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  1. /* cairo - a vector graphics library with display and print output
  2.  *
  3.  * Copyright © 2008 Adrian Johnson
  4.  *
  5.  * This library is free software; you can redistribute it and/or
  6.  * modify it either under the terms of the GNU Lesser General Public
  7.  * License version 2.1 as published by the Free Software Foundation
  8.  * (the "LGPL") or, at your option, under the terms of the Mozilla
  9.  * Public License Version 1.1 (the "MPL"). If you do not alter this
  10.  * notice, a recipient may use your version of this file under either
  11.  * the MPL or the LGPL.
  12.  *
  13.  * You should have received a copy of the LGPL along with this library
  14.  * in the file COPYING-LGPL-2.1; if not, write to the Free Software
  15.  * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
  16.  * You should have received a copy of the MPL along with this library
  17.  * in the file COPYING-MPL-1.1
  18.  *
  19.  * The contents of this file are subject to the Mozilla Public License
  20.  * Version 1.1 (the "License"); you may not use this file except in
  21.  * compliance with the License. You may obtain a copy of the License at
  22.  * http://www.mozilla.org/MPL/
  23.  *
  24.  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
  25.  * OF ANY KIND, either express or implied. See the LGPL or the MPL for
  26.  * the specific language governing rights and limitations.
  27.  *
  28.  * The Original Code is the cairo graphics library.
  29.  *
  30.  * The Initial Developer of the Original Code is Adrian Johnson.
  31.  *
  32.  * Contributor(s):
  33.  *      Adrian Johnson <ajohnson@redneon.com>
  34.  */
  35.  
  36. #include "cairoint.h"
  37.  
  38. #include "cairo-error-private.h"
  39. #include "cairo-image-info-private.h"
  40.  
  41. static uint32_t
  42. _get_be32 (const unsigned char *p)
  43. {
  44.     return p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3];
  45. }
  46.  
  47. /* JPEG (image/jpeg)
  48.  *
  49.  * http://www.w3.org/Graphics/JPEG/itu-t81.pdf
  50.  */
  51.  
  52. /* Markers with no parameters. All other markers are followed by a two
  53.  * byte length of the parameters. */
  54. #define TEM       0x01
  55. #define RST_begin 0xd0
  56. #define RST_end   0xd7
  57. #define SOI       0xd8
  58. #define EOI       0xd9
  59.  
  60. /* Start of frame markers. */
  61. #define SOF0  0xc0
  62. #define SOF1  0xc1
  63. #define SOF2  0xc2
  64. #define SOF3  0xc3
  65. #define SOF5  0xc5
  66. #define SOF6  0xc6
  67. #define SOF7  0xc7
  68. #define SOF9  0xc9
  69. #define SOF10 0xca
  70. #define SOF11 0xcb
  71. #define SOF13 0xcd
  72. #define SOF14 0xce
  73. #define SOF15 0xcf
  74.  
  75. static const unsigned char *
  76. _jpeg_skip_segment (const unsigned char *p)
  77. {
  78.     int len;
  79.  
  80.     p++;
  81.     len = (p[0] << 8) | p[1];
  82.  
  83.     return p + len;
  84. }
  85.  
  86. static void
  87. _jpeg_extract_info (cairo_image_info_t *info, const unsigned char *p)
  88. {
  89.     info->width = (p[6] << 8) + p[7];
  90.     info->height = (p[4] << 8) + p[5];
  91.     info->num_components = p[8];
  92.     info->bits_per_component = p[3];
  93. }
  94.  
  95. cairo_int_status_t
  96. _cairo_image_info_get_jpeg_info (cairo_image_info_t     *info,
  97.                                  const unsigned char    *data,
  98.                                  long                    length)
  99. {
  100.     const unsigned char *p = data;
  101.  
  102.     while (p + 1 < data + length) {
  103.         if (*p != 0xff)
  104.             return CAIRO_INT_STATUS_UNSUPPORTED;
  105.         p++;
  106.  
  107.         switch (*p) {
  108.             /* skip fill bytes */
  109.         case 0xff:
  110.             p++;
  111.             break;
  112.  
  113.         case TEM:
  114.         case SOI:
  115.         case EOI:
  116.             p++;
  117.             break;
  118.  
  119.         case SOF0:
  120.         case SOF1:
  121.         case SOF2:
  122.         case SOF3:
  123.         case SOF5:
  124.         case SOF6:
  125.         case SOF7:
  126.         case SOF9:
  127.         case SOF10:
  128.         case SOF11:
  129.         case SOF13:
  130.         case SOF14:
  131.         case SOF15:
  132.             /* Start of frame found. Extract the image parameters. */
  133.             if (p + 8 > data + length)
  134.                 return CAIRO_INT_STATUS_UNSUPPORTED;
  135.  
  136.             _jpeg_extract_info (info, p);
  137.             return CAIRO_STATUS_SUCCESS;
  138.  
  139.         default:
  140.             if (*p >= RST_begin && *p <= RST_end) {
  141.                 p++;
  142.                 break;
  143.             }
  144.  
  145.             if (p + 2 > data + length)
  146.                 return CAIRO_INT_STATUS_UNSUPPORTED;
  147.  
  148.             p = _jpeg_skip_segment (p);
  149.             break;
  150.         }
  151.     }
  152.  
  153.     return CAIRO_STATUS_SUCCESS;
  154. }
  155.  
  156. /* JPEG 2000 (image/jp2)
  157.  *
  158.  * http://www.jpeg.org/public/15444-1annexi.pdf
  159.  */
  160.  
  161. #define JPX_FILETYPE 0x66747970
  162. #define JPX_JP2_HEADER 0x6A703268
  163. #define JPX_IMAGE_HEADER 0x69686472
  164.  
  165. static const unsigned char _jpx_signature[] = {
  166.     0x00, 0x00, 0x00, 0x0c, 0x6a, 0x50, 0x20, 0x20, 0x0d, 0x0a, 0x87, 0x0a
  167. };
  168.  
  169. static const unsigned char *
  170. _jpx_next_box (const unsigned char *p)
  171. {
  172.     return p + _get_be32 (p);
  173. }
  174.  
  175. static const unsigned char *
  176. _jpx_get_box_contents (const unsigned char *p)
  177. {
  178.     return p + 8;
  179. }
  180.  
  181. static cairo_bool_t
  182. _jpx_match_box (const unsigned char *p, const unsigned char *end, uint32_t type)
  183. {
  184.     uint32_t length;
  185.  
  186.     if (p + 8 < end) {
  187.         length = _get_be32 (p);
  188.         if (_get_be32 (p + 4) == type &&  p + length < end)
  189.             return TRUE;
  190.     }
  191.  
  192.     return FALSE;
  193. }
  194.  
  195. static const unsigned char *
  196. _jpx_find_box (const unsigned char *p, const unsigned char *end, uint32_t type)
  197. {
  198.     while (p < end) {
  199.         if (_jpx_match_box (p, end, type))
  200.             return p;
  201.         p = _jpx_next_box (p);
  202.     }
  203.  
  204.     return NULL;
  205. }
  206.  
  207. static void
  208. _jpx_extract_info (const unsigned char *p, cairo_image_info_t *info)
  209. {
  210.     info->height = _get_be32 (p);
  211.     info->width = _get_be32 (p + 4);
  212.     info->num_components = (p[8] << 8) + p[9];
  213.     info->bits_per_component = p[10];
  214. }
  215.  
  216. cairo_int_status_t
  217. _cairo_image_info_get_jpx_info (cairo_image_info_t      *info,
  218.                                 const unsigned char     *data,
  219.                                 unsigned long            length)
  220. {
  221.     const unsigned char *p = data;
  222.     const unsigned char *end = data + length;
  223.  
  224.     /* First 12 bytes must be the JPEG 2000 signature box. */
  225.     if (length < ARRAY_LENGTH(_jpx_signature) ||
  226.         memcmp(p, _jpx_signature, ARRAY_LENGTH(_jpx_signature)) != 0)
  227.         return CAIRO_INT_STATUS_UNSUPPORTED;
  228.  
  229.     p += ARRAY_LENGTH(_jpx_signature);
  230.  
  231.     /* Next box must be a File Type Box */
  232.     if (! _jpx_match_box (p, end, JPX_FILETYPE))
  233.         return CAIRO_INT_STATUS_UNSUPPORTED;
  234.  
  235.     p = _jpx_next_box (p);
  236.  
  237.     /* Locate the JP2 header box. */
  238.     p = _jpx_find_box (p, end, JPX_JP2_HEADER);
  239.     if (!p)
  240.         return CAIRO_INT_STATUS_UNSUPPORTED;
  241.  
  242.     /* Step into the JP2 header box. First box must be the Image
  243.      * Header */
  244.     p = _jpx_get_box_contents (p);
  245.     if (! _jpx_match_box (p, end, JPX_IMAGE_HEADER))
  246.         return CAIRO_INT_STATUS_UNSUPPORTED;
  247.  
  248.     /* Get the image info */
  249.     p = _jpx_get_box_contents (p);
  250.     _jpx_extract_info (p, info);
  251.  
  252.     return CAIRO_STATUS_SUCCESS;
  253. }
  254.  
  255. /* PNG (image/png)
  256.  *
  257.  * http://www.w3.org/TR/2003/REC-PNG-20031110/
  258.  */
  259.  
  260. #define PNG_IHDR 0x49484452
  261.  
  262. static const unsigned char _png_magic[8] = { 137, 80, 78, 71, 13, 10, 26, 10 };
  263.  
  264. cairo_int_status_t
  265. _cairo_image_info_get_png_info (cairo_image_info_t     *info,
  266.                                const unsigned char     *data,
  267.                                unsigned long            length)
  268. {
  269.     const unsigned char *p = data;
  270.     const unsigned char *end = data + length;
  271.  
  272.     if (length < 8 || memcmp (data, _png_magic, 8) != 0)
  273.        return CAIRO_INT_STATUS_UNSUPPORTED;
  274.  
  275.     p += 8;
  276.  
  277.     /* The first chunk must be IDHR. IDHR has 13 bytes of data plus
  278.      * the 12 bytes of overhead for the chunk. */
  279.     if (p + 13 + 12 > end)
  280.        return CAIRO_INT_STATUS_UNSUPPORTED;
  281.  
  282.     p += 4;
  283.     if (_get_be32 (p) != PNG_IHDR)
  284.        return CAIRO_INT_STATUS_UNSUPPORTED;
  285.  
  286.     p += 4;
  287.     info->width = _get_be32 (p);
  288.     p += 4;
  289.     info->height = _get_be32 (p);
  290.  
  291.     return CAIRO_STATUS_SUCCESS;
  292. }
  293.