1 /* 2 MPEG Maaate: An Australian MPEG audio analysis toolkit 3 Copyright (C) 2000 Commonwealth Scientific and Industrial Research Organisation 4 (CSIRO), Australia. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 19 */ 20 21 /* Here are defined useful functions used by modules */ 22 23 24 #ifndef tools_H 25 #define tools_H 26 27 #include "pluginsPlatform.h" 28 29 /*---------------------- useful values -----------------------*/ 30 31 #define RESTORED_SAMPLE_MAX 5.33333333331 32 //maximum value of a restored sample for layer II 33 34 /*************************** other tools *************************/ 35 36 /*-------------------------- search array ------------------------*/ 37 38 CSAPI_PLUGINS 39 int search_array ( double tab[], double what, int lenght); 40 // return the position in tab of the nearer value of what, 41 // supposing that the array is sorted from min to max 42 43 /*************************** window functions ********************************/ 44 45 CSAPI_PLUGINS 46 double square_window ( unsigned int upto, int x); 47 // square window from 0 to "upto" 48 /* 49 1 _____________ 50 | | 51 0 _____________| |________________ 52 0 upto 53 */ 54 55 CSAPI_PLUGINS 56 double hamming_window ( unsigned int upto, int x); 57 // hamming window from 0 to upto 58 // 0.54 * 0.46 * cos (2 * Pi * x / upto) 59 60 CSAPI_PLUGINS 61 double welch_window ( unsigned int upto, int x); 62 // welch window from 0 to upto 63 // 1-((x-0.5 * upto) / (0.5 * upto))^2 64 65 CSAPI_PLUGINS 66 double bartlett_window ( unsigned int upto, int x); 67 // bartlett window from 0 to upto 68 // 1-|((x-0.5 * upto) / (0.5 * upto))| 69 70 #endif 71