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* Spectral Band Replication definitions and structures
* Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
* Copyright (c) 2010 Alex Converse <>
* 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
* Spectral Band Replication definitions and structures
* @author Robert Swain ( rob opendot cl )
#include <stdint.h>
#include "fft.h"
#include "aacps.h"
* Spectral Band Replication header - spectrum parameters that invoke a reset if they differ from the previous header.
typedef struct {
uint8_t bs_start_freq;
uint8_t bs_stop_freq;
uint8_t bs_xover_band;
* @defgroup bs_header_extra_1 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 {
* @defgroup aac_bitstream Main bitstream data variables
* @{
unsigned bs_frame_class;
unsigned bs_add_harmonic_flag;
unsigned bs_num_env;
uint8_t bs_freq_res[7];
unsigned 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;
/** @} */
* @defgroup state State variables
* @{
DECLARE_ALIGNED(16, float, synthesis_filterbank_samples)[SBR_SYNTHESIS_BUF_SIZE];
DECLARE_ALIGNED(16, float, analysis_filterbank_samples) [1312];
int synthesis_filterbank_samples_offset;
///l_APrev and l_A
int e_a[2];
///Chirp factors
float bw_array[5];
///QMF values of the original signal
float W[2][32][32][2];
///QMF output of the HF adjustor
float Y[2][38][64][2];
float g_temp[42][48];
float q_temp[42][48];
uint8_t s_indexmapped[8][48];
///Envelope scalefactors
float env_facs[6][48];
///Noise scalefactors
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;
* Spectral Band Replication
typedef struct {
int sample_rate;
int start;
int reset;
SpectrumParameters spectrum_params;
int bs_amp_res_header;
* @defgroup bs_header_extra_2 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;
unsigned 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
unsigned kx[2];
///M' and M respectively, M is the number of QMF subbands that use SBR.
unsigned m[2];
///The number of frequency bands in f_master
unsigned n_master;
SBRData data[2];
PSContext ps;
///N_Low and N_High respectively, the number of frequency bands for low and high resolution
unsigned n[2];
///Number of noise floor bands
unsigned n_q;
///Number of limiter bands
unsigned 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[29];
unsigned num_patches;
uint8_t patch_num_subbands[6];
uint8_t patch_start_subband[6];
///QMF low frequency input to the HF generator
float X_low[32][40][2];
///QMF output of the HF generator
float X_high[64][40][2];
///QMF values of the reconstructed signal
DECLARE_ALIGNED(16, float, X)[2][2][38][64];
///Zeroth coefficient used to filter the subband signals
float alpha0[64][2];
///First coefficient used to filter the subband signals
float alpha1[64][2];
///Dequantized envelope scalefactors, remapped
float e_origmapped[7][48];
///Dequantized noise scalefactors, remapped
float q_mapped[7][48];
///Sinusoidal presence, remapped
uint8_t s_mapped[7][48];
///Estimated envelope
float e_curr[7][48];
///Amplitude adjusted noise scalefactors
float q_m[7][48];
///Sinusoidal levels
float s_m[7][48];
float gain[7][48];
DECLARE_ALIGNED(16, float, qmf_filter_scratch)[5][64];
FFTContext mdct_ana;
FFTContext mdct;
} SpectralBandReplication;
#endif /* AVCODEC_SBR_H */
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