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/* cairo - a vector graphics library with display and print output
*
* Copyright © 2008 Adrian Johnson
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is Adrian Johnson.
*
* Contributor(s):
* Adrian Johnson <ajohnson@redneon.com>
*/
#include "cairoint.h"
#include "cairo-image-info-private.h"
static uint32_t
_get_be32 (const unsigned char *p)
{
return p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3];
}
/* JPEG (image/jpeg)
*
* http://www.w3.org/Graphics/JPEG/itu-t81.pdf
*/
/* Markers with no parameters. All other markers are followed by a two
* byte length of the parameters. */
#define TEM 0x01
#define RST_begin 0xd0
#define RST_end 0xd7
#define SOI 0xd8
#define EOI 0xd9
/* Start of frame markers. */
#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
static const unsigned char *
_jpeg_skip_segment (const unsigned char *p)
{
int len;
p++;
len = (p[0] << 8) | p[1];
return p + len;
}
static void
_jpeg_extract_info (cairo_image_info_t *info, const unsigned char *p)
{
info->width = (p[6] << 8) + p[7];
info->height = (p[4] << 8) + p[5];
info->num_components = p[8];
info->bits_per_component = p[3];
}
cairo_int_status_t
_cairo_image_info_get_jpeg_info (cairo_image_info_t *info,
const unsigned char *data,
long length)
{
const unsigned char *p = data;
while (p + 1 < data + length) {
if (*p != 0xff)
return CAIRO_INT_STATUS_UNSUPPORTED;
p++;
switch (*p) {
/* skip fill bytes */
case 0xff:
p++;
break;
case TEM:
case SOI:
case EOI:
p++;
break;
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:
/* Start of frame found. Extract the image parameters. */
if (p + 8 > data + length)
return CAIRO_INT_STATUS_UNSUPPORTED;
_jpeg_extract_info (info, p);
return CAIRO_STATUS_SUCCESS;
default:
if (*p >= RST_begin && *p <= RST_end) {
p++;
break;
}
if (p + 2 > data + length)
return CAIRO_INT_STATUS_UNSUPPORTED;
p = _jpeg_skip_segment (p);
break;
}
}
return CAIRO_STATUS_SUCCESS;
}
/* JPEG 2000 (image/jp2)
*
* http://www.jpeg.org/public/15444-1annexi.pdf
*/
#define JPX_FILETYPE 0x66747970
#define JPX_JP2_HEADER 0x6A703268
#define JPX_IMAGE_HEADER 0x69686472
static const unsigned char _jpx_signature[] = {
0x00, 0x00, 0x00, 0x0c, 0x6a, 0x50, 0x20, 0x20, 0x0d, 0x0a, 0x87, 0x0a
};
static const unsigned char *
_jpx_next_box (const unsigned char *p)
{
return p + _get_be32 (p);
}
static const unsigned char *
_jpx_get_box_contents (const unsigned char *p)
{
return p + 8;
}
static cairo_bool_t
_jpx_match_box (const unsigned char *p, const unsigned char *end, uint32_t type)
{
uint32_t length;
if (p + 8 < end) {
length = _get_be32 (p);
if (_get_be32 (p + 4) == type && p + length < end)
return TRUE;
}
return FALSE;
}
static const unsigned char *
_jpx_find_box (const unsigned char *p, const unsigned char *end, uint32_t type)
{
while (p < end) {
if (_jpx_match_box (p, end, type))
return p;
p = _jpx_next_box (p);
}
return NULL;
}
static void
_jpx_extract_info (const unsigned char *p, cairo_image_info_t *info)
{
info->height = _get_be32 (p);
info->width = _get_be32 (p + 4);
info->num_components = (p[8] << 8) + p[9];
info->bits_per_component = p[10];
}
cairo_int_status_t
_cairo_image_info_get_jpx_info (cairo_image_info_t *info,
const unsigned char *data,
long length)
{
const unsigned char *p = data;
const unsigned char *end = data + length;
/* First 12 bytes must be the JPEG 2000 signature box. */
if (length < ARRAY_LENGTH(_jpx_signature) ||
memcmp(p, _jpx_signature, ARRAY_LENGTH(_jpx_signature)) != 0)
return CAIRO_INT_STATUS_UNSUPPORTED;
p += ARRAY_LENGTH(_jpx_signature);
/* Next box must be a File Type Box */
if (! _jpx_match_box (p, end, JPX_FILETYPE))
return CAIRO_INT_STATUS_UNSUPPORTED;
p = _jpx_next_box (p);
/* Locate the JP2 header box. */
p = _jpx_find_box (p, end, JPX_JP2_HEADER);
if (!p)
return CAIRO_INT_STATUS_UNSUPPORTED;
/* Step into the JP2 header box. First box must be the Image
* Header */
p = _jpx_get_box_contents (p);
if (! _jpx_match_box (p, end, JPX_IMAGE_HEADER))
return CAIRO_INT_STATUS_UNSUPPORTED;
/* Get the image info */
p = _jpx_get_box_contents (p);
_jpx_extract_info (p, info);
return CAIRO_STATUS_SUCCESS;
}
/* PNG (image/png)
*
* http://www.w3.org/TR/2003/REC-PNG-20031110/
*/
#define PNG_IHDR 0x49484452
static const unsigned char _png_magic[8] = { 137, 80, 78, 71, 13, 10, 26, 10 };
cairo_int_status_t
_cairo_image_info_get_png_info (cairo_image_info_t *info,
const unsigned char *data,
long length)
{
const unsigned char *p = data;
const unsigned char *end = data + length;
if (length < 8 || memcmp (data, _png_magic, 8) != 0)
return CAIRO_INT_STATUS_UNSUPPORTED;
p += 8;
/* The first chunk must be IDHR. IDHR has 13 bytes of data plus
* the 12 bytes of overhead for the chunk. */
if (p + 13 + 12 > end)
return CAIRO_INT_STATUS_UNSUPPORTED;
p += 4;
if (_get_be32 (p) != PNG_IHDR)
return CAIRO_INT_STATUS_UNSUPPORTED;
p += 4;
info->width = _get_be32 (p);
p += 4;
info->height = _get_be32 (p);
return CAIRO_STATUS_SUCCESS;
}
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