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 81