rockbox/apps/plugins/imageviewer/png/tinfzlib.c
Marcin Bukat e26d0c62e0 Fix and extend imageviewer png support. FS#11641 by me
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28413 a1c6a512-1295-4272-9138-f99709370657
2010-10-31 12:40:49 +00:00

100 lines
3.1 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Original source:
* Copyright (c) 2003 by Joergen Ibsen / Jibz
*
* Rockbox adaptation:
* Copyright (c) 2010 by Marcin Bukat
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
/*
* tinfzlib - tiny zlib decompressor
*
* Copyright (c) 2003 by Joergen Ibsen / Jibz
* All Rights Reserved
*
* http://www.ibsensoftware.com/
*
* This software is provided 'as-is', without any express
* or implied warranty. In no event will the authors be
* held liable for any damages arising from the use of
* this software.
*
* Permission is granted to anyone to use this software
* for any purpose, including commercial applications,
* and to alter it and redistribute it freely, subject to
* the following restrictions:
*
* 1. The origin of this software must not be
* misrepresented; you must not claim that you
* wrote the original software. If you use this
* software in a product, an acknowledgment in
* the product documentation would be appreciated
* but is not required.
*
* 2. Altered source versions must be plainly marked
* as such, and must not be misrepresented as
* being the original software.
*
* 3. This notice may not be removed or altered from
* any source distribution.
*/
#include "tinf.h"
/* This routine do not check adler32 checksum
* as it is tailored to be used as PNG decompressor
* and PNG has crc32 check of the compressed block
* already
*/
int tinf_zlib_uncompress(void *dest, unsigned int *destLen,
const void *source, unsigned int sourceLen)
{
unsigned char *src = (unsigned char *)source;
unsigned char *dst = (unsigned char *)dest;
int res;
unsigned char cmf, flg;
/* -- get header bytes -- */
cmf = src[0];
flg = src[1];
/* -- check format -- */
/* check checksum */
if (((cmf << 8) + flg) % 31) return TINF_DATA_ERROR;
/* check method is deflate */
if ((cmf & 0x0f) != 8) return TINF_DATA_ERROR;
/* check window size is valid */
if ((cmf >> 4) > 7) return TINF_DATA_ERROR;
/* check there is no preset dictionary */
if (flg & 0x20) return TINF_DATA_ERROR;
/* -- inflate -- */
res = tinf_uncompress(dst, destLen, src + 2, sourceLen - 6);
if (res != TINF_OK) return TINF_DATA_ERROR;
return TINF_OK;
}