FFmpeg4/libavcodec/huffman.h

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2023-07-02 12:20:28 +00:00
/*
* Copyright (C) 2007 Aurelien Jacobs <aurel@gnuage.org>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* huffman tree builder and VLC generator
*/
#ifndef AVCODEC_HUFFMAN_H
#define AVCODEC_HUFFMAN_H
#include "avcodec.h"
#include "vlc.h"
typedef struct Node {
int16_t sym;
int16_t n0;
uint32_t count;
} Node;
#define FF_HUFFMAN_FLAG_HNODE_FIRST 0x01
#define FF_HUFFMAN_FLAG_ZERO_COUNT 0x02
#define FF_HUFFMAN_BITS 10
typedef int (*HuffCmp)(const void *va, const void *vb);
int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes, int nb_bits,
Node *nodes, HuffCmp cmp, int flags);
int ff_huff_gen_len_table(uint8_t *dst, const uint64_t *stats, int n, int skip0);
#endif /* AVCODEC_HUFFMAN_H */