libavcodec/unary.h

   1 /*
   2  * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
   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 #ifndef AVCODEC_UNARY_H
  22 #define AVCODEC_UNARY_H
  23
  24 #include "bitstream.h"
  25
  26 /**
  27  * Get unary code of limited length
  28  * @param bc BitstreamContext
  29  * @param[in] stop The bitstop value (unary code of 1's or 0's)
  30  * @param[in] len Maximum length
  31  * @return Unary length/index
  32  */
  33 static inline int get_unary(BitstreamContext *bc, int stop, int len)
  34 {
  35     int i;
  36
  37     for (i = 0; i < len && bitstream_read_bit(bc) != stop; i++)
  38         ;
  39     return i;
  40 }
  41
  42 /**
  43  * Get unary code terminated by a 0 with a maximum length of 33
  44  * @param bc BitstreamContext
  45  * @return Unary length/index
  46  */
  47 static inline int get_unary_0_33(BitstreamContext *bc)
  48 {
  49     return get_unary(bc, 0, 33);
  50 }
  51
  52 static inline int get_unary_0_9(BitstreamContext *bc)
  53 {
  54     return get_unary(bc, 0, 9);
  55 }
  56
  57 #endif /* AVCODEC_UNARY_H */