text: /*
   * Spectral Band Replication definitions and structures
   * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
   * Copyright (c) 2010      Alex Converse <alex.converse@gmail.com>
   *
   * 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
   * Spectral Band Replication definitions and structures
   * @author Robert Swain ( rob opendot cl )
   */
  
  #ifndef AVCODEC_SBR_H
  #define AVCODEC_SBR_H
  
  #include <stdint.h>
  #include "fft.h"
  #include "aacps.h"
  #include "sbrdsp.h"
  
  typedef struct AACContext AACContext;
  
  /**
   * Spectral Band Replication header - spectrum parameters that invoke a reset if they differ from the previous header.
   */
  typedef struct SpectrumParameters {
      uint8_t bs_start_freq;
      uint8_t bs_stop_freq;
      uint8_t bs_xover_band;
  
      /**
       * @name Variables associated with bs_header_extra_1
       * @{
       */
      uint8_t bs_freq_scale;
      uint8_t bs_alter_scale;
      uint8_t bs_noise_bands;
      /** @} */
  } SpectrumParameters;
  
  #define SBR_SYNTHESIS_BUF_SIZE ((1280-128)*2)
  
  /**
   * Spectral Band Replication per channel data
   */
  typedef struct SBRData {
      /**
       * @name Main bitstream data variables
       * @{
       */
      unsigned           bs_frame_class;
      unsigned           bs_add_harmonic_flag;
      AAC_SIGNE          bs_num_env;
      uint8_t            bs_freq_res[7];
      AAC_SIGNE          bs_num_noise;
      uint8_t            bs_df_env[5];
      uint8_t            bs_df_noise[2];
      uint8_t            bs_invf_mode[2][5];
      uint8_t            bs_add_harmonic[48];
      unsigned           bs_amp_res;
      /** @} */
  
      /**
       * @name State variables
       * @{
       */
      DECLARE_ALIGNED(32, INTFLOAT, synthesis_filterbank_samples)[SBR_SYNTHESIS_BUF_SIZE];
      DECLARE_ALIGNED(32, INTFLOAT, analysis_filterbank_samples) [1312];
      int                synthesis_filterbank_samples_offset;
      ///l_APrev and l_A
      int                e_a[2];
      ///Chirp factors
      INTFLOAT              bw_array[5];
      ///QMF values of the original signal
      INTFLOAT              W[2][32][32][2];
      ///QMF output of the HF adjustor
      int                Ypos;
      DECLARE_ALIGNED(16, INTFLOAT, Y)[2][38][64][2];
      DECLARE_ALIGNED(16, AAC_FLOAT, g_temp)[42][48];
      AAC_FLOAT          q_temp[42][48];
      uint8_t            s_indexmapped[8][48];
      ///Envelope scalefactors
      AAC_FLOAT          env_facs[6][48];
      ///Noise scalefactors
      AAC_FLOAT          noise_facs[3][5];
      ///Envelope time borders
      uint8_t            t_env[8];
      ///Envelope time border of the last envelope of the previous frame
      uint8_t            t_env_num_env_old;
      ///Noise time borders
      uint8_t            t_q[3];
      unsigned           f_indexnoise;
      unsigned           f_indexsine;
      /** @} */
  } SBRData;
  
  typedef struct SpectralBandReplication SpectralBandReplication;
  
  /**
   * aacsbr functions pointers
   */
  typedef struct AACSBRContext {
      int (*sbr_lf_gen)(AACContext *ac, SpectralBandReplication *sbr,
                        INTFLOAT X_low[32][40][2], const INTFLOAT W[2][32][32][2],
                        int buf_idx);
      void (*sbr_hf_assemble)(INTFLOAT Y1[38][64][2],
                              const INTFLOAT X_high[64][40][2],
                              SpectralBandReplication *sbr, SBRData *ch_data,
                              const int e_a[2]);
      int (*sbr_x_gen)(SpectralBandReplication *sbr, INTFLOAT X[2][38][64],
                       const INTFLOAT Y0[38][64][2], const INTFLOAT Y1[38][64][2],
                       const INTFLOAT X_low[32][40][2], int ch);
      void (*sbr_hf_inverse_filter)(SBRDSPContext *dsp,
                                    INTFLOAT (*alpha0)[2], INTFLOAT (*alpha1)[2],
                                    const INTFLOAT X_low[32][40][2], int k0);
  } AACSBRContext;
  
  /**
   * Spectral Band Replication
   */
  struct SpectralBandReplication {
      int                sample_rate;
      int                start;
      int                id_aac;
      int                reset;
      SpectrumParameters spectrum_params;
      int                bs_amp_res_header;
      /**
       * @name Variables associated with bs_header_extra_2
       * @{
       */
      unsigned           bs_limiter_bands;
      unsigned           bs_limiter_gains;
      unsigned           bs_interpol_freq;
      unsigned           bs_smoothing_mode;
      /** @} */
      unsigned           bs_coupling;
      AAC_SIGNE          k[5]; ///< k0, k1, k2
      ///kx', and kx respectively, kx is the first QMF subband where SBR is used.
      ///kx' is its value from the previous frame
      AAC_SIGNE          kx[2];
      ///M' and M respectively, M is the number of QMF subbands that use SBR.
      AAC_SIGNE          m[2];
      unsigned           kx_and_m_pushed;
      ///The number of frequency bands in f_master
      AAC_SIGNE          n_master;
      SBRData            data[2];
      PSContext          ps;
      ///N_Low and N_High respectively, the number of frequency bands for low and high resolution
      AAC_SIGNE          n[2];
      ///Number of noise floor bands
      AAC_SIGNE          n_q;
      ///Number of limiter bands
      AAC_SIGNE          n_lim;
      ///The master QMF frequency grouping
      uint16_t           f_master[49];
      ///Frequency borders for low resolution SBR
      uint16_t           f_tablelow[25];
      ///Frequency borders for high resolution SBR
      uint16_t           f_tablehigh[49];
      ///Frequency borders for noise floors
      uint16_t           f_tablenoise[6];
      ///Frequency borders for the limiter
      uint16_t           f_tablelim[30];
      AAC_SIGNE          num_patches;
      uint8_t            patch_num_subbands[6];
      uint8_t            patch_start_subband[6];
      ///QMF low frequency input to the HF generator
      DECLARE_ALIGNED(16, INTFLOAT, X_low)[32][40][2];
      ///QMF output of the HF generator
      DECLARE_ALIGNED(16, INTFLOAT, X_high)[64][40][2];
      ///QMF values of the reconstructed signal
      DECLARE_ALIGNED(16, INTFLOAT, X)[2][2][38][64];
      ///Zeroth coefficient used to filter the subband signals
      DECLARE_ALIGNED(16, INTFLOAT, alpha0)[64][2];
      ///First coefficient used to filter the subband signals
      DECLARE_ALIGNED(16, INTFLOAT, alpha1)[64][2];
      ///Dequantized envelope scalefactors, remapped
      AAC_FLOAT          e_origmapped[7][48];
      ///Dequantized noise scalefactors, remapped
      AAC_FLOAT          q_mapped[7][48];
      ///Sinusoidal presence, remapped
      uint8_t            s_mapped[7][48];
      ///Estimated envelope
      AAC_FLOAT          e_curr[7][48];
      ///Amplitude adjusted noise scalefactors
      AAC_FLOAT          q_m[7][48];
      ///Sinusoidal levels
      AAC_FLOAT          s_m[7][48];
      AAC_FLOAT          gain[7][48];
      DECLARE_ALIGNED(32, INTFLOAT, qmf_filter_scratch)[5][64];
      FFTContext         mdct_ana;
      FFTContext         mdct;
      SBRDSPContext      dsp;
      AACSBRContext      c;
  };
  
  #endif /* AVCODEC_SBR_H */
  