libavcodec/huffman.h

   1 /**
   2  * @file huffman.h
   3  * huffman tree builder and VLC generator
   4  * Copyright (C) 2007  Aurelien Jacobs <aurel@gnuage.org>
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #ifndef FFMPEG_HUFFMAN_H
  24 #define FFMPEG_HUFFMAN_H
  25
  26 #include "avcodec.h"
  27 #include "bitstream.h"
  28
  29 typedef struct {
  30     int16_t  sym;
  31     int16_t  n0;
  32     uint32_t count;
  33 } Node;
  34
  35 #define FF_HUFFMAN_FLAG_HNODE_FIRST 0x01
  36 #define FF_HUFFMAN_FLAG_ZERO_COUNT  0x02
  37
  38 typedef int (*huff_cmp_t)(const void *va, const void *vb);
  39 int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes,
  40                        Node *nodes, huff_cmp_t cmp, int flags);
  41
  42 #endif /* FFMPEG_HUFFMAN_H */