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   1 /*
   2  * This file is part of FFmpeg.
   3  *
   4  * FFmpeg is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * FFmpeg is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with FFmpeg; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #ifndef AVCODEC_VLC_H
  20 #define AVCODEC_VLC_H
  21
  22 #include <stdint.h>
  23
  24 #define VLC_TYPE int16_t
  25
  26 typedef struct VLC {
  27     int bits;
  28     VLC_TYPE (*table)[2]; ///< code, bits
  29     int table_size, table_allocated;
  30 } VLC;
  31
  32 typedef struct RL_VLC_ELEM {
  33     int16_t level;
  34     int8_t len;
  35     uint8_t run;
  36 } RL_VLC_ELEM;
  37
  38 #define init_vlc(vlc, nb_bits, nb_codes,                \
  39                  bits, bits_wrap, bits_size,            \
  40                  codes, codes_wrap, codes_size,         \
  41                  flags)                                 \
  42     ff_init_vlc_sparse(vlc, nb_bits, nb_codes,          \
  43                        bits, bits_wrap, bits_size,      \
  44                        codes, codes_wrap, codes_size,   \
  45                        NULL, 0, 0, flags)
  46
  47 int ff_init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
  48                        const void *bits, int bits_wrap, int bits_size,
  49                        const void *codes, int codes_wrap, int codes_size,
  50                        const void *symbols, int symbols_wrap, int symbols_size,
  51                        int flags);
  52 void ff_free_vlc(VLC *vlc);
  53
  54 /* If INIT_VLC_INPUT_LE is set, the LSB bit of the codes used to
  55  * initialize the VLC table is the first bit to be read. */
  56 #define INIT_VLC_INPUT_LE       2
  57 /* If set the VLC is intended for a little endian bitstream reader. */
  58 #define INIT_VLC_OUTPUT_LE      8
  59 #define INIT_VLC_LE             (INIT_VLC_INPUT_LE | INIT_VLC_OUTPUT_LE)
  60 #define INIT_VLC_USE_NEW_STATIC 4
  61
  62 #define INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g,      \
  63                                       h, i, j, flags, static_size)         \
  64     do {                                                                   \
  65         static VLC_TYPE table[static_size][2];                             \
  66         (vlc)->table           = table;                                    \
  67         (vlc)->table_allocated = static_size;                              \
  68         ff_init_vlc_sparse(vlc, bits, a, b, c, d, e, f, g, h, i, j,        \
  69                            flags | INIT_VLC_USE_NEW_STATIC);               \
  70     } while (0)
  71
  72 #define INIT_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, h, i, j, static_size) \
  73     INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g,          \
  74                                   h, i, j, 0, static_size)
  75
  76 #define INIT_LE_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, h, i, j, static_size) \
  77     INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g,          \
  78                                   h, i, j, INIT_VLC_LE, static_size)
  79
  80 #define INIT_CUSTOM_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, flags, static_size) \
  81     INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g,          \
  82                                   NULL, 0, 0, flags, static_size)
  83
  84 #define INIT_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size)       \
  85     INIT_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, NULL, 0, 0, static_size)
  86
  87 #define INIT_LE_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size) \
  88     INIT_LE_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, NULL, 0, 0, static_size)
  89
  90 #endif /* AVCODEC_VLC_H */