FFmpeg
atrac.h
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1 /*
2  * common functions for the ATRAC family of decoders
3  *
4  * Copyright (c) 2009-2013 Maxim Poliakovski
5  * Copyright (c) 2009 Benjamin Larsson
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 /**
25  * @file
26  * ATRAC common header
27  */
28 
29 #ifndef AVCODEC_ATRAC_H
30 #define AVCODEC_ATRAC_H
31 
32 /**
33  * Gain control parameters for one subband.
34  */
35 typedef struct AtracGainInfo {
36  int num_points; ///< number of gain control points
37  int lev_code[7]; ///< level at corresponding control point
38  int loc_code[7]; ///< location of gain control points
40 
41 /**
42  * Gain compensation context structure.
43  */
44 typedef struct AtracGCContext {
45  float gain_tab1[16]; ///< gain compensation level table
46  float gain_tab2[31]; ///< gain compensation interpolation table
47  int id2exp_offset; ///< offset for converting level index into level exponent
48  int loc_scale; ///< scale of location code = 2^loc_scale samples
49  int loc_size; ///< size of location code in samples
51 
52 extern float ff_atrac_sf_table[64];
53 
54 /**
55  * Generate common tables.
56  */
57 void ff_atrac_generate_tables(void);
58 
59 /**
60  * Initialize gain compensation context.
61  *
62  * @param gctx pointer to gain compensation context to initialize
63  * @param id2exp_offset offset for converting level index into level exponent
64  * @param loc_scale location size factor
65  */
66 void ff_atrac_init_gain_compensation(AtracGCContext *gctx, int id2exp_offset,
67  int loc_scale);
68 
69 /**
70  * Apply gain compensation and perform the MDCT overlapping part.
71  *
72  * @param gctx pointer to gain compensation context
73  * @param in input buffer
74  * @param prev previous buffer to perform overlap against
75  * @param gc_now gain control information for current frame
76  * @param gc_next gain control information for next frame
77  * @param num_samples number of samples to process
78  * @param out output data goes here
79  */
80 void ff_atrac_gain_compensation(AtracGCContext *gctx, float *in, float *prev,
81  AtracGainInfo *gc_now, AtracGainInfo *gc_next,
82  int num_samples, float *out);
83 
84 /**
85  * Quadrature mirror synthesis filter.
86  *
87  * @param inlo lower part of spectrum
88  * @param inhi higher part of spectrum
89  * @param nIn size of spectrum buffer
90  * @param pOut out buffer
91  * @param delayBuf delayBuf buffer
92  * @param temp temp buffer
93  */
94 void ff_atrac_iqmf(float *inlo, float *inhi, unsigned int nIn, float *pOut,
95  float *delayBuf, float *temp);
96 
97 #endif /* AVCODEC_ATRAC_H */
out
FILE * out
Definition: movenc.c:54
AtracGCContext::gain_tab2
float gain_tab2[31]
gain compensation interpolation table
Definition: atrac.h:46
ff_atrac_init_gain_compensation
void ff_atrac_init_gain_compensation(AtracGCContext *gctx, int id2exp_offset, int loc_scale)
Initialize gain compensation context.
Definition: atrac.c:69
AtracGainInfo::num_points
int num_points
number of gain control points
Definition: atrac.h:36
AtracGCContext
Gain compensation context structure.
Definition: atrac.h:44
ff_atrac_gain_compensation
void ff_atrac_gain_compensation(AtracGCContext *gctx, float *in, float *prev, AtracGainInfo *gc_now, AtracGainInfo *gc_next, int num_samples, float *out)
Apply gain compensation and perform the MDCT overlapping part.
Definition: atrac.c:87
AtracGainInfo
Gain control parameters for one subband.
Definition: atrac.h:35
AtracGCContext::loc_scale
int loc_scale
scale of location code = 2^loc_scale samples
Definition: atrac.h:48
AtracGainInfo::loc_code
int loc_code[7]
location of gain control points
Definition: atrac.h:38
AtracGCContext::loc_size
int loc_size
size of location code in samples
Definition: atrac.h:49
ff_atrac_generate_tables
void ff_atrac_generate_tables(void)
Generate common tables.
Definition: atrac.c:63
AtracGCContext::gain_tab1
float gain_tab1[16]
gain compensation level table
Definition: atrac.h:45
ff_atrac_iqmf
void ff_atrac_iqmf(float *inlo, float *inhi, unsigned int nIn, float *pOut, float *delayBuf, float *temp)
Quadrature mirror synthesis filter.
Definition: atrac.c:130
AtracGCContext::id2exp_offset
int id2exp_offset
offset for converting level index into level exponent
Definition: atrac.h:47
AtracGainInfo::lev_code
int lev_code[7]
level at corresponding control point
Definition: atrac.h:37
temp
else temp
Definition: vf_mcdeint.c:259
ff_atrac_sf_table
float ff_atrac_sf_table[64]
Definition: atrac.c:38