src/cairo-image-info.c - third_party/cairo - Git at Google

 /* -*- 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)
 {
     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_unaligned_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_unaligned_be32 (p);
 	if (get_unaligned_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_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_int_status_t
 _cairo_image_info_get_jpx_info (cairo_image_info_t	*info,
 				const unsigned char	*data,
 				unsigned 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,
                                unsigned 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_unaligned_be32 (p) != PNG_IHDR)
        return CAIRO_INT_STATUS_UNSUPPORTED;

     p += 4;
     info->width = get_unaligned_be32 (p);
     p += 4;
     info->height = get_unaligned_be32 (p);

     return CAIRO_STATUS_SUCCESS;
 }

 static const unsigned char *
 _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 < 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)
 			return p;
 		}
 		p++;
 	    }
 	}
     }

     return NULL;
 }

 static const unsigned char *
 _jbig2_get_next_segment (const unsigned char  *p,
 			 const unsigned char  *end,
 			 int                  *type,
 			 const unsigned char **data,
 			 unsigned long        *data_len)
 {
     unsigned long seg_num;
     cairo_bool_t big_page_size;
     int num_segs;
     int ref_seg_bytes;
     int referred_size;

     if (p + 6 >= end)
 	return NULL;

     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) {
 	num_segs = get_unaligned_be32 (p) & 0x1fffffff;
 	ref_seg_bytes = 4 + ((num_segs + 1)/8);
     } else {
 	ref_seg_bytes = 1;
     }
     p += ref_seg_bytes;

     if (seg_num <= 256)
 	referred_size = 1;
     else if (seg_num <= 65536)
 	referred_size = 2;
     else
 	referred_size = 4;

     p += num_segs * referred_size;
     p += big_page_size ? 4 : 1;
     if (p + 4 >= end)
 	return NULL;

     *data_len = get_unaligned_be32 (p);
     p += 4;
     *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)
 	    return NULL;

 	*data_len = p - *data;
     } else {
 	p += *data_len;
     }

     if (p < end)
 	return p;
     else
 	return NULL;
 }

 static void
 _jbig2_extract_info (cairo_image_info_t *info, const unsigned char *p)
 {
     info->width = get_unaligned_be32 (p);
     info->height = get_unaligned_be32 (p + 4);
     info->num_components = 1;
     info->bits_per_component = 1;
 }

 cairo_int_status_t
 _cairo_image_info_get_jbig2_info (cairo_image_info_t	*info,
 				  const unsigned char	*data,
 				  unsigned long		 length)
 {
     const unsigned char *p = data;
     const unsigned char *end = data + length;
     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);
 	    return CAIRO_STATUS_SUCCESS;
 	}
     }

     return CAIRO_INT_STATUS_UNSUPPORTED;
 }
	/* -- 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)
	{
	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_unaligned_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_unaligned_be32 (p);
	if (get_unaligned_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_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_int_status_t
	_cairo_image_info_get_jpx_info (cairo_image_info_t *info,
	const unsigned char *data,
	unsigned 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,
	unsigned 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_unaligned_be32 (p) != PNG_IHDR)
	return CAIRO_INT_STATUS_UNSUPPORTED;

	p += 4;
	info->width = get_unaligned_be32 (p);
	p += 4;
	info->height = get_unaligned_be32 (p);

	return CAIRO_STATUS_SUCCESS;
	}

	static const unsigned char *
	_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 < 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)
	return p;
	}
	p++;
	}
	}
	}

	return NULL;
	}

	static const unsigned char *
	_jbig2_get_next_segment (const unsigned char *p,
	const unsigned char *end,
	int *type,
	const unsigned char **data,
	unsigned long *data_len)
	{
	unsigned long seg_num;
	cairo_bool_t big_page_size;
	int num_segs;
	int ref_seg_bytes;
	int referred_size;

	if (p + 6 >= end)
	return NULL;

	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) {
	num_segs = get_unaligned_be32 (p) & 0x1fffffff;
	ref_seg_bytes = 4 + ((num_segs + 1)/8);
	} else {
	ref_seg_bytes = 1;
	}
	p += ref_seg_bytes;

	if (seg_num <= 256)
	referred_size = 1;
	else if (seg_num <= 65536)
	referred_size = 2;
	else
	referred_size = 4;

	p += num_segs * referred_size;
	p += big_page_size ? 4 : 1;
	if (p + 4 >= end)
	return NULL;

	*data_len = get_unaligned_be32 (p);
	p += 4;
	*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)
	return NULL;

	data_len = p - data;
	} else {
	p += *data_len;
	}

	if (p < end)
	return p;
	else
	return NULL;
	}

	static void
	_jbig2_extract_info (cairo_image_info_t info, const unsigned char p)
	{
	info->width = get_unaligned_be32 (p);
	info->height = get_unaligned_be32 (p + 4);
	info->num_components = 1;
	info->bits_per_component = 1;
	}

	cairo_int_status_t
	_cairo_image_info_get_jbig2_info (cairo_image_info_t *info,
	const unsigned char *data,
	unsigned long length)
	{
	const unsigned char *p = data;
	const unsigned char *end = data + length;
	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);
	return CAIRO_STATUS_SUCCESS;
	}
	}

	return CAIRO_INT_STATUS_UNSUPPORTED;
	}