libopenraw
|
00001 /* -*- tab-width:4; c-basic-offset:4 -*- */ 00002 /* 00003 * libopenraw - huffman.cpp 00004 * 00005 * Copyright (C) 2008 Rafael Avila de Espindola. 00006 * 00007 * This library is free software: you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public License 00009 * as published by the Free Software Foundation, either version 3 of 00010 * the License, or (at your option) any later version. 00011 * 00012 * This library is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with this library. If not, see 00019 * <http://www.gnu.org/licenses/>. 00020 */ 00021 00022 #include <string> 00023 #include <iostream> 00024 #include "huffman.h" 00025 00026 namespace OpenRaw { 00027 namespace Internals { 00028 00029 void HuffmanDecoder::printTable_(std::string prefix, unsigned int pos) const 00030 { 00031 const HuffmanNode &cur = m_p[pos]; 00032 if (cur.isLeaf) { 00033 std::cerr << prefix << " " << cur.data << "\n"; 00034 } else { 00035 printTable_(prefix + "0", pos + 1); 00036 printTable_(prefix + "1", cur.data); 00037 } 00038 } 00039 00040 HuffmanDecoder::HuffmanDecoder(const HuffmanNode* const p) : m_p(p) 00041 { 00042 } 00043 00044 void HuffmanDecoder::printTable() const 00045 { 00046 printTable_("", 0); 00047 } 00048 00049 unsigned int HuffmanDecoder::decode(BitIterator& i) 00050 { 00051 int cur = 0; 00052 while (!m_p[cur].isLeaf) { 00053 unsigned int bit = i.get(1); 00054 if (bit) 00055 cur = m_p[cur].data; 00056 else 00057 cur = cur + 1; 00058 } 00059 return m_p[cur].data; 00060 } 00061 00062 } 00063 }