FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
huffman.h
Go to the documentation of this file.
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 "avcodec.h"
30 #include "vlc.h"
31 
32 typedef struct Node {
33  int16_t sym;
34  int16_t n0;
35  uint32_t count;
36 } Node;
37 
38 #define FF_HUFFMAN_FLAG_HNODE_FIRST 0x01
39 #define FF_HUFFMAN_FLAG_ZERO_COUNT 0x02
40 #define FF_HUFFMAN_BITS 10
41 
42 typedef int (*HuffCmp)(const void *va, const void *vb);
43 int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes, int nb_bits,
44  Node *nodes, HuffCmp cmp, int flags);
45 
46 int ff_huff_gen_len_table(uint8_t *dst, const uint64_t *stats, int n, int skip0);
47 
48 #endif /* AVCODEC_HUFFMAN_H */
int ff_huff_gen_len_table(uint8_t *dst, const uint64_t *stats, int n, int skip0)
Definition: huffman.c:58
int ff_huff_build_tree(AVCodecContext *avctx, 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:157
int(* HuffCmp)(const void *va, const void *vb)
Definition: huffman.h:42
Definition: huffman.h:32
uint8_t
Definition: vlc.h:26
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
int n
Definition: avisynth_c.h:547
Libavcodec external API header.
main external API structure.
Definition: avcodec.h:1657
int16_t n0
Definition: huffman.h:34
int16_t sym
Definition: huffman.h:33
static int flags
Definition: cpu.c:47
static void stats(const struct CachedBuf *in, int n_in, unsigned *_max, unsigned *_sum)
uint32_t count
Definition: huffman.h:35