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