FFmpeg
huffman.h
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1 /*
2  * Copyright (C) 2007 Aurelien Jacobs <aurel@gnuage.org>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * huffman tree builder and VLC generator
24  */
25 
26 #ifndef AVCODEC_HUFFMAN_H
27 #define AVCODEC_HUFFMAN_H
28 
29 #include <stdint.h>
30 
31 #include "vlc.h"
32 
33 typedef struct Node {
34  int16_t sym;
35  int16_t n0;
36  uint32_t count;
37 } Node;
38 
39 #define FF_HUFFMAN_FLAG_HNODE_FIRST 0x01
40 #define FF_HUFFMAN_FLAG_ZERO_COUNT 0x02
41 #define FF_HUFFMAN_BITS 10
42 
43 typedef int (*HuffCmp)(const void *va, const void *vb);
44 int ff_huff_build_tree(void *logctx, VLC *vlc, int nb_codes, int nb_bits,
45  Node *nodes, HuffCmp cmp, int flags);
46 
47 int ff_huff_gen_len_table(uint8_t *dst, const uint64_t *stats, int n, int skip0);
48 
49 #endif /* AVCODEC_HUFFMAN_H */
Node
Definition: agm.c:915
stats
static void stats(AVPacket *const *in, int n_in, unsigned *_max, unsigned *_sum)
Definition: vp9_superframe_bsf.c:34
ff_huff_gen_len_table
int ff_huff_gen_len_table(uint8_t *dst, const uint64_t *stats, int n, int skip0)
Definition: huffman.c:57
cmp
static av_always_inline int cmp(MpegEncContext *s, const int x, const int y, const int subx, const int suby, const int size, const int h, int ref_index, int src_index, me_cmp_func cmp_func, me_cmp_func chroma_cmp_func, const int flags)
compares a block (either a full macroblock or a partition thereof) against a proposed motion-compensa...
Definition: motion_est.c:260
Node::n0
int16_t n0
Definition: huffman.h:35
HuffCmp
int(* HuffCmp)(const void *va, const void *vb)
Definition: huffman.h:43
VLC
Definition: vlc.h:26
Node::sym
int16_t sym
Definition: huffman.h:34
ff_huff_build_tree
int ff_huff_build_tree(void *logctx, VLC *vlc, int nb_codes, int nb_bits, Node *nodes, HuffCmp cmp, int flags)
nodes size must be 2*nb_codes first nb_codes nodes.count must be set
Definition: huffman.c:156
vlc.h
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
Node::count
uint32_t count
Definition: huffman.h:36
int
int
Definition: ffmpeg_filter.c:156