Subversion Repositories Kolibri OS

/* 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 

 */

#include "cairoint.h"

#include "cairo-error-private.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,

				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_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;

}