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+/***************************************************************************
+ * __________ __ ___.
+ * 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;
+}