| 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 */ |