| 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 */ |