64 lines
2.6 KiB
C++
64 lines
2.6 KiB
C++
/***************************************************************************
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copyright : (C) 2015 by Tsuda Kageyu
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email : tsuda.kageyu@gmail.com
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***************************************************************************/
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/***************************************************************************
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* This library is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU Lesser General Public License version *
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* 2.1 as published by the Free Software Foundation. *
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* *
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* This library is distributed in the hope that it will be useful, but *
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* WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
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* Lesser General Public License for more details. *
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* *
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* You should have received a copy of the GNU Lesser General Public *
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* License along with this library; if not, write to the Free Software *
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA *
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* 02110-1301 USA *
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* *
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* Alternatively, this file is available under the Mozilla Public *
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* License Version 1.1. You may obtain a copy of the License at *
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* http://www.mozilla.org/MPL/ *
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***************************************************************************/
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#ifndef TAGLIB_MPEGUTILS_H
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#define TAGLIB_MPEGUTILS_H
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// THIS FILE IS NOT A PART OF THE TAGLIB API
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#ifndef DO_NOT_DOCUMENT // tell Doxygen not to document this header
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namespace TagLib
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{
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namespace MPEG
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{
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namespace
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{
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/*!
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* MPEG frames can be recognized by the bit pattern 11111111 111, so the
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* first byte is easy to check for, however checking to see if the second byte
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* starts with \e 111 is a bit more tricky, hence these functions.
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*
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* \note This does not check the length of the vector, since this is an
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* internal utility function.
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*/
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inline bool isFrameSync(const ByteVector &bytes, unsigned int offset = 0)
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{
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// 0xFF in the second byte is possible in theory, but it's very unlikely.
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const unsigned char b1 = bytes[offset + 0];
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const unsigned char b2 = bytes[offset + 1];
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return (b1 == 0xFF && b2 != 0xFF && (b2 & 0xE0) == 0xE0);
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}
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}
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}
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}
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#endif
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#endif
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