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			81 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			81 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /********************************************************************
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|  *                                                                  *
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|  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
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|  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
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|  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
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|  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
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|  *                                                                  *
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|  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
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|  * by the Xiph.Org Foundation http://www.xiph.org/                  *
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|  *                                                                  *
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|  ********************************************************************
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| 
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|  function: PCM data envelope analysis and manipulation
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|  last mod: $Id: envelope.h 16227 2009-07-08 06:58:46Z xiphmont $
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| 
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|  ********************************************************************/
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| 
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| #ifndef _V_ENVELOPE_
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| #define _V_ENVELOPE_
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| 
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| #include "mdct.h"
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| 
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| #define VE_PRE    16
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| #define VE_WIN    4
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| #define VE_POST   2
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| #define VE_AMP    (VE_PRE+VE_POST-1)
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| 
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| #define VE_BANDS  7
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| #define VE_NEARDC 15
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| 
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| #define VE_MINSTRETCH 2   /* a bit less than short block */
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| #define VE_MAXSTRETCH 12  /* one-third full block */
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| 
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| typedef struct {
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|   float ampbuf[VE_AMP];
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|   int   ampptr;
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| 
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|   float nearDC[VE_NEARDC];
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|   float nearDC_acc;
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|   float nearDC_partialacc;
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|   int   nearptr;
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| 
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| } envelope_filter_state;
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| 
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| typedef struct {
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|   int begin;
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|   int end;
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|   float *window;
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|   float total;
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| } envelope_band;
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| 
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| typedef struct {
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|   int ch;
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|   int winlength;
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|   int searchstep;
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|   float minenergy;
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| 
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|   mdct_lookup  mdct;
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|   float       *mdct_win;
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| 
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|   envelope_band          band[VE_BANDS];
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|   envelope_filter_state *filter;
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|   int   stretch;
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| 
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|   int                   *mark;
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| 
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|   long storage;
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|   long current;
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|   long curmark;
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|   long cursor;
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| } envelope_lookup;
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| 
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| extern void _ve_envelope_init(envelope_lookup *e,vorbis_info *vi);
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| extern void _ve_envelope_clear(envelope_lookup *e);
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| extern long _ve_envelope_search(vorbis_dsp_state *v);
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| extern void _ve_envelope_shift(envelope_lookup *e,long shift);
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| extern int  _ve_envelope_mark(vorbis_dsp_state *v);
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| 
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| 
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| #endif
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