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 */ 49