| 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 "get_bits.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 */ |