release/src/router/libvorbis/lib/envelope.h

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *
   4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
   5  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
   6  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
   7  *                                                                  *
   8  * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *
   9  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  10  *                                                                  *
  11  ********************************************************************
  12
  13  function: PCM data envelope analysis and manipulation
  14  last mod: $Id: envelope.h 16227 2009-07-08 06:58:46Z xiphmont $
  15
  16  ********************************************************************/
  17
  18 #ifndef _V_ENVELOPE_
  19 #define _V_ENVELOPE_
  20
  21 #include "mdct.h"
  22
  23 #define VE_PRE    16
  24 #define VE_WIN    4
  25 #define VE_POST   2
  26 #define VE_AMP    (VE_PRE+VE_POST-1)
  27
  28 #define VE_BANDS  7
  29 #define VE_NEARDC 15
  30
  31 #define VE_MINSTRETCH 2   /* a bit less than short block */
  32 #define VE_MAXSTRETCH 12  /* one-third full block */
  33
  34 typedef struct {
  35   float ampbuf[VE_AMP];
  36   int   ampptr;
  37
  38   float nearDC[VE_NEARDC];
  39   float nearDC_acc;
  40   float nearDC_partialacc;
  41   int   nearptr;
  42
  43 } envelope_filter_state;
  44
  45 typedef struct {
  46   int begin;
  47   int end;
  48   float *window;
  49   float total;
  50 } envelope_band;
  51
  52 typedef struct {
  53   int ch;
  54   int winlength;
  55   int searchstep;
  56   float minenergy;
  57
  58   mdct_lookup  mdct;
  59   float       *mdct_win;
  60
  61   envelope_band          band[VE_BANDS];
  62   envelope_filter_state *filter;
  63   int   stretch;
  64
  65   int                   *mark;
  66
  67   long storage;
  68   long current;
  69   long curmark;
  70   long cursor;
  71 } envelope_lookup;
  72
  73 extern void _ve_envelope_init(envelope_lookup *e,vorbis_info *vi);
  74 extern void _ve_envelope_clear(envelope_lookup *e);
  75 extern long _ve_envelope_search(vorbis_dsp_state *v);
  76 extern void _ve_envelope_shift(envelope_lookup *e,long shift);
  77 extern int  _ve_envelope_mark(vorbis_dsp_state *v);
  78
  79
  80 #endif