raze-gles/source/libsmackerdec/src/HuffmanVLC.cpp
2019-09-20 00:42:45 +02:00

71 lines
1.8 KiB
C++

/*
* libsmackerdec - Smacker video decoder
* Copyright (C) 2011 Barry Duncan
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <HuffmanVLC.h>
namespace SmackerCommon {
uint16_t VLC_GetCodeBits(BitReader &bits, VLCtable &table)
{
uint32_t codeBits = 0;
// search each length array
for (uint32_t i = 0; i < table.size(); i++)
{
// get and add a new bit to codeBits
uint32_t theBit = bits.GetBit() << i;
codeBits |= theBit;
// search for a code match
for (uint32_t j = 0; j < table[i].size(); j++)
{
if (codeBits == table[i][j].code)
{
return table[i][j].symbol;
}
}
}
// shouldn't get here..
return 0;
}
void VLC_InitTable(VLCtable &table, uint32_t maxLength, uint32_t size, int *lengths, uint32_t *bits)
{
table.resize(maxLength);
for (uint32_t i = 0; i < size; i++)
{
VLC newCode;
newCode.symbol = i;
newCode.code = bits[i];
uint32_t codeLength = lengths[i];
if (codeLength)
table[codeLength - 1].push_back(newCode);
}
}
uint32_t VLC_GetSize(VLCtable &table)
{
return table.size();
}
} // close namespace SmackerCommon