libavcodec/mpeg12.h

   1 /*
   2  * MPEG1/2 common code
   3  * Copyright (c) 2007 Aurelien Jacobs <aurel@gnuage.org>
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef AVCODEC_MPEG12_H
  23 #define AVCODEC_MPEG12_H
  24
  25 #include "mpegvideo.h"
  26
  27 #define DC_VLC_BITS 9
  28 #define TEX_VLC_BITS 9
  29
  30 static VLC dc_lum_vlc;
  31 static VLC dc_chroma_vlc;
  32
  33 extern uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3];
  34
  35 void ff_mpeg12_common_init(MpegEncContext *s);
  36 void ff_mpeg12_init_vlcs(void);
  37
  38 static inline int decode_dc(GetBitContext *gb, int component)
  39 {
  40     int code, diff;
  41
  42     if (component == 0) {
  43         code = get_vlc2(gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
  44     } else {
  45         code = get_vlc2(gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
  46     }
  47     if (code < 0){
  48         av_log(NULL, AV_LOG_ERROR, "invalid dc code at\n");
  49         return 0xffff;
  50     }
  51     if (code == 0) {
  52         diff = 0;
  53     } else {
  54         diff = get_xbits(gb, code);
  55     }
  56     return diff;
  57 }
  58
  59 extern int ff_mpeg1_decode_block_intra(MpegEncContext *s, DCTELEM *block, int n);
  60
  61 #endif /* AVCODEC_MPEG12_H */