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