raze-gles/source/common/thirdparty/gain_analysis.h

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2021-03-13 00:21:38 +00:00
/*
* ReplayGainAnalysis - analyzes input samples and give the recommended dB change
* Copyright (C) 2001-2009 David Robinson and Glen Sawyer
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* concept and filter values by David Robinson (David@Robinson.org)
* -- blame him if you think the idea is flawed
* coding by Glen Sawyer (mp3gain@hotmail.com) 735 W 255 N, Orem, UT 84057-4505 USA
* -- blame him if you think this runs too slowly, or the coding is otherwise flawed
*
* For an explanation of the concepts and the basic algorithms involved, go to:
* http://www.replaygain.org/
*/
#ifndef GAIN_ANALYSIS_H
#define GAIN_ANALYSIS_H
#include <stddef.h>
#include <stdint.h>
#define GAIN_NOT_ENOUGH_SAMPLES (-24601)
#define GAIN_ANALYSIS_ERROR 0
#define GAIN_ANALYSIS_OK 1
#define INIT_GAIN_ANALYSIS_ERROR 0
#define INIT_GAIN_ANALYSIS_OK 1
#define STEPS_per_dB 100. // Table entries per dB
#define MAX_dB 120. // Table entries for 0...MAX_dB (normal max. values are 70...80 dB)
#define MAX_SAMP_FREQ 96000. // maximum allowed sample frequency [Hz]
#define RMS_WINDOW_TIME 0.050 // Time slice size [s]
#define YULE_ORDER 10
#define BUTTER_ORDER 2
#define MAX_ORDER (BUTTER_ORDER > YULE_ORDER ? BUTTER_ORDER : YULE_ORDER)
#define MAX_SAMPLES_PER_WINDOW (size_t) (MAX_SAMP_FREQ * RMS_WINDOW_TIME + 1) // max. Samples per Time slice
typedef float Float_t; // Type used for filtering
struct GainAnalyzer
{
int InitGainAnalysis(int samplefreq);
int AnalyzeSamples(const Float_t *left_samples, const Float_t *right_samples, size_t num_samples, int num_channels);
int ResetSampleFrequency(int samplefreq);
Float_t GetTitleGain(void);
Float_t GetAlbumGain(void);
private:
Float_t linprebuf[MAX_ORDER * 2];
Float_t *linpre; // left input samples, with pre-buffer
Float_t lstepbuf[MAX_SAMPLES_PER_WINDOW + MAX_ORDER];
Float_t *lstep; // left "first step" (i.e. post first filter) samples
Float_t loutbuf[MAX_SAMPLES_PER_WINDOW + MAX_ORDER];
Float_t *lout; // left "out" (i.e. post second filter) samples
Float_t rinprebuf[MAX_ORDER * 2];
Float_t *rinpre; // right input samples ...
Float_t rstepbuf[MAX_SAMPLES_PER_WINDOW + MAX_ORDER];
Float_t *rstep;
Float_t routbuf[MAX_SAMPLES_PER_WINDOW + MAX_ORDER];
Float_t *rout;
long sampleWindow; // number of samples required to reach number of milliseconds required for RMS window
long totsamp;
double lsum;
double rsum;
int freqindex;
unsigned int A[(size_t) (STEPS_per_dB * MAX_dB)];
unsigned int B[(size_t) (STEPS_per_dB * MAX_dB)];
void filterYule(const Float_t* input, Float_t* output, size_t nSamples, const Float_t* kernel);
void filterButter(const Float_t* input, Float_t* output, size_t nSamples, const Float_t* kernel);
Float_t analyzeResult(const unsigned int* Array, size_t len);
};
#endif /* GAIN_ANALYSIS_H */