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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "common/scummsys.h"
/* VLC code
*
* Original copyright note: * Intel Indeo 4 (IV41, IV42, etc.) video decoder for ffmpeg
* written, produced, and directed by Alan Smithee
*/
#ifndef IMAGE_CODECS_INDEO_VLC_H
#define IMAGE_CODECS_INDEO_VLC_H
#include "image/codecs/indeo/get_bits.h"
namespace Image {
namespace Indeo {
#define VLC_TYPE int16
enum VLCFlag {
INIT_VLC_LE = 2,
INIT_VLC_USE_NEW_STATIC = 4
};
struct VLCcode {
uint8 bits;
uint16 symbol;
/**
* codeword, with the first bit-to-be-read in the msb
* (even if intended for a little-endian bitstream reader)
*/
uint32 code;
};
struct VLC {
private:
static int compareVlcSpec(const void *a, const void *b);
/**
* Gets a value of a given size from a table
* @param table Table to get data from
* @param idx Index of value to retrieve
* @param wrap Size of elements with alignment
* @param size Size of elements
*/
static uint getData(const void *table, uint idx, uint wrap, uint size);
public:
int _bits;
VLC_TYPE (*_table)[2]; ///< code, bits
int _tableSize, _tableAllocated;
VLC();
/* Build VLC decoding tables suitable for use with get_vlc().
'nbBits' sets the decoding table size (2^nbBits) entries. The
bigger it is, the faster is the decoding. But it should not be too
big to save memory and L1 cache. '9' is a good compromise.
'nbCodes' : number of vlcs codes
'bits' : table which gives the size (in bits) of each vlc code.
'codes' : table which gives the bit pattern of of each vlc code.
'symbols' : table which gives the values to be returned from get_vlc().
'xxx_wrap' : give the number of bytes between each entry of the
'bits' or 'codes' tables.
'xxx_size' : gives the number of bytes of each entry of the 'bits'
or 'codes' tables.
'wrap' and 'size' make it possible to use any memory configuration and types
(byte/word/long) to store the 'bits', 'codes', and 'symbols' tables.
'useStatic' should be set to 1 for tables, which should be freed
with av_free_static(), 0 if freeVlc() will be used.
*/
int init_vlc(int nbBits, int nbCodes, const void *bits, int bitsWrap,
int bitsSize, const void *codes, int codesWrap, int codesSize,
const void *symbols, int symbolsWrap, int symbolsSize, int flags);
int init_vlc(int nbBits, int nbCodes, const void *bits, int bitsWrap, int bitsSize,
const void *codes, int codesWrap, int codesSize, int flags);
/**
* Free VLC data
*/
void freeVlc();
/**
* Build VLC decoding tables suitable for use with get_vlc().
*
* @param tableNbBits max length of vlc codes to store directly in this table
* (Longer codes are delegated to subtables.)
*
* @param nbCodes number of elements in codes[]
*
* @param codes descriptions of the vlc codes
* These must be ordered such that codes going into the same subtable are contiguous.
* Sorting by VLCcode.code is sufficient, though not necessary.
*/
int buildTable(int tableNbBits, int nbCodes, VLCcode *codes, int flags);
int allocTable(int size, int useStatic);
};
} // End of namespace Indeo
} // End of namespace Image
#endif
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