kolibrios/programs/media/ac97snd/trunk/mpg/getbits.h

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/*
getbits
copyright ?-2006 by the mpg123 project - free software under the terms of the LGPL 2.1
see COPYING and AUTHORS files in distribution or http://mpg123.de
initially written by Michael Hipp
*/
#ifndef _MPG123_GETBITS_H_
#define _MPG123_GETBITS_H_
/* that's the same file as getits.c but with defines to
force inlining */
static unsigned long rval;
static unsigned char rval_uc;
#define backbits(nob) ((void)( \
bsi.bitindex -= nob, \
bsi.wordpointer += (bsi.bitindex>>3), \
bsi.bitindex &= 0x7 ))
#define getbitoffset() ((-bsi.bitindex)&0x7)
#define getbyte() (*bsi.wordpointer++)
#define getbits(nob) ( \
rval = bsi.wordpointer[0], rval <<= 8, rval |= bsi.wordpointer[1], \
rval <<= 8, rval |= bsi.wordpointer[2], rval <<= bsi.bitindex, \
rval &= 0xffffff, bsi.bitindex += nob, \
rval >>= (24-nob), bsi.wordpointer += (bsi.bitindex>>3), \
bsi.bitindex &= 7,rval)
#define getbits_fast(nob) ( \
rval = (unsigned char) (bsi.wordpointer[0] << bsi.bitindex), \
rval |= ((unsigned long) bsi.wordpointer[1]<<bsi.bitindex)>>8, \
rval <<= nob, rval >>= 8, \
bsi.bitindex += nob, bsi.wordpointer += (bsi.bitindex>>3), \
bsi.bitindex &= 7, rval )
#define get1bit() ( \
rval_uc = *bsi.wordpointer << bsi.bitindex, bsi.bitindex++, \
bsi.wordpointer += (bsi.bitindex>>3), bsi.bitindex &= 7, rval_uc>>7 )
#endif