vlc.h

/* 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */
 
#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;
 
    uint32 code;
};
 
struct VLC {
private:
    static int compareVlcSpec(const void *a, const void *b);
 
    static uint getData(const void *table, uint idx, uint wrap, uint size);
public:
    int _bits;
    VLC_TYPE (*_table)[2];  
    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);
 
    void freeVlc();
 
 
    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