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/libavcodec/atrac.h

http://github.com/FFmpeg/FFmpeg
C Header | 97 lines | 24 code | 10 blank | 63 comment | 0 complexity | bd50e59becfd1b4c3d157bfc26b2aafe MD5 | raw file
 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 */
35typedef 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
39} AtracGainInfo;
40
41/**
42 *  Gain compensation context structure.
43 */
44typedef 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
50} AtracGCContext;
51
52extern float ff_atrac_sf_table[64];
53
54/**
55 * Generate common tables.
56 */
57void 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 */
66void 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 */
80void 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 */
94void ff_atrac_iqmf(float *inlo, float *inhi, unsigned int nIn, float *pOut,
95                   float *delayBuf, float *temp);
96
97#endif /* AVCODEC_ATRAC_H */