Lines
0 %
Functions
Branches
/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
/* 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., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, 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-error-private.h"
#include "cairo-image-info-private.h"
/* 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, const unsigned char *end)
{
int len;
p++;
len = (p[0] << 8) | p[1];
if (len > end - p)
return end;
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,
unsigned long length)
const unsigned char *p = data;
while (p + 1 < data + length) {
if (*p != 0xff)
return CAIRO_INT_STATUS_UNSUPPORTED;
switch (*p) {
/* skip fill bytes */
case 0xff:
break;
case TEM:
case SOI:
case EOI:
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 + 9 > data + length)
_jpeg_extract_info (info, p);
return CAIRO_STATUS_SUCCESS;
default:
if (*p >= RST_begin && *p <= RST_end) {
if (p + 3 > data + length)
p = _jpeg_skip_segment (p, data + length);
/* No start of frame found. */
/* 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
};
/* Returns the length of the box starting at p, or 0 if the box is
* invalid or does not fit in the data. */
static size_t
_jpx_box_length (const unsigned char *p, const unsigned char *end)
uint32_t length;
if (p + 8 > end)
return 0;
length = get_unaligned_be32 (p);
/* A length of 0 means that the box extends to the end of the data. */
if (length == 0)
return end - p;
/* A length of 1 means that a 64-bit length follows the box type.
* Such boxes are not supported, nor are the reserved lengths 2
* to 7. */
if (length < 8 || length > (size_t) (end - p))
return length;
_jpx_next_box (const unsigned char *p, const unsigned char *end)
size_t length = _jpx_box_length (p, end);
return p + length;
_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)
return _jpx_box_length (p, end) != 0 && get_unaligned_be32 (p + 4) == type;
_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, end);
return NULL;
static cairo_int_status_t
_jpx_extract_info (const unsigned char *p, cairo_image_info_t *info, const unsigned char *end)
if (p + 11 >= end) {
info->height = get_unaligned_be32 (p);
info->width = get_unaligned_be32 (p + 4);
info->num_components = (p[8] << 8) + p[9];
info->bits_per_component = p[10];
_cairo_image_info_get_jpx_info (cairo_image_info_t *info,
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)
p += ARRAY_LENGTH(_jpx_signature);
/* Next box must be a File Type Box */
if (! _jpx_match_box (p, end, JPX_FILETYPE))
/* Locate the JP2 header box. */
p = _jpx_find_box (p, end, JPX_JP2_HEADER);
if (!p)
/* 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))
/* Get the image info */
return _jpx_extract_info (p, info, end);
/* 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_image_info_get_png_info (cairo_image_info_t *info,
if (length < 8 || memcmp (data, _png_magic, 8) != 0)
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)
p += 4;
if (get_unaligned_be32 (p) != PNG_IHDR)
info->width = get_unaligned_be32 (p);
_jbig2_find_data_end (const unsigned char *p,
const unsigned char *end,
int type)
unsigned char end_seq[2];
int mmr;
/* Segments of type "Immediate generic region" may have an
* unspecified data length. The JBIG2 specification specifies the
* method to find the end of the data for these segments. */
if (type == 36 || type == 38 || type == 39) {
if (p + 18 < end) {
mmr = p[17] & 0x01;
if (mmr) {
/* MMR encoding ends with 0x00, 0x00 */
end_seq[0] = 0x00;
end_seq[1] = 0x00;
} else {
/* Template encoding ends with 0xff, 0xac */
end_seq[0] = 0xff;
end_seq[1] = 0xac;
p += 18;
while (p + 1 < end) {
if (p[0] == end_seq[0] && p[1] == end_seq[1]) {
/* Skip the 2 terminating bytes and the 4 byte row count that follows. */
p += 6;
if (p < end)
_jbig2_get_next_segment (const unsigned char *p,
int *type,
const unsigned char **data,
unsigned long *data_len)
unsigned long seg_num;
cairo_bool_t big_page_size;
uint32_t num_segs;
size_t ref_seg_bytes;
size_t referred_size;
size_t header_len;
if (p + 6 >= end)
seg_num = get_unaligned_be32 (p);
*type = p[4] & 0x3f;
big_page_size = (p[4] & 0x40) != 0;
p += 5;
num_segs = p[0] >> 5;
if (num_segs == 7) {
if (p + 4 >= end)
num_segs = get_unaligned_be32 (p) & 0x1fffffff;
ref_seg_bytes = 4 + ((num_segs + 1)/8);
ref_seg_bytes = 1;
if (seg_num <= 256)
referred_size = 1;
else if (seg_num <= 65536)
referred_size = 2;
else
referred_size = 4;
/* Skip the referred-to segment count and retention flags, the
* referred-to segment numbers and the page association. num_segs
* is less than 2^29, so header_len is at most 0x84000004 and
* header_len + 4 does not overflow, even with a 32-bit size_t. */
header_len = ref_seg_bytes + num_segs * referred_size +
(big_page_size ? 4 : 1);
if (header_len + 4 >= (size_t) (end - p))
p += header_len;
*data_len = get_unaligned_be32 (p);
*data = p;
if (*data_len == 0xffffffff) {
/* if data length is -1 we have to scan through the data to find the end */
p = _jbig2_find_data_end (*data, end, *type);
if (!p || p >= end)
*data_len = p - *data;
if (*data_len >= (size_t) (end - p))
p += *data_len;
_jbig2_extract_info (cairo_image_info_t *info, const unsigned char *p)
info->height = get_unaligned_be32 (p + 4);
info->num_components = 1;
info->bits_per_component = 1;
_cairo_image_info_get_jbig2_info (cairo_image_info_t *info,
int seg_type;
const unsigned char *seg_data;
unsigned long seg_data_len;
while (p && p < end) {
p = _jbig2_get_next_segment (p, end, &seg_type, &seg_data, &seg_data_len);
if (p && seg_type == 48 && seg_data_len > 8) {
/* page information segment */
_jbig2_extract_info (info, seg_data);