| /* | |
| * common functions for the ATRAC family of decoders | |
| * | |
| * Copyright (c) 2009-2013 Maxim Poliakovski | |
| * Copyright (c) 2009 Benjamin Larsson | |
| * | |
| * This file is part of FFmpeg. | |
| * | |
| * FFmpeg is free software; you can redistribute it and/or | |
| * modify it under the terms of the GNU Lesser General Public | |
| * License as published by the Free Software Foundation; either | |
| * version 2.1 of the License, or (at your option) any later version. | |
| * | |
| * FFmpeg is distributed in the hope that it will be useful, | |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| * Lesser General Public License for more details. | |
| * | |
| * You should have received a copy of the GNU Lesser General Public | |
| * License along with FFmpeg; if not, write to the Free Software | |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| */ | |
| /** | |
| * @file | |
| * ATRAC common header | |
| */ | |
| /** | |
| * Gain control parameters for one subband. | |
| */ | |
| typedef struct AtracGainInfo { | |
| int num_points; ///< number of gain control points | |
| int lev_code[7]; ///< level at corresponding control point | |
| int loc_code[7]; ///< location of gain control points | |
| } AtracGainInfo; | |
| /** | |
| * Gain compensation context structure. | |
| */ | |
| typedef struct AtracGCContext { | |
| float gain_tab1[16]; ///< gain compensation level table | |
| float gain_tab2[31]; ///< gain compensation interpolation table | |
| int id2exp_offset; ///< offset for converting level index into level exponent | |
| int loc_scale; ///< scale of location code = 2^loc_scale samples | |
| int loc_size; ///< size of location code in samples | |
| } AtracGCContext; | |
| extern float ff_atrac_sf_table[64]; | |
| /** | |
| * Generate common tables. | |
| */ | |
| void ff_atrac_generate_tables(void); | |
| /** | |
| * Initialize gain compensation context. | |
| * | |
| * @param gctx pointer to gain compensation context to initialize | |
| * @param id2exp_offset offset for converting level index into level exponent | |
| * @param loc_scale location size factor | |
| */ | |
| void ff_atrac_init_gain_compensation(AtracGCContext *gctx, int id2exp_offset, | |
| int loc_scale); | |
| /** | |
| * Apply gain compensation and perform the MDCT overlapping part. | |
| * | |
| * @param gctx pointer to gain compensation context | |
| * @param in input buffer | |
| * @param prev previous buffer to perform overlap against | |
| * @param gc_now gain control information for current frame | |
| * @param gc_next gain control information for next frame | |
| * @param num_samples number of samples to process | |
| * @param out output data goes here | |
| */ | |
| void ff_atrac_gain_compensation(AtracGCContext *gctx, float *in, float *prev, | |
| AtracGainInfo *gc_now, AtracGainInfo *gc_next, | |
| int num_samples, float *out); | |
| /** | |
| * Quadrature mirror synthesis filter. | |
| * | |
| * @param inlo lower part of spectrum | |
| * @param inhi higher part of spectrum | |
| * @param nIn size of spectrum buffer | |
| * @param pOut out buffer | |
| * @param delayBuf delayBuf buffer | |
| * @param temp temp buffer | |
| */ | |
| void ff_atrac_iqmf(float *inlo, float *inhi, unsigned int nIn, float *pOut, | |
| float *delayBuf, float *temp); | |