blob: 05208bbee69aaafa4d9dadb736dd93f14176b3ce
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 |
39 | } AtracGainInfo; |
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 |
50 | } AtracGCContext; |
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 */ |
98 |