1  /*
 2   * libsmackerdec - Smacker video decoder
 3   * Copyright (C) 2011 Barry Duncan
 4   *
 5   * This library is free software; you can redistribute it and/or
 6   * modify it under the terms of the GNU Lesser General Public
 7   * License as published by the Free Software Foundation; either
 8   * version 2.1 of the License, or (at your option) any later version.
 9   *
10   * This library is distributed in the hope that it will be useful,
11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   * Lesser General Public License for more details.
14   *
15   * You should have received a copy of the GNU Lesser General Public
16   * License along with this library; if not, write to the Free Software
17   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
18   */
19  
20  #include <HuffmanVLC.h>
21  
22  namespace SmackerCommon {
23  
24  uint16_t VLC_GetCodeBits(BitReader &bits, VLCtable &table)
25  {
26  	uint32_t codeBits = 0;
27  
28  	// search each length array
29  	for (uint32_t i = 0; i < table.size(); i++)
30  	{
31  		// get and add a new bit to codeBits
32  		uint32_t theBit = bits.GetBit() << i;
33  		codeBits |= theBit;
34  
35  		// search for a code match
36  		for (uint32_t j = 0; j < table[i].size(); j++)
37  		{
38  			if (codeBits == table[i][j].code)
39  			{
40  				return table[i][j].symbol;
41  			}
42  		}
43  	}
44  
45  	// shouldn't get here..
46  	return 0;
47  }
48  
49  void VLC_InitTable(VLCtable &table, uint32_t maxLength, uint32_t size, int *lengths, uint32_t *bits)
50  {
51  	table.resize(maxLength);
52  
53  	for (uint32_t i = 0; i < size; i++)
54  	{
55  		VLC newCode;
56  		newCode.symbol = i;
57  		newCode.code   = bits[i];
58  
59  		uint32_t codeLength = lengths[i];
60  
61  		if (codeLength)
62  			table[codeLength - 1].push_back(newCode);
63  	}
64  }
65  
66  uint32_t VLC_GetSize(VLCtable &table)
67  {
68  	return table.size();
69  }
70  
71  } // close namespace SmackerCommon