rockbox/tools/ucl/src/getbit.h
Jens Arnold 7c21a96e9a Initial check-in of (stripped-down) UCL data compression library v 1.01
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8087 a1c6a512-1295-4272-9138-f99709370657
2005-11-27 23:41:55 +00:00

64 lines
2.1 KiB
C

/* getbit.h -- bit-buffer access
This file is part of the UCL data compression library.
Copyright (C) 1996-2002 Markus Franz Xaver Johannes Oberhumer
All Rights Reserved.
The UCL library is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
The UCL library 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with the UCL library; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Markus F.X.J. Oberhumer
<markus@oberhumer.com>
http://www.oberhumer.com/opensource/ucl/
*/
/***********************************************************************
//
************************************************************************/
#if 1
#define getbit_8(bb, src, ilen) \
(((bb = bb & 0x7f ? bb*2 : ((unsigned)src[ilen++]*2+1)) >> 8) & 1)
#elif 1
#define getbit_8(bb, src, ilen) \
(bb*=2,bb&0xff ? (bb>>8)&1 : ((bb=src[ilen++]*2+1)>>8)&1)
#else
#define getbit_8(bb, src, ilen) \
(((bb*=2, (bb&0xff ? bb : (bb=src[ilen++]*2+1,bb))) >> 8) & 1)
#endif
#define getbit_le16(bb, src, ilen) \
(bb*=2,bb&0xffff ? (bb>>16)&1 : (ilen+=2,((bb=(src[ilen-2]+src[ilen-1]*256u)*2+1)>>16)&1))
#if 1 && defined(UCL_UNALIGNED_OK_4) && (UCL_BYTE_ORDER == UCL_LITTLE_ENDIAN)
#define getbit_le32(bb, bc, src, ilen) \
(bc > 0 ? ((bb>>--bc)&1) : (bc=31,\
bb=*(const ucl_uint32p)((src)+ilen),ilen+=4,(bb>>31)&1))
#else
#define getbit_le32(bb, bc, src, ilen) \
(bc > 0 ? ((bb>>--bc)&1) : (bc=31,\
bb=src[ilen]+src[ilen+1]*0x100+src[ilen+2]*UCL_UINT32_C(0x10000)+src[ilen+3]*UCL_UINT32_C(0x1000000),\
ilen+=4,(bb>>31)&1))
#endif
/*
vi:ts=4:et
*/