1 /* 2 * ReplayGainAnalysis - analyzes input samples and give the recommended dB change 3 * Copyright (C) 2001 David Robinson and Glen Sawyer 4 * 5 * This library is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU Lesser General Public 7 * License as published by the Free Software Foundation; either 8 * version 2.1 of the License, or (at your option) any later version. 9 * 10 * This library is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * Lesser General Public License for more details. 14 * 15 * You should have received a copy of the GNU Lesser General Public 16 * License along with this library; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 18 * 19 * concept and filter values by David Robinson (David@Robinson.org) 20 * -- blame him if you think the idea is flawed 21 * coding by Glen Sawyer (glensawyer@hotmail.com) 442 N 700 E, Provo, UT 84606 USA 22 * -- blame him if you think this runs too slowly, or the coding is otherwise flawed 23 * minor cosmetic tweaks to integrate with FLAC by Josh Coalson 24 * 25 * For an explanation of the concepts and the basic algorithms involved, go to: 26 * http://www.replaygain.org/ 27 */ 28 29 #ifndef GAIN_ANALYSIS_H 30 #define GAIN_ANALYSIS_H 31 32 #include <stddef.h> 33 34 #define GAIN_NOT_ENOUGH_SAMPLES -24601 35 #define GAIN_ANALYSIS_ERROR 0 36 #define GAIN_ANALYSIS_OK 1 37 38 #define INIT_GAIN_ANALYSIS_ERROR 0 39 #define INIT_GAIN_ANALYSIS_OK 1 40 41 #ifdef __cplusplus 42 extern "C" { 43 #endif 44 45 typedef float flac_float_t; /* Type used for filtering */ 46 47 extern flac_float_t ReplayGainReferenceLoudness; /* in dB SPL, currently == 89.0 */ 48 49 int InitGainAnalysis ( long samplefreq ); 50 int ValidGainFrequency ( long samplefreq ); 51 int AnalyzeSamples ( const flac_float_t* left_samples, const flac_float_t* right_samples, size_t num_samples, int num_channels ); 52 flac_float_t GetTitleGain ( void ); 53 flac_float_t GetAlbumGain ( void ); 54 55 #ifdef __cplusplus 56 } 57 #endif 58 59 #endif /* GAIN_ANALYSIS_H */ 60