1 /* replaygain_synthesis - Routines for applying ReplayGain to a signal
2  * Copyright (C) 2002,2003,2004,2005,2006,2007  Josh Coalson
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with this library; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 
19 #ifndef FLAC__SHARE__REPLAYGAIN_SYNTHESIS_H
20 #define FLAC__SHARE__REPLAYGAIN_SYNTHESIS_H
21 
22 #include <stdlib.h> /* for size_t */
23 #include "FLAC/ordinals.h"
24 
25 #define FLAC_SHARE__MAX_SUPPORTED_CHANNELS 2
26 
27 typedef enum {
28 	NOISE_SHAPING_NONE = 0,
29 	NOISE_SHAPING_LOW = 1,
30 	NOISE_SHAPING_MEDIUM = 2,
31 	NOISE_SHAPING_HIGH = 3
32 } NoiseShaping;
33 
34 typedef struct {
35 	const float*  FilterCoeff;
36 	FLAC__uint64  Mask;
37 	double        Add;
38 	float         Dither;
39 	float         ErrorHistory     [FLAC_SHARE__MAX_SUPPORTED_CHANNELS] [16];  /* 16th order Noise shaping */
40 	float         DitherHistory    [FLAC_SHARE__MAX_SUPPORTED_CHANNELS] [16];
41 	int           LastRandomNumber [FLAC_SHARE__MAX_SUPPORTED_CHANNELS];
42 	unsigned      LastHistoryIndex;
43 	NoiseShaping  ShapingType;
44 } DitherContext;
45 
46 void FLAC__replaygain_synthesis__init_dither_context(DitherContext *dither, int bits, int shapingtype);
47 
48 /* scale = (float) pow(10., (double)replaygain * 0.05); */
49 size_t FLAC__replaygain_synthesis__apply_gain(FLAC__byte *data_out, FLAC__bool little_endian_data_out, FLAC__bool unsigned_data_out, const FLAC__int32 * const input[], unsigned wide_samples, unsigned channels, const unsigned source_bps, const unsigned target_bps, const double scale, const FLAC__bool hard_limit, FLAC__bool do_dithering, DitherContext *dither_context);
50 
51 #endif
52