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* 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
* 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);
#endif /* AVCODEC_ATRAC_H */