85 lines
2.8 KiB
C++
85 lines
2.8 KiB
C++
/***************************************************************************
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copyright : (C) 2002 - 2008 by Scott Wheeler
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email : wheeler@kde.org
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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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#include <iostream>
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#include "id3v2synchdata.h"
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using namespace TagLib;
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using namespace ID3v2;
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TagLib::uint SynchData::toUInt(const ByteVector &data)
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{
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uint sum = 0;
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bool notSynchSafe = false;
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int last = data.size() > 4 ? 3 : data.size() - 1;
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for(int i = 0; i <= last; i++) {
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if(data[i] & 0x80) {
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notSynchSafe = true;
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break;
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}
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sum |= (data[i] & 0x7f) << ((last - i) * 7);
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}
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if(notSynchSafe) {
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// Invalid data; assume this was created by some buggy software that just
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// put normal integers here rather than syncsafe ones, and try it that
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// way.
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if(data.size() >= 4) {
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sum = data.toUInt(0, true);
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}
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else {
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ByteVector tmp(data);
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tmp.resize(4);
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sum = tmp.toUInt(0, true);
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}
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}
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return sum;
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}
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ByteVector SynchData::fromUInt(uint value)
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{
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ByteVector v(4, 0);
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for(int i = 0; i < 4; i++)
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v[i] = uchar(value >> ((3 - i) * 7) & 0x7f);
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return v;
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}
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ByteVector SynchData::decode(const ByteVector &data)
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{
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ByteVector result = data;
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ByteVector pattern(2, char(0));
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pattern[0] = '\xFF';
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pattern[1] = '\x00';
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return result.replace(pattern, '\xFF');
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}
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