/********************************************************************

 *                                                                  *

 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *

 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *

 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *

 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *

 *                                                                  *

 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2009             *

 * by the Xiph.Org Foundation http://www.xiph.org/                  *

 *                                                                  *

 ********************************************************************

 function: PCM data envelope analysis and manipulation

 last mod: $Id: envelope.h 16227 2009-07-08 06:58:46Z xiphmont $

 ********************************************************************/

#ifndef _V_ENVELOPE_

#define _V_ENVELOPE_

#include "mdct.h"

#define VE_PRE    16

#define VE_WIN    4

#define VE_POST   2

#define VE_AMP    (VE_PRE+VE_POST-1)

#define VE_BANDS  7

#define VE_NEARDC 15

#define VE_MINSTRETCH 2   /* a bit less than short block */

#define VE_MAXSTRETCH 12  /* one-third full block */

typedef struct {

  float ampbuf[VE_AMP];

  int   ampptr;

  float nearDC[VE_NEARDC];

  float nearDC_acc;

  float nearDC_partialacc;

  int   nearptr;

} envelope_filter_state;

typedef struct {

  int begin;

  int end;

  float *window;

  float total;

} envelope_band;

typedef struct {

  int ch;

  int winlength;

  int searchstep;

  float minenergy;

  mdct_lookup  mdct;

  float       *mdct_win;

  envelope_band          band[VE_BANDS];

  envelope_filter_state *filter;

  int   stretch;

  int                   *mark;

  long storage;

  long current;

  long curmark;

  long cursor;

} envelope_lookup;

extern void _ve_envelope_init(envelope_lookup *e,vorbis_info *vi);

extern void _ve_envelope_clear(envelope_lookup *e);

extern long _ve_envelope_search(vorbis_dsp_state *v);

extern void _ve_envelope_shift(envelope_lookup *e,long shift);

extern int  _ve_envelope_mark(vorbis_dsp_state *v);

#endif