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https://github.com/FFmpeg/FFmpeg.git
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b30851c872
In particular, document that they initialize different parts of an RLTable and therefore need not be synchronized. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
106 lines
3.4 KiB
C
106 lines
3.4 KiB
C
/*
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* Copyright (c) 2000-2002 Fabrice Bellard
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* Copyright (c) 2002-2004 Michael Niedermayer
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* rl header.
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*/
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#ifndef AVCODEC_RL_H
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#define AVCODEC_RL_H
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#include <stdint.h>
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#include "vlc.h"
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/* run length table */
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#define MAX_RUN 64
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#define MAX_LEVEL 64
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/** RLTable. */
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typedef struct RLTable {
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int n; ///< number of entries of table_vlc minus 1
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int last; ///< number of values for last = 0
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const uint16_t (*table_vlc)[2];
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const int8_t *table_run;
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const int8_t *table_level;
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uint8_t *index_run[2]; ///< encoding only
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int8_t *max_level[2]; ///< encoding & decoding
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int8_t *max_run[2]; ///< encoding & decoding
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RL_VLC_ELEM *rl_vlc[32]; ///< decoding only
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} RLTable;
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/**
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* Initialize index_run, max_level and max_run from n, last, table_vlc,
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* table_run and table_level.
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* @param static_store static uint8_t array[2][2*MAX_RUN + MAX_LEVEL + 3]
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* to hold the level and run tables.
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* @note This function does not touch rl_vlc at all, hence there is no need
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* to synchronize calls to ff_rl_init() and ff_rl_init_vlc() using the
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* same RLTable.
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*/
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void ff_rl_init(RLTable *rl, uint8_t static_store[2][2*MAX_RUN + MAX_LEVEL + 3]);
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/**
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* Initialize rl_vlc from n, last, table_vlc, table_run and table_level.
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* All rl_vlc pointers to be initialized must already point to a static
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* buffer of `static_size` RL_VLC_ELEM elements; if a pointer is NULL,
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* initializing further VLCs stops.
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* @note This function does not touch what ff_rl_init() initializes at all,
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* hence there is no need to synchronize calls to ff_rl_init() and
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* ff_rl_init_vlc() using the same RLTable.
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*/
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void ff_rl_init_vlc(RLTable *rl, unsigned static_size);
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#define INIT_VLC_RL(rl, static_size)\
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{\
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int q;\
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static RL_VLC_ELEM rl_vlc_table[32][static_size];\
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\
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if(!rl.rl_vlc[0]){\
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for(q=0; q<32; q++)\
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rl.rl_vlc[q]= rl_vlc_table[q];\
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\
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ff_rl_init_vlc(&rl, static_size);\
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}\
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}
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#define INIT_FIRST_VLC_RL(rl, static_size) \
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do { \
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static RL_VLC_ELEM rl_vlc_table[static_size]; \
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\
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rl.rl_vlc[0] = rl_vlc_table; \
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ff_rl_init_vlc(&rl, static_size); \
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} while (0)
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static inline int get_rl_index(const RLTable *rl, int last, int run, int level)
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{
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int index;
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index = rl->index_run[last][run];
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if (index >= rl->n)
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return rl->n;
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if (level > rl->max_level[last][run])
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return rl->n;
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return index + level - 1;
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}
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#endif /* AVCODEC_RL_H */
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