libavcodec/huffman.h

   1 /*
   2  * Copyright (C) 2007  Aurelien Jacobs <aurel@gnuage.org>
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav 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  * Libav 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 Libav; 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
  41 typedef int (*HuffCmp)(const void *va, const void *vb);
  42 int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes,
  43                        Node *nodes, HuffCmp cmp, int flags);
  44
  45 void ff_huff_gen_len_table(uint8_t *dst, const uint64_t *stats);
  46
  47 #endif /* AVCODEC_HUFFMAN_H */