path: root/libavcodec/opus_rc.h (plain)
blob: 821eeadd6ed5aef5fd9e9adf0509daeb70871db1

1	/*
2	* Copyright (c) 2012 Andrew D'Addesio
3	* Copyright (c) 2013-2014 Mozilla Corporation
4	* Copyright (c) 2017 Rostislav Pehlivanov <atomnuker@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	#ifndef AVCODEC_OPUS_RC_H
24	#define AVCODEC_OPUS_RC_H
25
26	#include <stdint.h>
27	#include "get_bits.h"
28
29	#define OPUS_MAX_PACKET_SIZE 1275
30
31	#define opus_ilog(i) (av_log2(i) + !!(i))
32
33	typedef struct RawBitsContext {
34	const uint8_t *position;
35	uint32_t bytes;
36	uint32_t cachelen;
37	uint32_t cacheval;
38	} RawBitsContext;
39
40	typedef struct OpusRangeCoder {
41	GetBitContext gb;
42	RawBitsContext rb;
43	uint32_t range;
44	uint32_t value;
45	uint32_t total_bits;
46
47	/* Encoder */
48	uint8_t buf[OPUS_MAX_PACKET_SIZE + 12]; /* memcpy vs (memmove + overreading) */
49	uint8_t *rng_cur; /* Current range coded byte */
50	int ext; /* Awaiting propagation */
51	int rem; /* Carryout flag */
52
53	/* Encoding stats */
54	int waste;
55	} OpusRangeCoder;
56
57	/**
58	* CELT: estimate bits of entropy that have thus far been consumed for the
59	* current CELT frame, to integer and fractional (1/8th bit) precision
60	*/
61	static av_always_inline uint32_t opus_rc_tell(const OpusRangeCoder *rc)
62	{
63	return rc->total_bits - av_log2(rc->range) - 1;
64	}
65
66	static av_always_inline uint32_t opus_rc_tell_frac(const OpusRangeCoder *rc)
67	{
68	uint32_t i, total_bits, rcbuffer, range;
69
70	total_bits = rc->total_bits << 3;
71	rcbuffer = av_log2(rc->range) + 1;
72	range = rc->range >> (rcbuffer-16);
73
74	for (i = 0; i < 3; i++) {
75	int bit;
76	range = range * range >> 15;
77	bit = range >> 16;
78	rcbuffer = rcbuffer << 1 | bit;
79	range >>= bit;
80	}
81
82	return total_bits - rcbuffer;
83	}
84
85	uint32_t ff_opus_rc_dec_cdf(OpusRangeCoder *rc, const uint16_t *cdf);
86	void ff_opus_rc_enc_cdf(OpusRangeCoder *rc, int val, const uint16_t *cdf);
87
88	uint32_t ff_opus_rc_dec_log(OpusRangeCoder *rc, uint32_t bits);
89	void ff_opus_rc_enc_log(OpusRangeCoder *rc, int val, uint32_t bits);
90
91	uint32_t ff_opus_rc_dec_uint_step(OpusRangeCoder *rc, int k0);
92	void ff_opus_rc_enc_uint_step(OpusRangeCoder *rc, uint32_t val, int k0);
93
94	uint32_t ff_opus_rc_dec_uint_tri(OpusRangeCoder *rc, int qn);
95	void ff_opus_rc_enc_uint_tri(OpusRangeCoder *rc, uint32_t k, int qn);
96
97	uint32_t ff_opus_rc_dec_uint(OpusRangeCoder *rc, uint32_t size);
98	void ff_opus_rc_enc_uint(OpusRangeCoder *rc, uint32_t val, uint32_t size);
99
100	uint32_t ff_opus_rc_get_raw(OpusRangeCoder *rc, uint32_t count);
101	void ff_opus_rc_put_raw(OpusRangeCoder *rc, uint32_t val, uint32_t count);
102
103	int ff_opus_rc_dec_laplace(OpusRangeCoder *rc, uint32_t symbol, int decay);
104	void ff_opus_rc_enc_laplace(OpusRangeCoder *rc, int *value, uint32_t symbol, int decay);
105
106	int ff_opus_rc_dec_init(OpusRangeCoder *rc, const uint8_t *data, int size);
107	void ff_opus_rc_dec_raw_init(OpusRangeCoder *rc, const uint8_t *rightend, uint32_t bytes);
108
109	void ff_opus_rc_enc_end(OpusRangeCoder *rc, uint8_t *dst, int size);
110	void ff_opus_rc_enc_init(OpusRangeCoder *rc);
111
112	#endif /* AVCODEC_OPUS_RC_H */
113