);
    312     if (type_token[0] != 'P')
    313     {
    314       return FALSE;
    315     }
    316     else if ((type_token[1] == '2') || (type_token[1] == '5'))
    317     {
    318       alpha_raw = (type_token[1] == '5');
    319       get_token(alpha_file, width_token);
    320       sscanf (width_token, "%lu", &ul_alpha_width);
    321       alpha_width=(png_uint_32) ul_alpha_width;
    322       if (alpha_width != width)
    323         return FALSE;
    324       get_token(alpha_file, height_token);
    325       sscanf (height_token, "%lu", &ul_alpha_height);
    326       alpha_height = (png_uint_32) ul_alpha_height;
    327       if (alpha_height != height)
    328         return FALSE;
    329       get_token(alpha_file, maxval_token);
    330       sscanf (maxval_token, "%lu", &ul_maxval);
    331       maxval = (png_uint_32) ul_maxval;
    332       if (maxval <= 1)
    333         alpha_depth = 1;
    334       else if (maxval <= 3)
    335         alpha_depth = 2;
    336       else if (maxval <= 15)
    337         alpha_depth = 4;
    338       else if (maxval <= 255)
    339         alpha_depth = 8;
    340       else /* if (maxval <= 65535) */
    341         alpha_depth = 16;
    342       if (alpha_depth != bit_depth)
    343         return FALSE;
    344     }
    345     else
    346     {
    347       return FALSE;
    348     }
    349   } /* end if alpha */
    350 
    351   /* calculate the number of channels and store alpha-presence */
    352   if (color_type == PNG_COLOR_TYPE_GRAY)
    353     channels = 1;
    354   else if (color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
    355     channels = 2;
    356   else if (color_type == PNG_COLOR_TYPE_RGB)
    357     channels = 3;
    358   else if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)
    359     channels = 4;
    360 #if 0
    361   else
    362     channels = 0; /* cannot happen */
    363 #endif
    364 
    365   alpha_present = (channels - 1) % 2;
    366 
    367 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
    368   if (packed_bitmap)
    369     /* row data is as many bytes as can fit width x channels x bit_depth */
    370     row_bytes = (width * channels * bit_depth + 7) / 8;
    371   else
    372 #endif
    373     /* row_bytes is the width x number of channels x (bit-depth / 8) */
    374     row_bytes = width * channels * ((bit_depth <= 8) ? 1 : 2);
    375 
    376   if ((png_pixels = (png_byte *)
    377      malloc (row_bytes * height * sizeof (png_byte))) == NULL)
    378     return FALSE;
    379 
    380   /* read data from PNM file */
    381   pix_ptr = png_pixels;
    382 
    383   for (row = 0; row < (int) height; row++)
    384   {
    385 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
    386     if (packed_bitmap) {
    387       for (i = 0; i < (int) row_bytes; i++)
    388         /* png supports this format natively so no conversion is needed */
    389         *pix_ptr++ = get_data (pnm_file, 8);
    390     } else
    391 #endif
    392     {
    393       for (col = 0; col < (int) width; col++)
    394       {
    395         for (i = 0; i < (channels - alpha_present); i++)
    396         {
    397           if (raw)
    398             *pix_ptr++ = get_data (pnm_file, bit_depth);
    399           else
    400             if (bit_depth <= 8)
    401               *pix_ptr++ = get_value (pnm_file, bit_depth);
    402             else
    403             {
    404               tmp16 = get_value (pnm_file, bit_depth);
    405               *pix_ptr = (png_byte) ((tmp16 >> 8) & 0xFF);
    406               pix_ptr++;
    407               *pix_ptr = (png_byte) (tmp16 & 0xFF);
    408               pix_ptr++;
    409             }
    410         }
    411 
    412         if (alpha) /* read alpha-channel from pgm file */
    413         {
    414           if (alpha_raw)
    415             *pix_ptr++ = get_data (alpha_file, alpha_depth);
    416           else
    417             if (alpha_depth <= 8)
    418               *pix_ptr++ = get_value (alpha_file, bit_depth);
    419             else
    420             {
    421               tmp16 = get_value (alpha_file, bit_depth);
    422               *pix_ptr++ = (png_byte) ((tmp16 >> 8) & 0xFF);
    423               *pix_ptr++ = (png_byte) (tmp16 & 0xFF);
    424             }
    425         } /* if alpha */
    426       } /* if packed_bitmap */
    427     } /* end for col */
    428   } /* end for row */
    429 
    430   /* prepare the standard PNG structures */
    431   png_ptr = png_create_write_struct (png_get_libpng_ver(NULL), NULL, NULL,
    432       NULL);
    433   if (!png_ptr)
    434   {
    435     free (png_pixels);
    436     png_pixels = NULL;
    437     return FALSE;
    438   }
    439   info_ptr = png_create_info_struct (png_ptr);
    440   if (!info_ptr)
    441   {
    442     png_destroy_write_struct (&png_ptr, (png_infopp) NULL);
    443     free (png_pixels);
    444     png_pixels = NULL;
    445     return FALSE;
    446   }
    447 
    448 #if defined(PNG_WRITE_INVERT_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED)
    449   if (packed_bitmap == TRUE)
    450   {
    451     png_set_packing (png_ptr);
    452     png_set_invert_mono (png_ptr);
    453   }
    454 #endif
    455 
    456   /* setjmp() must be called in every function that calls a PNG-reading libpng function */
    457   if (setjmp (png_jmpbuf(png_ptr)))
    458   {
    459     png_destroy_write_struct (&png_ptr, &info_ptr);
    460     free (png_pixels);
    461     png_pixels = NULL;
    462     return FALSE;
    463   }
    464 
    465   /* initialize the png structure */
    466   png_init_io (png_ptr, png_file);
    467 
    468   /* we're going to write more or less the same PNG as the input file */
    469   png_set_IHDR (png_ptr, info_ptr, width, height, bit_depth, color_type,
    470     (!interlace) ? PNG_INTERLACE_NONE : PNG_INTERLACE_ADAM7,
    471     PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
    472 
    473   /* write the file header information */
    474   png_write_info (png_ptr, info_ptr);
    475 
    476   /* if needed we will allocate memory for an new array of row-pointers */
    477   if (row_pointers == (unsigned char**) NULL)
    478   {
    479     if ((row_pointers = (png_byte **)
    480         malloc (height * sizeof (png_bytep))) == NULL)
    481     {
    482       png_destroy_write_struct (&png_ptr, &info_ptr);
    483       free (png_pixels);
    484       png_pixels = NULL;
    485       return FALSE;
    486     }
    487   }
    488 
    489   /* set the individual row_pointers to point at the correct offsets */
    490   for (i = 0; i < (int) height; i++)
    491     row_pointers[i] = png_pixels + i * row_bytes;
    492 
    493   /* write out the entire image data in one call */
    494   png_write_image (png_ptr, row_pointers);
    495 
    496   /* write the additional chunks to the PNG file (not really needed) */
    497   png_write_end (png_ptr, info_ptr);
    498 
    499   /* clean up after the write, and free any memory allocated */
    500   png_destroy_write_struct (&png_ptr, &info_ptr);
    501 
    502   if (row_pointers != (unsigned char**) NULL)
    503     free (row_pointers);
    504   if (png_pixels != (unsigned char*) NULL)
    505     free (png_pixels);
    506 
    507   return TRUE;
    508 } /* end of pnm2png */
    509 
    510 /*
    511  * get_token() - gets the first string after whitespace
    512  */
    513 
    514 void get_token(FILE *pnm_file, char *token)
    515 {
    516   int i = 0;
    517   int ret;
    518 
    519   /* remove white-space and comment lines */
    520   do
    521   {
    522     ret = fgetc(pnm_file);
    523     if (ret == '#') {
    524       /* the rest of this line is a comment */
    525       do
    526       {
    527         ret = fgetc(pnm_file);
    528       }
    529       while ((ret != '\n') && (ret != '\r') && (ret != EOF));
    530     }
    531     if (ret == EOF) break;
    532     token[i] = (unsigned char) ret;
    533   }
    534   while ((token[i] == '\n') || (token[i] == '\r') || (token[i] == ' '));
    535 
    536   /* read string */
    537   do
    538   {
    539     ret = fgetc(pnm_file);
    540     if (ret == EOF) break;
    541     i++;
    542     token[i] = (unsigned char) ret;
    543   }
    544   while ((token[i] != '\n') && (token[i] != '\r') && (token[i] != ' '));
    545 
    546   token[i] = '\0';
    547 
    548   return;
    549 }
    550 
    551 /*
    552  * get_data() - takes first byte and converts into next pixel value,
    553  *        taking as much bits as defined by bit-depth and
    554  *        using the bit-depth to fill up a byte (0Ah -> AAh)
    555  */
    556 
    557 png_uint_32 get_data (FILE *pnm_file, int depth)
    558 {
    559   static int bits_left = 0;
    560   static int old_value = 0;
    561   static int mask = 0;
    562   int i;
    563   png_uint_32 ret_value;
    564 
    565   if (mask == 0)
    566     for (i = 0; i < depth; i++)
    567       mask = (mask >> 1) | 0x80;
    568 
    569   if (bits_left <= 0)
    570   {
    571     old_value = fgetc (pnm_file);
    572     bits_left = 8;
    573   }
    574 
    575   ret_value = old_value & mask;
    576   for (i = 1; i < (8 / depth); i++)
    577     ret_value = ret_value || (ret_value >> depth);
    578 
    579   old_value = (old_value << depth) & 0xFF;
    580   bits_left -= depth;
    581 
    582   return ret_value;
    583 }
    584 
    585 /*
    586  * get_value() - takes first (numeric) string and converts into number,
    587  *         using the bit-depth to fill up a byte (0Ah -> AAh)
    588  */
    589 
    590 png_uint_32 get_value (FILE *pnm_file, int depth)
    591 {
    592   static png_uint_32 mask = 0;
    593   png_byte token[16];
    594   unsigned long ul_ret_value;
    595   png_uint_32 ret_value;
    596   int i = 0;
    597 
    598   if (mask == 0)
    599     for (i = 0; i < depth; i++)
    600       mask = (mask << 1) | 0x01;
    601 
    602   get_token (pnm_file, (char *) token);
    603   sscanf ((const char *) token, "%lu", &ul_ret_value);
    604   ret_value = (png_uint_32) ul_ret_value;
    605 
    606   ret_value &= mask;
    607 
    608   if (depth < 8)
    609     for (i = 0; i < (8 / depth); i++)
    610       ret_value = (ret_value << depth) || ret_value;
    611 
    612   return ret_value;
    613 }
    614 
    615 /* end of source */
    616 
    617