path: root/libavcodec/opus_celt.h (plain)
blob: 23c20891cdf27c7052b310c95c8b8dd6f85bc3eb

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
31	#include "mdct15.h"
32	#include "libavutil/float_dsp.h"
33	#include "libavutil/libm.h"
34
35	#define CELT_VECTORS 11
36	#define CELT_ALLOC_STEPS 6
37	#define CELT_FINE_OFFSET 21
38	#define CELT_MAX_FINE_BITS 8
39	#define CELT_NORM_SCALE 16384
40	#define CELT_QTHETA_OFFSET 4
41	#define CELT_QTHETA_OFFSET_TWOPHASE 16
42	#define CELT_EMPH_COEFF 0.85000610f
43	#define CELT_POSTFILTER_MINPERIOD 15
44	#define CELT_ENERGY_SILENCE (-28.0f)
45
46	enum CeltSpread {
47	CELT_SPREAD_NONE,
48	CELT_SPREAD_LIGHT,
49	CELT_SPREAD_NORMAL,
50	CELT_SPREAD_AGGRESSIVE
51	};
52
53	enum CeltBlockSize {
54	CELT_BLOCK_120,
55	CELT_BLOCK_240,
56	CELT_BLOCK_480,
57	CELT_BLOCK_960,
58
59	CELT_BLOCK_NB
60	};
61
62	typedef struct CeltBlock {
63	float energy[CELT_MAX_BANDS];
64	float lin_energy[CELT_MAX_BANDS];
65	float error_energy[CELT_MAX_BANDS];
66	float prev_energy[2][CELT_MAX_BANDS];
67
68	uint8_t collapse_masks[CELT_MAX_BANDS];
69
70	int band_bins[CELT_MAX_BANDS]; /* MDCT bins per band */
71	float *band_coeffs[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)[120];
79	DECLARE_ALIGNED(32, float, samples)[CELT_MAX_FRAME_SIZE];
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	int channels;
99	int output_channels;
100
101	enum CeltBlockSize size;
102	int start_band;
103	int end_band;
104	int coded_bands;
105	int transient;
106	int intra;
107	int pfilter;
108	int skip_band_floor;
109	int tf_select;
110	int alloc_trim;
111	int alloc_boost[CELT_MAX_BANDS];
112	int blocks; /* number of iMDCT blocks in the frame, depends on transient */
113	int blocksize; /* size of each block */
114	int silence; /* Frame is filled with silence */
115	int anticollapse_needed; /* Whether to expect an anticollapse bit */
116	int anticollapse; /* Encoded anticollapse bit */
117	int intensity_stereo;
118	int dual_stereo;
119	int flushed;
120	uint32_t seed;
121	enum CeltSpread spread;
122
123	/* Bit allocation */
124	int framebits;
125	int remaining;
126	int remaining2;
127	int caps [CELT_MAX_BANDS];
128	int fine_bits [CELT_MAX_BANDS];
129	int fine_priority[CELT_MAX_BANDS];
130	int pulses [CELT_MAX_BANDS];
131	int tf_change [CELT_MAX_BANDS];
132
133	DECLARE_ALIGNED(32, float, scratch)[22 * 8]; // MAX(ff_celt_freq_range) * 1<<CELT_MAX_LOG_BLOCKS
134	};
135
136	/* LCG for noise generation */
137	static av_always_inline uint32_t celt_rng(CeltFrame *f)
138	{
139	f->seed = 1664525 * f->seed + 1013904223;
140	return f->seed;
141	}
142
143	static av_always_inline void celt_renormalize_vector(float *X, int N, float gain)
144	{
145	int i;
146	float g = 1e-15f;
147	for (i = 0; i < N; i++)
148	g += X[i] * X[i];
149	g = gain / sqrtf(g);
150
151	for (i = 0; i < N; i++)
152	X[i] *= g;
153	}
154
155	int ff_celt_init(AVCodecContext *avctx, CeltFrame **f, int output_channels);
156
157	void ff_celt_free(CeltFrame **f);
158
159	void ff_celt_flush(CeltFrame *f);
160
161	int ff_celt_decode_frame(CeltFrame *f, OpusRangeCoder *rc, float **output,
162	int coded_channels, int frame_size, int startband, int endband);
163
164	#endif /* AVCODEC_OPUS_CELT_H */
165