envelope.h (2116B)
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 https://xiph.org/ * 10 * * 11 ******************************************************************** 12 13 function: PCM data envelope analysis and manipulation 14 15 ********************************************************************/ 16 17 #ifndef _V_ENVELOPE_ 18 #define _V_ENVELOPE_ 19 20 #include "mdct.h" 21 22 #define VE_PRE 16 23 #define VE_WIN 4 24 #define VE_POST 2 25 #define VE_AMP (VE_PRE+VE_POST-1) 26 27 #define VE_BANDS 7 28 #define VE_NEARDC 15 29 30 #define VE_MINSTRETCH 2 /* a bit less than short block */ 31 #define VE_MAXSTRETCH 12 /* one-third full block */ 32 33 typedef struct { 34 float ampbuf[VE_AMP]; 35 int ampptr; 36 37 float nearDC[VE_NEARDC]; 38 float nearDC_acc; 39 float nearDC_partialacc; 40 int nearptr; 41 42 } envelope_filter_state; 43 44 typedef struct { 45 int begin; 46 int end; 47 float *window; 48 float total; 49 } envelope_band; 50 51 typedef struct { 52 int ch; 53 int winlength; 54 int searchstep; 55 float minenergy; 56 57 mdct_lookup mdct; 58 float *mdct_win; 59 60 envelope_band band[VE_BANDS]; 61 envelope_filter_state *filter; 62 int stretch; 63 64 int *mark; 65 66 long storage; 67 long current; 68 long curmark; 69 long cursor; 70 } envelope_lookup; 71 72 extern void _ve_envelope_init(envelope_lookup *e,vorbis_info *vi); 73 extern void _ve_envelope_clear(envelope_lookup *e); 74 extern long _ve_envelope_search(vorbis_dsp_state *v); 75 extern void _ve_envelope_shift(envelope_lookup *e,long shift); 76 extern int _ve_envelope_mark(vorbis_dsp_state *v); 77 78 79 #endif