rl.h (3904B)
1 /* 2 * Copyright (c) 2000-2002 Fabrice Bellard 3 * Copyright (c) 2002-2004 Michael Niedermayer 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22 /** 23 * @file 24 * rl header. 25 */ 26 27 #ifndef AVCODEC_RL_H 28 #define AVCODEC_RL_H 29 30 #include <stdint.h> 31 32 #include "vlc.h" 33 34 /* run length table */ 35 #define MAX_RUN 64 36 #define MAX_LEVEL 64 37 38 /** RLTable. */ 39 typedef struct RLTable { 40 int n; ///< number of entries of table_vlc minus 1 41 int last; ///< number of values for last = 0 42 const uint16_t (*table_vlc)[2]; 43 const int8_t *table_run; 44 const int8_t *table_level; 45 uint8_t *index_run[2]; ///< encoding only 46 int8_t *max_level[2]; ///< encoding & decoding 47 int8_t *max_run[2]; ///< encoding & decoding 48 RL_VLC_ELEM *rl_vlc[32]; ///< decoding only 49 } RLTable; 50 51 /** 52 * Initialize max_level and index_run from table_run and table_level; 53 * this is equivalent to initializing RLTable.max_level[0] and 54 * RLTable.index_run[0] with ff_rl_init(). 55 */ 56 void ff_rl_init_level_run(uint8_t max_level[MAX_LEVEL + 1], 57 uint8_t index_run[MAX_RUN + 1], 58 const uint8_t table_run[/* n */], 59 const uint8_t table_level[/* n*/], int n); 60 61 /** 62 * Initialize index_run, max_level and max_run from n, last, table_vlc, 63 * table_run and table_level. 64 * @param static_store static uint8_t array[2][2*MAX_RUN + MAX_LEVEL + 3] 65 * to hold the level and run tables. 66 * @note This function does not touch rl_vlc at all, hence there is no need 67 * to synchronize calls to ff_rl_init() and ff_rl_init_vlc() using the 68 * same RLTable. 69 */ 70 void ff_rl_init(RLTable *rl, uint8_t static_store[2][2*MAX_RUN + MAX_LEVEL + 3]); 71 72 /** 73 * Initialize rl_vlc from n, last, table_vlc, table_run and table_level. 74 * All rl_vlc pointers to be initialized must already point to a static 75 * buffer of `static_size` RL_VLC_ELEM elements; if a pointer is NULL, 76 * initializing further VLCs stops. 77 * @note This function does not touch what ff_rl_init() initializes at all, 78 * hence there is no need to synchronize calls to ff_rl_init() and 79 * ff_rl_init_vlc() using the same RLTable. 80 */ 81 void ff_rl_init_vlc(RLTable *rl, unsigned static_size); 82 83 #define VLC_INIT_RL(rl, static_size)\ 84 {\ 85 static RL_VLC_ELEM rl_vlc_table[32][static_size];\ 86 \ 87 for (int q = 0; q < 32; q++) \ 88 rl.rl_vlc[q] = rl_vlc_table[q]; \ 89 \ 90 ff_rl_init_vlc(&rl, static_size); \ 91 } 92 93 #define INIT_FIRST_VLC_RL(rl, static_size) \ 94 do { \ 95 static RL_VLC_ELEM rl_vlc_table[static_size]; \ 96 \ 97 rl.rl_vlc[0] = rl_vlc_table; \ 98 ff_rl_init_vlc(&rl, static_size); \ 99 } while (0) 100 101 static inline int get_rl_index(const RLTable *rl, int last, int run, int level) 102 { 103 int index; 104 index = rl->index_run[last][run]; 105 if (index >= rl->n) 106 return rl->n; 107 if (level > rl->max_level[last][run]) 108 return rl->n; 109 return index + level - 1; 110 } 111 112 #endif /* AVCODEC_RL_H */