402 lines
13 KiB
C
402 lines
13 KiB
C
#pragma warning(disable:4206) // nonstandard extension used : translation unit is empty
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#ifdef COMPILE_ME
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/*____________________________________________________________________________
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FreeAmp - The Free MP3 Player
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MP3 Decoder originally Copyright (C) 1995-1997 Xing Technology
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Corp. http://www.xingtech.com
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Portions Copyright (C) 1998-1999 EMusic.com
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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$Id: cupini.c,v 1.3 1999/10/19 07:13:08 elrod Exp $
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____________________________________________________________________________*/
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/*=========================================================
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initialization for cup.c - include to cup.c
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mpeg audio decoder portable "c"
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mod 8/6/96 add 8 bit output
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mod 5/10/95 add quick (low precision) window
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mod 5/16/95 sb limit for reduced samprate output
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changed from 94% to 100% of Nyquist sb
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mod 11/15/95 for Layer I
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=========================================================*/
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/*-- compiler bug, floating constant overflow w/ansi --*/
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#ifdef _MSC_VER
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#pragma warning(disable:4056)
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#endif
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static const long steps[18] =
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{
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0, 3, 5, 7, 9, 15, 31, 63, 127,
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255, 511, 1023, 2047, 4095, 8191, 16383, 32767, 65535};
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/* ABCD_INDEX = lookqt[mode][sr_index][br_index] */
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/* -1 = invalid */
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static const signed char lookqt[4][3][16] =
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{
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{{1, -1, -1, -1, 2, -1, 2, 0, 0, 0, 1, 1, 1, 1, 1, -1}, /* 44ks stereo */
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{0, -1, -1, -1, 2, -1, 2, 0, 0, 0, 0, 0, 0, 0, 0, -1}, /* 48ks */
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{1, -1, -1, -1, 3, -1, 3, 0, 0, 0, 1, 1, 1, 1, 1, -1}}, /* 32ks */
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{{1, -1, -1, -1, 2, -1, 2, 0, 0, 0, 1, 1, 1, 1, 1, -1}, /* 44ks joint stereo */
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{0, -1, -1, -1, 2, -1, 2, 0, 0, 0, 0, 0, 0, 0, 0, -1}, /* 48ks */
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{1, -1, -1, -1, 3, -1, 3, 0, 0, 0, 1, 1, 1, 1, 1, -1}}, /* 32ks */
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{{1, -1, -1, -1, 2, -1, 2, 0, 0, 0, 1, 1, 1, 1, 1, -1}, /* 44ks dual chan */
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{0, -1, -1, -1, 2, -1, 2, 0, 0, 0, 0, 0, 0, 0, 0, -1}, /* 48ks */
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{1, -1, -1, -1, 3, -1, 3, 0, 0, 0, 1, 1, 1, 1, 1, -1}}, /* 32ks */
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// mono extended beyond legal br index
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// 1,2,2,0,0,0,1,1,1,1,1,1,1,1,1,-1, /* 44ks single chan */
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// 0,2,2,0,0,0,0,0,0,0,0,0,0,0,0,-1, /* 48ks */
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// 1,3,3,0,0,0,1,1,1,1,1,1,1,1,1,-1, /* 32ks */
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// legal mono
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{{1, 2, 2, 0, 0, 0, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1}, /* 44ks single chan */
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{0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, -1, -1, -1, -1, -1}, /* 48ks */
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{1, 3, 3, 0, 0, 0, 1, 1, 1, 1, 1, -1, -1, -1, -1, -1}}, /* 32ks */
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};
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static const long sr_table[8] =
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{22050L, 24000L, 16000L, 1L,
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44100L, 48000L, 32000L, 1L};
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/* bit allocation table look up */
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/* table per mpeg spec tables 3b2a/b/c/d /e is mpeg2 */
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/* look_bat[abcd_index][4][16] */
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static const unsigned char look_bat[5][4][16] =
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{
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/* LOOK_BATA */
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{{0, 1, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17},
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{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17},
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{0, 1, 2, 3, 4, 5, 6, 17, 0, 0, 0, 0, 0, 0, 0, 0},
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{0, 1, 2, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
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/* LOOK_BATB */
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{{0, 1, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17},
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{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17},
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{0, 1, 2, 3, 4, 5, 6, 17, 0, 0, 0, 0, 0, 0, 0, 0},
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{0, 1, 2, 17, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
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/* LOOK_BATC */
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{{0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16},
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{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
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{0, 1, 2, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0},
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{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
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/* LOOK_BATD */
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{{0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16},
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{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
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{0, 1, 2, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0},
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{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
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/* LOOK_BATE */
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{{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15},
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{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
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{0, 1, 2, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 0},
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{0, 1, 2, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
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};
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/* look_nbat[abcd_index]][4] */
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static const unsigned char look_nbat[5][4] =
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{
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{3, 8, 12, 4},
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{3, 8, 12, 7},
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{2, 0, 6, 0},
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{2, 0, 10, 0},
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{4, 0, 7, 19},
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};
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void sbt_mono(float *sample, short *pcm, int n);
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void sbt_dual(float *sample, short *pcm, int n);
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void sbt_dual_mono(float *sample, short *pcm, int n);
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void sbt_dual_left(float *sample, short *pcm, int n);
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void sbt_dual_right(float *sample, short *pcm, int n);
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void sbt16_mono(float *sample, short *pcm, int n);
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void sbt16_dual(float *sample, short *pcm, int n);
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void sbt16_dual_mono(float *sample, short *pcm, int n);
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void sbt16_dual_left(float *sample, short *pcm, int n);
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void sbt16_dual_right(float *sample, short *pcm, int n);
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void sbt8_mono(float *sample, short *pcm, int n);
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void sbt8_dual(float *sample, short *pcm, int n);
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void sbt8_dual_mono(float *sample, short *pcm, int n);
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void sbt8_dual_left(float *sample, short *pcm, int n);
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void sbt8_dual_right(float *sample, short *pcm, int n);
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/*--- 8 bit output ---*/
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void sbtB_mono(float *sample, unsigned char *pcm, int n);
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void sbtB_dual(float *sample, unsigned char *pcm, int n);
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void sbtB_dual_mono(float *sample, unsigned char *pcm, int n);
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void sbtB_dual_left(float *sample, unsigned char *pcm, int n);
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void sbtB_dual_right(float *sample, unsigned char *pcm, int n);
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void sbtB16_mono(float *sample, unsigned char *pcm, int n);
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void sbtB16_dual(float *sample, unsigned char *pcm, int n);
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void sbtB16_dual_mono(float *sample, unsigned char *pcm, int n);
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void sbtB16_dual_left(float *sample, unsigned char *pcm, int n);
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void sbtB16_dual_right(float *sample, unsigned char *pcm, int n);
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void sbtB8_mono(float *sample, unsigned char *pcm, int n);
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void sbtB8_dual(float *sample, unsigned char *pcm, int n);
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void sbtB8_dual_mono(float *sample, unsigned char *pcm, int n);
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void sbtB8_dual_left(float *sample, unsigned char *pcm, int n);
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void sbtB8_dual_right(float *sample, unsigned char *pcm, int n);
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static const SBT_FUNCTION sbt_table[2][3][5] =
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{
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{{sbt_mono, sbt_dual, sbt_dual_mono, sbt_dual_left, sbt_dual_right},
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{sbt16_mono, sbt16_dual, sbt16_dual_mono, sbt16_dual_left, sbt16_dual_right},
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{sbt8_mono, sbt8_dual, sbt8_dual_mono, sbt8_dual_left, sbt8_dual_right}},
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{{(SBT_FUNCTION) sbtB_mono,
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(SBT_FUNCTION) sbtB_dual,
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(SBT_FUNCTION) sbtB_dual_mono,
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(SBT_FUNCTION) sbtB_dual_left,
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(SBT_FUNCTION) sbtB_dual_right},
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{(SBT_FUNCTION) sbtB16_mono,
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(SBT_FUNCTION) sbtB16_dual,
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(SBT_FUNCTION) sbtB16_dual_mono,
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(SBT_FUNCTION) sbtB16_dual_left,
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(SBT_FUNCTION) sbtB16_dual_right},
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{(SBT_FUNCTION) sbtB8_mono,
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(SBT_FUNCTION) sbtB8_dual,
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(SBT_FUNCTION) sbtB8_dual_mono,
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(SBT_FUNCTION) sbtB8_dual_left,
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(SBT_FUNCTION) sbtB8_dual_right}},
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};
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static const int out_chans[5] =
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{1, 2, 1, 1, 1};
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int audio_decode_initL1(MPEG_HEAD * h, int framebytes_arg,
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int reduction_code, int transform_code, int convert_code,
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int freq_limit);
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void sbt_init();
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IN_OUT L1audio_decode(unsigned char *bs, signed short *pcm);
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IN_OUT L2audio_decode(unsigned char *bs, signed short *pcm);
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IN_OUT L3audio_decode(unsigned char *bs, unsigned char *pcm);
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static const AUDIO_DECODE_ROUTINE decode_routine_table[4] =
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{
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L2audio_decode,
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(AUDIO_DECODE_ROUTINE)L3audio_decode,
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L2audio_decode,
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L1audio_decode,};
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/*---------------------------------------------------------*/
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static void table_init()
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{
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int i, j;
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int code;
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static int iOnceOnly=0;
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if (!iOnceOnly++)
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{
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/*-- c_values (dequant) --*/
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for (i = 1; i < 18; i++)
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look_c_value[i] = 2.0F / steps[i];
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/*-- scale factor table, scale by 32768 for 16 pcm output --*/
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for (i = 0; i < 64; i++)
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sf_table[i] = (float) (32768.0 * 2.0 * pow(2.0, -i / 3.0));
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/*-- grouped 3 level lookup table 5 bit token --*/
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for (i = 0; i < 32; i++)
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{
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code = i;
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for (j = 0; j < 3; j++)
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{
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group3_table[i][j] = (char) ((code % 3) - 1);
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code /= 3;
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}
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}
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/*-- grouped 5 level lookup table 7 bit token --*/
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for (i = 0; i < 128; i++)
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{
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code = i;
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for (j = 0; j < 3; j++)
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{
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group5_table[i][j] = (char) ((code % 5) - 2);
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code /= 5;
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}
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}
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/*-- grouped 9 level lookup table 10 bit token --*/
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for (i = 0; i < 1024; i++)
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{
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code = i;
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for (j = 0; j < 3; j++)
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{
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group9_table[i][j] = (short) ((code % 9) - 4);
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code /= 9;
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}
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}
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}
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}
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/*---------------------------------------------------------*/
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int L1audio_decode_init(MPEG_HEAD * h, int framebytes_arg,
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int reduction_code, int transform_code, int convert_code,
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int freq_limit);
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int L3audio_decode_init(MPEG_HEAD * h, int framebytes_arg,
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int reduction_code, int transform_code, int convert_code,
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int freq_limit);
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/*---------------------------------------------------------*/
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/* mpeg_head defined in mhead.h frame bytes is without pad */
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int audio_decode_init(MPEG_HEAD * h, int framebytes_arg,
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int reduction_code, int transform_code, int convert_code,
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int freq_limit)
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{
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int i, j, k;
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static int first_pass = 1;
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int abcd_index;
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long samprate;
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int limit;
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int bit_code;
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if (first_pass)
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{
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table_init();
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first_pass = 0;
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}
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/* select decoder routine Layer I,II,III */
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audio_decode_routine = decode_routine_table[h->option & 3];
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if (h->option == 3) /* layer I */
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return L1audio_decode_init(h, framebytes_arg,
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reduction_code, transform_code, convert_code, freq_limit);
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if (h->option == 1) /* layer III */
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return L3audio_decode_init(h, framebytes_arg,
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reduction_code, transform_code, convert_code, freq_limit);
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transform_code = transform_code; /* not used, asm compatability */
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bit_code = 0;
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if (convert_code & 8)
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bit_code = 1;
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convert_code = convert_code & 3; /* higher bits used by dec8 freq cvt */
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if (reduction_code < 0)
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reduction_code = 0;
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if (reduction_code > 2)
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reduction_code = 2;
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if (freq_limit < 1000)
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freq_limit = 1000;
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pMP3Stream->framebytes = framebytes_arg;
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/* check if code handles */
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if (h->option != 2)
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return 0; /* layer II only */
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if (h->sr_index == 3)
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return 0; /* reserved */
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/* compute abcd index for bit allo table selection */
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if (h->id) /* mpeg 1 */
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abcd_index = lookqt[h->mode][h->sr_index][h->br_index];
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else
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abcd_index = 4; /* mpeg 2 */
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if (abcd_index < 0)
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return 0; // fail invalid Layer II bit rate index
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for (i = 0; i < 4; i++)
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for (j = 0; j < 16; j++)
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pMP3Stream->bat[i][j] = look_bat[abcd_index][i][j];
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for (i = 0; i < 4; i++)
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pMP3Stream->nbat[i] = look_nbat[abcd_index][i];
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pMP3Stream->max_sb = pMP3Stream->nbat[0] + pMP3Stream->nbat[1] + pMP3Stream->nbat[2] + pMP3Stream->nbat[3];
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/*----- compute pMP3Stream->nsb_limit --------*/
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samprate = sr_table[4 * h->id + h->sr_index];
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pMP3Stream->nsb_limit = (freq_limit * 64L + samprate / 2) / samprate;
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/*- caller limit -*/
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/*---- limit = 0.94*(32>>reduction_code); ----*/
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limit = (32 >> reduction_code);
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if (limit > 8)
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limit--;
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if (pMP3Stream->nsb_limit > limit)
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pMP3Stream->nsb_limit = limit;
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if (pMP3Stream->nsb_limit > pMP3Stream->max_sb)
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pMP3Stream->nsb_limit = pMP3Stream->max_sb;
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pMP3Stream->outvalues = 1152 >> reduction_code;
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if (h->mode != 3)
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{ /* adjust for 2 channel modes */
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for (i = 0; i < 4; i++)
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pMP3Stream->nbat[i] *= 2;
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pMP3Stream->max_sb *= 2;
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pMP3Stream->nsb_limit *= 2;
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}
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/* set sbt function */
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k = 1 + convert_code;
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if (h->mode == 3)
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{
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k = 0;
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}
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pMP3Stream->sbt = sbt_table[bit_code][reduction_code][k];
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pMP3Stream->outvalues *= out_chans[k];
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if (bit_code)
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pMP3Stream->outbytes = pMP3Stream->outvalues;
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else
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pMP3Stream->outbytes = sizeof(short) * pMP3Stream->outvalues;
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decinfo.channels = out_chans[k];
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decinfo.outvalues = pMP3Stream->outvalues;
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decinfo.samprate = samprate >> reduction_code;
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if (bit_code)
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decinfo.bits = 8;
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else
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decinfo.bits = sizeof(short) * 8;
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decinfo.framebytes = pMP3Stream->framebytes;
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decinfo.type = 0;
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/* clear sample buffer, unused sub bands must be 0 */
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for (i = 0; i < 2304*2; i++) // the *2 here was inserted by me just in case, since the array is now *2, because of stereo files unpacking at 4608 bytes per frame (which may or may not be relevant, but in any case I don't think we use the L1 versions of MP3 now anyway
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sample[i] = 0.0F;
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/* init sub-band transform */
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sbt_init();
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return 1;
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}
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/*---------------------------------------------------------*/
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void audio_decode_info(DEC_INFO * info)
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{
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*info = decinfo; /* info return, call after init */
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}
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/*---------------------------------------------------------*/
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void decode_table_init()
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{
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/* dummy for asm version compatability */
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}
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/*---------------------------------------------------------*/
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#endif // #ifdef COMPILE_ME
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