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Diffstat (limited to 'image/codecs/indeo/vlc.h')
-rw-r--r-- | image/codecs/indeo/vlc.h | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/image/codecs/indeo/vlc.h b/image/codecs/indeo/vlc.h new file mode 100644 index 0000000000..a6dd692732 --- /dev/null +++ b/image/codecs/indeo/vlc.h @@ -0,0 +1,135 @@ +/* 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 |