70 lines
1.8 KiB
C
70 lines
1.8 KiB
C
|
/*
|
||
|
|
* copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
|
||
|
|
*
|
||
|
|
* This file is part of FFmpeg.
|
||
|
|
*
|
||
|
|
* FFmpeg is free software; you can redistribute it and/or
|
||
|
|
* modify it under the terms of the GNU Lesser General Public
|
||
|
|
* License as published by the Free Software Foundation; either
|
||
|
|
* version 2.1 of the License, or (at your option) any later version.
|
||
|
|
*
|
||
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
||
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||
|
|
* Lesser General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU Lesser General Public
|
||
|
|
* License along with FFmpeg; if not, write to the Free Software
|
||
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef AVCODEC_UNARY_H
|
||
|
|
#define AVCODEC_UNARY_H
|
||
|
|
|
||
|
|
#include "get_bits.h"
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Get unary code of limited length
|
||
|
|
* @param gb GetBitContext
|
||
|
|
* @param[in] stop The bitstop value (unary code of 1's or 0's)
|
||
|
|
* @param[in] len Maximum length
|
||
|
|
* @return unary 0 based code index. This is also the length in bits of the
|
||
|
|
* code excluding the stop bit.
|
||
|
|
* (in case len=1)
|
||
|
|
* 1 0
|
||
|
|
* 0 1
|
||
|
|
* (in case len=2)
|
||
|
|
* 1 0
|
||
|
|
* 01 1
|
||
|
|
* 00 2
|
||
|
|
* (in case len=3)
|
||
|
|
* 1 0
|
||
|
|
* 01 1
|
||
|
|
* 001 2
|
||
|
|
* 000 3
|
||
|
|
*/
|
||
|
|
static inline int get_unary(GetBitContext *gb, int stop, int len)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
for(i = 0; i < len && get_bits1(gb) != stop; i++);
|
||
|
|
return i;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Get unary code terminated by a 0 with a maximum length of 33
|
||
|
|
* @param gb GetBitContext
|
||
|
|
* @return Unary length/index
|
||
|
|
*/
|
||
|
|
static inline int get_unary_0_33(GetBitContext *gb)
|
||
|
|
{
|
||
|
|
return get_unary(gb, 0, 33);
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline int get_unary_0_9(GetBitContext *gb)
|
||
|
|
{
|
||
|
|
return get_unary(gb, 0, 9);
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif /* AVCODEC_UNARY_H */
|