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 */
opus_rc_tell(const OpusRangeCoder * rc)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
opus_rc_tell_frac(const OpusRangeCoder * rc)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 #define OPUS_RC_CHECKPOINT_UPDATE(rc) \
113 rc_rollback_bits = opus_rc_tell_frac(rc); \
114 rc_rollback_ctx = *rc
115
116 #define OPUS_RC_CHECKPOINT_SPAWN(rc) \
117 uint32_t rc_rollback_bits = opus_rc_tell_frac(rc); \
118 OpusRangeCoder rc_rollback_ctx = *rc \
119
120 #define OPUS_RC_CHECKPOINT_BITS(rc) \
121 (opus_rc_tell_frac(rc) - rc_rollback_bits)
122
123 #define OPUS_RC_CHECKPOINT_ROLLBACK(rc) \
124 memcpy(rc, &rc_rollback_ctx, sizeof(OpusRangeCoder)); \
125
126 #endif /* AVCODEC_OPUS_RC_H */
127