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/* $Header$
This is dvipdfm, a DVI to PDF translator.
Copyright (C) 1998, 1999 by Mark A. Wicks
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
The author may be contacted via the e-mail address
mwicks@kettering.edu
*/
#include <stdio.h>
#include "system.h"
#include "mem.h"
#include "mfileio.h"
#include "numbers.h"
#include "dvi.h"
#include "jpeg.h"
#include "pdfobj.h"
#include "pdfspecial.h"
#define verbose 0
#define SOF0 0xc0
#define SOF1 0xc1
#define SOF2 0xc2
#define SOF3 0xc3
#define SOF5 0xc5
#define SOF6 0xc6
#define SOF7 0xc7
#define SOF9 0xc9
#define SOF10 0xca
#define SOF11 0xcb
#define SOF13 0xcd
#define SOF14 0xce
#define SOF15 0xcf
#define SOI 0xd8
#define EOI 0xd9
#define SOS 0xda
#define COM 0xfe
int check_for_jpeg(FILE *file)
{
rewind (file);
if (get_unsigned_byte (file) != 0xff ||
get_unsigned_byte (file) != SOI)
return 0;
return 1;
}
int jpeg_headers (struct jpeg *jpeg)
{
UNSIGNED_BYTE byte;
UNSIGNED_PAIR length;
int i, done;
done = 0;
while (!done) {
if ((byte = get_unsigned_byte (jpeg -> file)) != 0xff)
return 0;
while ((byte = get_unsigned_byte (jpeg -> file)) == 0xff);
length = get_unsigned_pair (jpeg -> file);
length -= 2;
switch (byte) {
case SOF0:
case SOF1:
case SOF2:
case SOF3:
case SOF5:
case SOF6:
case SOF7:
case SOF9:
case SOF10:
case SOF11:
case SOF13:
case SOF14:
case SOF15:
jpeg -> bits_per_color = get_unsigned_byte (jpeg -> file);
jpeg -> height = get_unsigned_pair (jpeg -> file);
jpeg -> width = get_unsigned_pair (jpeg -> file);
jpeg -> colors = get_unsigned_byte (jpeg -> file);
if (verbose) {
fprintf (stderr, "ht=%d,wd=%d,co=%d,bpc=%d\n",
jpeg->height,jpeg->width,jpeg->colors,jpeg->bits_per_color);
}
done = 1;
return 1;
default:
for (i=0; i<length; i++) {
get_unsigned_byte(jpeg -> file);
}
}
}
return 0; /* Not reached */
}
struct jpeg *jpeg_open (FILE *file)
{
struct jpeg *jpeg;
if (!check_for_jpeg(file)) {
fprintf (stderr, "\nNot a JPEG file\n");
return NULL;
}
jpeg = NEW (1, struct jpeg);
jpeg -> file = file;
if (!jpeg_headers(jpeg)) {
fprintf (stderr, "\nCorrupt JPEG file?\n");
RELEASE (jpeg);
return NULL;
}
return jpeg;
}
void jpeg_close (struct jpeg *jpeg)
{
if (jpeg == NULL) {
fprintf (stderr, "jpeg_closed: passed invalid pointer\n");
}
RELEASE (jpeg);
return;
}
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