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/*
* Copyright (C) 2015-2016 Département de l'Instruction Publique (DIP-SEM)
*
* Copyright (C) 2013 Open Education Foundation
*
* Copyright (C) 2010-2013 Groupement d'Intérêt Public pour
* l'Education Numérique en Afrique (GIP ENA)
*
* This file is part of OpenBoard.
*
* OpenBoard 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, version 3 of the License,
* with a specific linking exception for the OpenSSL project's
* "OpenSSL" library (or with modified versions of it that use the
* same license as the "OpenSSL" library).
*
* OpenBoard is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with OpenBoard. If not, see <http://www.gnu.org/licenses/>.
*/
#include "RunLengthDecode.h"
#include <QtGlobal>
#include "core/memcheck.h"
using namespace merge_lib;
bool RunLengthDecode::encode(std::string & decoded)
{
Q_UNUSED(decoded);
return false;
}
/* The encoded data is a sequence of
runs, where each run consists of a length byte followed by 1 to 128 bytes of data. If
the length byte is in the range 0 to 127, the following length + 1 (1 to 128) bytes
are copied literally during decompression. If length is in the range 129 to 255, the
following single byte is to be copied 257 - length (2 to 128) times during decom-
pression. A length value of 128 denotes EOD. */
// Function performs RunLength Decoder for PDF, very simple
bool RunLengthDecode::decode(std::string & encoded)
{
std::string decoded;
for(unsigned enci = 0;enci < encoded.size();)
{
unsigned char c = encoded[enci++];
if( c == 128 )
{
break; //EOD
}
else if( c < 128 )
{
for(int j = 0; j < (c+1);j++)
{
decoded.append(1,encoded[enci]);
}
enci++;
}
else
{
for(int j = 0; j < (257 - c);j++)
{
decoded.append(1,encoded[enci]);
}
enci++;
}
}
return true;
}
void RunLengthDecode::initialize(Object * objectWithStream)
{
Q_UNUSED(objectWithStream);
};