32a595222d
Made the OpenMPT / legacy OpenMPT and mpg123 libraries pre-built. Changed the OpenMPT and vgmstream plugins to import the libraries as they are now. Made mpg123 embedded and imported by the main binary, since it's now shared by two plugins. Signed-off-by: Christopher Snowhill <kode54@gmail.com>
103 lines
2.8 KiB
C
103 lines
2.8 KiB
C
/*
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getbits
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copyright ?-2009 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.org
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initially written by Michael Hipp
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All code is in the header to suggest/force inlining of these small often-used functions.
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This indeed has some impact on performance.
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*/
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#ifndef _MPG123_GETBITS_H_
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#define _MPG123_GETBITS_H_
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#include "mpg123lib_intern.h"
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#include "debug.h"
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#define backbits(fr,nob) ((void)( \
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fr->bits_avail += nob, \
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fr->bitindex -= nob, \
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fr->wordpointer += (fr->bitindex>>3), \
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fr->bitindex &= 0x7 ))
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#define getbitoffset(fr) ((-fr->bitindex)&0x7)
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/* Precomputing the bytes to be read is error-prone, and some over-read
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is even expected for Huffman. Just play safe and return zeros in case
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of overflow. This assumes you made bitindex zero already! */
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#define getbyte(fr) ( (fr)->bits_avail-=8, (fr)->bits_avail >= 0 \
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? *((fr)->wordpointer++) \
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: 0 )
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static unsigned int getbits(mpg123_handle *fr, int number_of_bits)
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{
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unsigned long rval;
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#ifdef DEBUG_GETBITS
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fprintf(stderr,"g%d",number_of_bits);
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#endif
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fr->bits_avail -= number_of_bits;
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/* Safety catch until we got the nasty code fully figured out. */
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/* No, that catch stays here, even if we think we got it figured out! */
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if(fr->bits_avail < 0)
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{
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if(NOQUIET)
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error2( "Tried to read %i bits with %li available."
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, number_of_bits, fr->bits_avail );
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return 0;
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}
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/* This is actually slow: if(!number_of_bits)
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return 0; */
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#if 0
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check_buffer_range(number_of_bits+fr->bitindex);
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#endif
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{
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rval = fr->wordpointer[0];
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rval <<= 8;
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rval |= fr->wordpointer[1];
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rval <<= 8;
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rval |= fr->wordpointer[2];
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rval <<= fr->bitindex;
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rval &= 0xffffff;
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fr->bitindex += number_of_bits;
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rval >>= (24-number_of_bits);
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fr->wordpointer += (fr->bitindex>>3);
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fr->bitindex &= 7;
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}
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#ifdef DEBUG_GETBITS
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fprintf(stderr,":%lx\n",rval);
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#endif
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return rval;
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}
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#define skipbits(fr, nob) fr->ultmp = ( \
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fr->ultmp = fr->wordpointer[0], fr->ultmp <<= 8, fr->ultmp |= fr->wordpointer[1], \
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fr->ultmp <<= 8, fr->ultmp |= fr->wordpointer[2], fr->ultmp <<= fr->bitindex, \
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fr->ultmp &= 0xffffff, fr->bitindex += nob, fr->bits_avail -= nob, \
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fr->ultmp >>= (24-nob), fr->wordpointer += (fr->bitindex>>3), \
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fr->bitindex &= 7 )
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#define getbits_fast(fr, nob) ( \
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fr->ultmp = (unsigned char) (fr->wordpointer[0] << fr->bitindex), \
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fr->ultmp |= ((unsigned long) fr->wordpointer[1]<<fr->bitindex)>>8, \
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fr->ultmp <<= nob, fr->ultmp >>= 8, \
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fr->bitindex += nob, fr->bits_avail -= nob, \
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fr->wordpointer += (fr->bitindex>>3), \
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fr->bitindex &= 7, fr->ultmp )
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#define get1bit(fr) ( \
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fr->uctmp = *fr->wordpointer << fr->bitindex, \
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++fr->bitindex, --fr->bits_avail, \
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fr->wordpointer += (fr->bitindex>>3), fr->bitindex &= 7, fr->uctmp>>7 )
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#endif
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