1 /*
2 * Opus decoder/demuxer common functions
3 * Copyright (c) 2012 Andrew D'Addesio
4 * Copyright (c) 2013-2014 Mozilla Corporation
5 * Copyright (c) 2016 Rostislav Pehlivanov <atomnuker@gmail.com>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 #ifndef AVCODEC_OPUS_CELT_H
25 #define AVCODEC_OPUS_CELT_H
26
27 #include <float.h>
28
29 #include "opus.h"
30 #include "opus_pvq.h"
31 #include "opusdsp.h"
32
33 #include "mdct15.h"
34 #include "libavutil/float_dsp.h"
35 #include "libavutil/libm.h"
36
37 #define CELT_VECTORS 11
38 #define CELT_ALLOC_STEPS 6
39 #define CELT_FINE_OFFSET 21
40 #define CELT_MAX_FINE_BITS 8
41 #define CELT_NORM_SCALE 16384
42 #define CELT_QTHETA_OFFSET 4
43 #define CELT_QTHETA_OFFSET_TWOPHASE 16
44 #define CELT_POSTFILTER_MINPERIOD 15
45 #define CELT_ENERGY_SILENCE (-28.0f)
46
47 typedef struct CeltPVQ CeltPVQ;
48
49 enum CeltSpread {
50 CELT_SPREAD_NONE,
51 CELT_SPREAD_LIGHT,
52 CELT_SPREAD_NORMAL,
53 CELT_SPREAD_AGGRESSIVE
54 };
55
56 enum CeltBlockSize {
57 CELT_BLOCK_120,
58 CELT_BLOCK_240,
59 CELT_BLOCK_480,
60 CELT_BLOCK_960,
61
62 CELT_BLOCK_NB
63 };
64
65 typedef struct CeltBlock {
66 float energy[CELT_MAX_BANDS];
67 float lin_energy[CELT_MAX_BANDS];
68 float error_energy[CELT_MAX_BANDS];
69 float prev_energy[2][CELT_MAX_BANDS];
70
71 uint8_t collapse_masks[CELT_MAX_BANDS];
72
73 /* buffer for mdct output + postfilter */
74 DECLARE_ALIGNED(32, float, buf)[2048];
75 DECLARE_ALIGNED(32, float, coeffs)[CELT_MAX_FRAME_SIZE];
76
77 /* Used by the encoder */
78 DECLARE_ALIGNED(32, float, overlap)[FFALIGN(CELT_OVERLAP, 16)];
79 DECLARE_ALIGNED(32, float, samples)[FFALIGN(CELT_MAX_FRAME_SIZE, 16)];
80
81 /* postfilter parameters */
82 int pf_period_new;
83 float pf_gains_new[3];
84 int pf_period;
85 float pf_gains[3];
86 int pf_period_old;
87 float pf_gains_old[3];
88
89 float emph_coeff;
90 } CeltBlock;
91
92 struct CeltFrame {
93 // constant values that do not change during context lifetime
94 AVCodecContext *avctx;
95 MDCT15Context *imdct[4];
96 AVFloatDSPContext *dsp;
97 CeltBlock block[2];
98 CeltPVQ *pvq;
99 OpusDSP opusdsp;
100 int channels;
101 int output_channels;
102 int apply_phase_inv;
103
104 enum CeltBlockSize size;
105 int start_band;
106 int end_band;
107 int coded_bands;
108 int transient;
109 int pfilter;
110 int skip_band_floor;
111 int tf_select;
112 int alloc_trim;
113 int alloc_boost[CELT_MAX_BANDS];
114 int blocks; /* number of iMDCT blocks in the frame, depends on transient */
115 int blocksize; /* size of each block */
116 int silence; /* Frame is filled with silence */
117 int anticollapse_needed; /* Whether to expect an anticollapse bit */
118 int anticollapse; /* Encoded anticollapse bit */
119 int intensity_stereo;
120 int dual_stereo;
121 int flushed;
122 uint32_t seed;
123 enum CeltSpread spread;
124
125 /* Encoder PF coeffs */
126 int pf_octave;
127 int pf_period;
128 int pf_tapset;
129 float pf_gain;
130
131 /* Bit allocation */
132 int framebits;
133 int remaining;
134 int remaining2;
135 int caps [CELT_MAX_BANDS];
136 int fine_bits [CELT_MAX_BANDS];
137 int fine_priority[CELT_MAX_BANDS];
138 int pulses [CELT_MAX_BANDS];
139 int tf_change [CELT_MAX_BANDS];
140 };
141
142 /* LCG for noise generation */
celt_rng(CeltFrame * f)143 static av_always_inline uint32_t celt_rng(CeltFrame *f)
144 {
145 f->seed = 1664525 * f->seed + 1013904223;
146 return f->seed;
147 }
148
celt_renormalize_vector(float * X,int N,float gain)149 static av_always_inline void celt_renormalize_vector(float *X, int N, float gain)
150 {
151 int i;
152 float g = 1e-15f;
153 for (i = 0; i < N; i++)
154 g += X[i] * X[i];
155 g = gain / sqrtf(g);
156
157 for (i = 0; i < N; i++)
158 X[i] *= g;
159 }
160
161 int ff_celt_init(AVCodecContext *avctx, CeltFrame **f, int output_channels,
162 int apply_phase_inv);
163
164 void ff_celt_free(CeltFrame **f);
165
166 void ff_celt_flush(CeltFrame *f);
167
168 int ff_celt_decode_frame(CeltFrame *f, OpusRangeCoder *rc, float **output,
169 int coded_channels, int frame_size, int startband, int endband);
170
171 #endif /* AVCODEC_OPUS_CELT_H */
172