FFmpeg/libavcodec/sbr.h
Lynne 0b67c83b2e
aacdec_usac, aacsbr: implement SBR support for USAC
Currently, no eSBR features are supported.
Thankfully, no encoders exist for it yet.
2024-06-23 09:10:15 +02:00

227 lines
7.8 KiB
C

/*
* 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 "libavutil/mem_internal.h"
#include "libavutil/tx.h"
#include "aacps.h"
#include "sbrdsp.h"
/**
* 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[9];
AAC_SIGNE bs_num_noise;
uint8_t bs_df_env[9];
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[9][48];
///Envelope scalefactors
uint8_t env_facs_q[9][48];
AAC_FLOAT env_facs[9][48];
///Noise scalefactors
uint8_t noise_facs_q[3][5];
AAC_FLOAT noise_facs[3][5];
///Envelope time borders
uint8_t t_env[9];
///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;
//inter_tes (USAC)
uint8_t temp_shape[6];
uint8_t temp_shape_mode[6];
/** @} */
} SBRData;
typedef struct SpectralBandReplication SpectralBandReplication;
/**
* aacsbr functions pointers
*/
typedef struct AACSBRContext {
int (*sbr_lf_gen)(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 ready_for_dequant;
int id_aac;
int usac;
int inter_tes; // USAC-only
int reset;
SpectrumParameters spectrum_params;
int bs_amp_res_header;
int bs_sbr_preprocessing; // USAC-only
/**
* @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[8][48];
///Dequantized noise scalefactors, remapped
AAC_FLOAT q_mapped[8][48];
///Sinusoidal presence, remapped
uint8_t s_mapped[8][48];
///Estimated envelope
AAC_FLOAT e_curr[8][48];
///Amplitude adjusted noise scalefactors
AAC_FLOAT q_m[8][48];
///Sinusoidal levels
AAC_FLOAT s_m[8][48];
AAC_FLOAT gain[8][48];
DECLARE_ALIGNED(32, INTFLOAT, qmf_filter_scratch)[5][64];
AVTXContext *mdct_ana;
av_tx_fn mdct_ana_fn;
AVTXContext *mdct;
av_tx_fn mdct_fn;
SBRDSPContext dsp;
AACSBRContext c;
};
#endif /* AVCODEC_SBR_H */