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1 /*
2  * Spectral Band Replication definitions and structures
3  * Copyright (c) 2008-2009 Robert Swain ( rob opendot cl )
4  * Copyright (c) 2010      Alex Converse <alex.converse@gmail.com>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * Spectral Band Replication definitions and structures
26  * @author Robert Swain ( rob opendot cl )
27  */
28 
29 #ifndef AVCODEC_SBR_H
30 #define AVCODEC_SBR_H
31 
32 #include <stdint.h>
33 
34 #include "libavutil/mem_internal.h"
35 
36 #include "fft.h"
37 #include "aacps.h"
38 #include "sbrdsp.h"
39 
40 typedef struct AACContext AACContext;
41 
42 /**
43  * Spectral Band Replication header - spectrum parameters that invoke a reset if they differ from the previous header.
44  */
45 typedef struct SpectrumParameters {
46     uint8_t bs_start_freq;
47     uint8_t bs_stop_freq;
48     uint8_t bs_xover_band;
49 
50     /**
51      * @name Variables associated with bs_header_extra_1
52      * @{
53      */
54     uint8_t bs_freq_scale;
55     uint8_t bs_alter_scale;
56     uint8_t bs_noise_bands;
57     /** @} */
58 } SpectrumParameters;
59 
60 #define SBR_SYNTHESIS_BUF_SIZE ((1280-128)*2)
61 
62 /**
63  * Spectral Band Replication per channel data
64  */
65 typedef struct SBRData {
66     /**
67      * @name Main bitstream data variables
68      * @{
69      */
70     unsigned           bs_frame_class;
71     unsigned           bs_add_harmonic_flag;
72     AAC_SIGNE          bs_num_env;
73     uint8_t            bs_freq_res[7];
74     AAC_SIGNE          bs_num_noise;
75     uint8_t            bs_df_env[5];
76     uint8_t            bs_df_noise[2];
77     uint8_t            bs_invf_mode[2][5];
78     uint8_t            bs_add_harmonic[48];
79     unsigned           bs_amp_res;
80     /** @} */
81 
82     /**
83      * @name State variables
84      * @{
85      */
86     DECLARE_ALIGNED(32, INTFLOAT, synthesis_filterbank_samples)[SBR_SYNTHESIS_BUF_SIZE];
87     DECLARE_ALIGNED(32, INTFLOAT, analysis_filterbank_samples) [1312];
88     int                synthesis_filterbank_samples_offset;
89     ///l_APrev and l_A
90     int                e_a[2];
91     ///Chirp factors
92     INTFLOAT              bw_array[5];
93     ///QMF values of the original signal
94     INTFLOAT              W[2][32][32][2];
95     ///QMF output of the HF adjustor
96     int                Ypos;
97     DECLARE_ALIGNED(16, INTFLOAT, Y)[2][38][64][2];
98     DECLARE_ALIGNED(16, AAC_FLOAT, g_temp)[42][48];
99     AAC_FLOAT          q_temp[42][48];
100     uint8_t            s_indexmapped[8][48];
101     ///Envelope scalefactors
102     uint8_t            env_facs_q[6][48];
103     AAC_FLOAT          env_facs[6][48];
104     ///Noise scalefactors
105     uint8_t            noise_facs_q[3][5];
106     AAC_FLOAT          noise_facs[3][5];
107     ///Envelope time borders
108     uint8_t            t_env[8];
109     ///Envelope time border of the last envelope of the previous frame
110     uint8_t            t_env_num_env_old;
111     ///Noise time borders
112     uint8_t            t_q[3];
113     unsigned           f_indexnoise;
114     unsigned           f_indexsine;
115     /** @} */
116 } SBRData;
117 
118 typedef struct SpectralBandReplication SpectralBandReplication;
119 
120 /**
121  * aacsbr functions pointers
122  */
123 typedef struct AACSBRContext {
124     int (*sbr_lf_gen)(AACContext *ac, SpectralBandReplication *sbr,
125                       INTFLOAT X_low[32][40][2], const INTFLOAT W[2][32][32][2],
126                       int buf_idx);
127     void (*sbr_hf_assemble)(INTFLOAT Y1[38][64][2],
128                             const INTFLOAT X_high[64][40][2],
129                             SpectralBandReplication *sbr, SBRData *ch_data,
130                             const int e_a[2]);
131     int (*sbr_x_gen)(SpectralBandReplication *sbr, INTFLOAT X[2][38][64],
132                      const INTFLOAT Y0[38][64][2], const INTFLOAT Y1[38][64][2],
133                      const INTFLOAT X_low[32][40][2], int ch);
134     void (*sbr_hf_inverse_filter)(SBRDSPContext *dsp,
135                                   INTFLOAT (*alpha0)[2], INTFLOAT (*alpha1)[2],
136                                   const INTFLOAT X_low[32][40][2], int k0);
137 } AACSBRContext;
138 
139 /**
140  * Spectral Band Replication
141  */
142 struct SpectralBandReplication {
143     int                sample_rate;
144     int                start;
145     int                ready_for_dequant;
146     int                id_aac;
147     int                reset;
148     SpectrumParameters spectrum_params;
149     int                bs_amp_res_header;
150     /**
151      * @name Variables associated with bs_header_extra_2
152      * @{
153      */
154     unsigned           bs_limiter_bands;
155     unsigned           bs_limiter_gains;
156     unsigned           bs_interpol_freq;
157     unsigned           bs_smoothing_mode;
158     /** @} */
159     unsigned           bs_coupling;
160     AAC_SIGNE          k[5]; ///< k0, k1, k2
161     ///kx', and kx respectively, kx is the first QMF subband where SBR is used.
162     ///kx' is its value from the previous frame
163     AAC_SIGNE          kx[2];
164     ///M' and M respectively, M is the number of QMF subbands that use SBR.
165     AAC_SIGNE          m[2];
166     unsigned           kx_and_m_pushed;
167     ///The number of frequency bands in f_master
168     AAC_SIGNE          n_master;
169     SBRData            data[2];
170     PSContext          ps;
171     ///N_Low and N_High respectively, the number of frequency bands for low and high resolution
172     AAC_SIGNE          n[2];
173     ///Number of noise floor bands
174     AAC_SIGNE          n_q;
175     ///Number of limiter bands
176     AAC_SIGNE          n_lim;
177     ///The master QMF frequency grouping
178     uint16_t           f_master[49];
179     ///Frequency borders for low resolution SBR
180     uint16_t           f_tablelow[25];
181     ///Frequency borders for high resolution SBR
182     uint16_t           f_tablehigh[49];
183     ///Frequency borders for noise floors
184     uint16_t           f_tablenoise[6];
185     ///Frequency borders for the limiter
186     uint16_t           f_tablelim[30];
187     AAC_SIGNE          num_patches;
188     uint8_t            patch_num_subbands[6];
189     uint8_t            patch_start_subband[6];
190     ///QMF low frequency input to the HF generator
191     DECLARE_ALIGNED(16, INTFLOAT, X_low)[32][40][2];
192     ///QMF output of the HF generator
193     DECLARE_ALIGNED(16, INTFLOAT, X_high)[64][40][2];
194     ///QMF values of the reconstructed signal
195     DECLARE_ALIGNED(16, INTFLOAT, X)[2][2][38][64];
196     ///Zeroth coefficient used to filter the subband signals
197     DECLARE_ALIGNED(16, INTFLOAT, alpha0)[64][2];
198     ///First coefficient used to filter the subband signals
199     DECLARE_ALIGNED(16, INTFLOAT, alpha1)[64][2];
200     ///Dequantized envelope scalefactors, remapped
201     AAC_FLOAT          e_origmapped[7][48];
202     ///Dequantized noise scalefactors, remapped
203     AAC_FLOAT          q_mapped[7][48];
204     ///Sinusoidal presence, remapped
205     uint8_t            s_mapped[7][48];
206     ///Estimated envelope
207     AAC_FLOAT          e_curr[7][48];
208     ///Amplitude adjusted noise scalefactors
209     AAC_FLOAT          q_m[7][48];
210     ///Sinusoidal levels
211     AAC_FLOAT          s_m[7][48];
212     AAC_FLOAT          gain[7][48];
213     DECLARE_ALIGNED(32, INTFLOAT, qmf_filter_scratch)[5][64];
214     FFTContext         mdct_ana;
215     FFTContext         mdct;
216     SBRDSPContext      dsp;
217     AACSBRContext      c;
218 };
219 
220 #endif /* AVCODEC_SBR_H */
221