90 lines
2.3 KiB
C++
90 lines
2.3 KiB
C++
/* ScummVM - Graphic Adventure Engine
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*
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* ScummVM is the legal property of its developers, whose names
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* are too numerous to list here. Please refer to the COPYRIGHT
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* file distributed with this source distribution.
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#ifndef IMAGE_CODECS_INDEO_GET_BITS_H
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#define IMAGE_CODECS_INDEO_GET_BITS_H
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#include "common/bitstream.h"
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namespace Image {
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namespace Indeo {
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/**
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* Intel Indeo Bitstream reader
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*/
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class GetBits : public Common::BitStreamMemory8LSB {
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public:
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/**
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* Constructor
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*/
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GetBits(const byte *dataPtr, uint32 dataSize) : Common::BitStreamMemory8LSB(new Common::BitStreamMemoryStream(dataPtr, dataSize), DisposeAfterUse::YES) {}
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/**
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* The number of bits left
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*/
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int getBitsLeft() const { return size() - pos(); }
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/**
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* Parse a VLC code.
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* @param bits is the number of bits which will be read at once, must be
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* identical to nbBits in init_vlc()
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* @param maxDepth is the number of times bits bits must be read to completely
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* read the longest vlc code
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* = (max_vlc_length + bits - 1) / bits
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*/
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template <int maxDepth, int bits>
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int getVLC2(int16 (*table)[2]) {
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int code;
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int n, nbBits;
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unsigned int index;
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index = peekBits<bits>();
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code = table[index][0];
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n = table[index][1];
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if (maxDepth > 1 && n < 0) {
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skip(bits);
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nbBits = -n;
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index = peekBits(nbBits) + code;
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code = table[index][0];
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n = table[index][1];
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if (maxDepth > 2 && n < 0) {
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skip(nbBits);
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nbBits = -n;
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index = peekBits(nbBits) + code;
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code = table[index][0];
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n = table[index][1];
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}
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}
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skip(n);
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return code;
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}
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};
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} // End of namespace Indeo
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} // End of namespace Image
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#endif
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