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/* escp2topbm.c - read an Epson ESC/P2 printer file and
** create a pbm file from the raster data,
** ignoring all other data.
** Can be regarded as a simple raster printer emulator
** with a RLE run length decoder.
** This program was made primarily for the test of pbmtoescp2
**
** Copyright (C) 2003 by Ulrich Walcher (u.walcher@gmx.de)
** and Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation. This software is provided "as is" without express or
** implied warranty.
*/
#include <string.h>
#include "pbm.h"
#include "mallocvar.h"
/* RLE decoder */
static unsigned int
dec_epson_rle(unsigned const int k,
unsigned const char * in,
unsigned char * const out) {
unsigned int i;
unsigned int pos;
unsigned int dpos;
pos = 0; /* initial value */
dpos = 0; /* initial value */
while (dpos < k) {
if (in[pos] < 128) {
for (i = 0; i < in[pos] + 1; ++i)
out[dpos+i] = in[pos + i + 1];
/* copy through */
pos += i + 1;
} else {
for (i = 0; i < 257 - in[pos]; ++i)
out[dpos + i] = in[pos + 1];
/* inflate this run */
pos += 2;
}
dpos += i;
}
if(dpos > k)
pm_error("Corrupt compressed block");
return pos; /* return number of treated input bytes */
}
int
main(int argc,
char * argv[]) {
unsigned int const size = 4096; /* arbitrary value */
FILE *ifP;
unsigned int i, len, pos, opos, width, height;
unsigned char *input, *output;
const char * fileName;
pbm_init(&argc, argv);
MALLOCARRAY(input, size);
MALLOCARRAY(output, size);
if (input == NULL || output == NULL)
pm_error("Cannot allocate memory");
if (argc-1 > 1)
pm_error("Too many arguments (%u). Only argument is filename.",
argc-1);
if (argc == 2)
fileName = argv[1];
else
fileName = "-";
ifP = pm_openr(fileName);
/* read the whole file */
len = 0; /* initial value */
for (i = 0; !feof(ifP); ++i) {
size_t bytesRead;
REALLOCARRAY(input, (i+1) * size);
if (input == NULL)
pm_error("Cannot allocate memory");
bytesRead = fread(input + i * size, 1, size, ifP);
len += bytesRead;
}
/* filter out raster data */
height = 0; /* initial value */
width = 0; /* initial value */
pos = 0; /* initial value */
opos = 0; /* initial value */
while (pos < len) {
/* only ESC sequences are regarded */
if (input[pos] == '\x1b' && input[pos+1] == '.') {
unsigned int const k =
input[pos+5] * ((input[pos+7] * 256 + input[pos+6] + 7) / 8);
unsigned int const margin = 256;
if(input[pos+5] == 0)
pm_error("Abnormal height value in escape sequence");
height += input[pos+5];
if(width == 0) /* initialize */
width = input[pos+7] * 256 + input[pos+6];
else if(width != input[pos+7] * 256 + input[pos+6])
pm_error("Abnormal width value in escape sequence");
REALLOCARRAY(output, opos + k + margin);
if (output == NULL)
pm_error("Cannot allocate memory");
switch (input[pos+2]) {
case 0:
/* copy the data block */
memcpy(output + opos, input + pos + 8, k);
pos += k + 8;
opos += k;
break;
case 1: {
/* inflate the data block */
unsigned int l;
l = dec_epson_rle(k,input+pos+8,output+opos);
pos += l + 8;
opos += k;
}
break;
default:
pm_error("unknown compression mode");
break;
}
}
else
++pos; /* skip bytes outside the ESCX sequence */
}
pbm_writepbminit(stdout, width, height, 0);
fwrite(output, opos, 1, stdout);
free(input); free(output);
fclose(stdout); fclose(ifP);
return 0;
}
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