/*

  * 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

  */
 
 #ifndef AVCODEC_ATRAC_H
 #define AVCODEC_ATRAC_H
 

 /**
  *  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 */