FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/g722.c
Date: 2021-09-23 20:34:37
Exec Total Coverage
Lines: 51 51 100.0%
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1 /*
2 * G.722 ADPCM audio encoder/decoder
3 *
4 * Copyright (c) CMU 1993 Computer Science, Speech Group
5 * Chengxiang Lu and Alex Hauptmann
6 * Copyright (c) 2005 Steve Underwood <steveu at coppice.org>
7 * Copyright (c) 2009 Kenan Gillet
8 * Copyright (c) 2010 Martin Storsjo
9 *
10 * This file is part of FFmpeg.
11 *
12 * FFmpeg is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU Lesser General Public
14 * License as published by the Free Software Foundation; either
15 * version 2.1 of the License, or (at your option) any later version.
16 *
17 * FFmpeg is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * Lesser General Public License for more details.
21 *
22 * You should have received a copy of the GNU Lesser General Public
23 * License along with FFmpeg; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 */
26
27 /**
28 * @file
29 * G.722 ADPCM audio codec
30 *
31 * This G.722 decoder is a bit-exact implementation of the ITU G.722
32 * specification for all three specified bitrates - 64000bps, 56000bps
33 * and 48000bps. It passes the ITU tests.
34 *
35 * @note For the 56000bps and 48000bps bitrates, the lowest 1 or 2 bits
36 * respectively of each byte are ignored.
37 */
38
39 #include "mathops.h"
40 #include "g722.h"
41
42 static const int8_t sign_lookup[2] = { -1, 1 };
43
44 static const int16_t inv_log2_table[32] = {
45 2048, 2093, 2139, 2186, 2233, 2282, 2332, 2383,
46 2435, 2489, 2543, 2599, 2656, 2714, 2774, 2834,
47 2896, 2960, 3025, 3091, 3158, 3228, 3298, 3371,
48 3444, 3520, 3597, 3676, 3756, 3838, 3922, 4008
49 };
50 static const int16_t high_log_factor_step[2] = { 798, -214 };
51 const int16_t ff_g722_high_inv_quant[4] = { -926, -202, 926, 202 };
52 /**
53 * low_log_factor_step[index] == wl[rl42[index]]
54 */
55 static const int16_t low_log_factor_step[16] = {
56 -60, 3042, 1198, 538, 334, 172, 58, -30,
57 3042, 1198, 538, 334, 172, 58, -30, -60
58 };
59 const int16_t ff_g722_low_inv_quant4[16] = {
60 0, -2557, -1612, -1121, -786, -530, -323, -150,
61 2557, 1612, 1121, 786, 530, 323, 150, 0
62 };
63 const int16_t ff_g722_low_inv_quant6[64] = {
64 -17, -17, -17, -17, -3101, -2738, -2376, -2088,
65 -1873, -1689, -1535, -1399, -1279, -1170, -1072, -982,
66 -899, -822, -750, -682, -618, -558, -501, -447,
67 -396, -347, -300, -254, -211, -170, -130, -91,
68 3101, 2738, 2376, 2088, 1873, 1689, 1535, 1399,
69 1279, 1170, 1072, 982, 899, 822, 750, 682,
70 618, 558, 501, 447, 396, 347, 300, 254,
71 211, 170, 130, 91, 54, 17, -54, -17
72 };
73
74 542892 static inline void s_zero(int cur_diff, struct G722Band *band)
75 {
76 542892 int s_zero = 0;
77
78 #define ACCUM(k, x, d) do { \
79 int tmp = x; \
80 band->zero_mem[k] = ((band->zero_mem[k] * 255) >> 8) + \
81 d*((band->diff_mem[k]^cur_diff) < 0 ? -128 : 128); \
82 band->diff_mem[k] = tmp; \
83 s_zero += (tmp * band->zero_mem[k]) >> 15; \
84 } while (0)
85
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542892 if (cur_diff) {
86
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478418 ACCUM(5, band->diff_mem[4], 1);
87
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478418 ACCUM(4, band->diff_mem[3], 1);
88
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478418 ACCUM(3, band->diff_mem[2], 1);
89
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478418 ACCUM(2, band->diff_mem[1], 1);
90
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478418 ACCUM(1, band->diff_mem[0], 1);
91
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478418 ACCUM(0, cur_diff * 2, 1);
92 } else {
93 64474 ACCUM(5, band->diff_mem[4], 0);
94 64474 ACCUM(4, band->diff_mem[3], 0);
95 64474 ACCUM(3, band->diff_mem[2], 0);
96 64474 ACCUM(2, band->diff_mem[1], 0);
97 64474 ACCUM(1, band->diff_mem[0], 0);
98 64474 ACCUM(0, cur_diff * 2, 0);
99 }
100 #undef ACCUM
101 542892 band->s_zero = s_zero;
102 542892 }
103
104 /**
105 * adaptive predictor
106 *
107 * @param cur_diff the dequantized and scaled delta calculated from the
108 * current codeword
109 */
110 542892 static void do_adaptive_prediction(struct G722Band *band, const int cur_diff)
111 {
112 int sg[2], limit, cur_qtzd_reconst;
113
114 542892 const int cur_part_reconst = band->s_zero + cur_diff < 0;
115
116 542892 sg[0] = sign_lookup[cur_part_reconst != band->part_reconst_mem[0]];
117 542892 sg[1] = sign_lookup[cur_part_reconst == band->part_reconst_mem[1]];
118 542892 band->part_reconst_mem[1] = band->part_reconst_mem[0];
119 542892 band->part_reconst_mem[0] = cur_part_reconst;
120
121 542892 band->pole_mem[1] = av_clip((sg[0] * av_clip(band->pole_mem[0], -8191, 8191) >> 5) +
122 542892 (sg[1] * 128) + (band->pole_mem[1] * 127 >> 7), -12288, 12288);
123
124 542892 limit = 15360 - band->pole_mem[1];
125 542892 band->pole_mem[0] = av_clip(-192 * sg[0] + (band->pole_mem[0] * 255 >> 8), -limit, limit);
126
127 542892 s_zero(cur_diff, band);
128
129 542892 cur_qtzd_reconst = av_clip_int16((band->s_predictor + cur_diff) * 2);
130 542892 band->s_predictor = av_clip_int16(band->s_zero +
131 542892 (band->pole_mem[0] * cur_qtzd_reconst >> 15) +
132 542892 (band->pole_mem[1] * band->prev_qtzd_reconst >> 15));
133 542892 band->prev_qtzd_reconst = cur_qtzd_reconst;
134 542892 }
135
136 542892 static inline int linear_scale_factor(const int log_factor)
137 {
138 542892 const int wd1 = inv_log2_table[(log_factor >> 6) & 31];
139 542892 const int shift = log_factor >> 11;
140
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542892 return shift < 0 ? wd1 >> -shift : wd1 << shift;
141 }
142
143 271446 void ff_g722_update_low_predictor(struct G722Band *band, const int ilow)
144 {
145 271446 do_adaptive_prediction(band,
146 271446 band->scale_factor * ff_g722_low_inv_quant4[ilow] >> 10);
147
148 // quantizer adaptation
149 271446 band->log_factor = av_clip((band->log_factor * 127 >> 7) +
150 271446 low_log_factor_step[ilow], 0, 18432);
151 271446 band->scale_factor = linear_scale_factor(band->log_factor - (8 << 11));
152 271446 }
153
154 271446 void ff_g722_update_high_predictor(struct G722Band *band, const int dhigh,
155 const int ihigh)
156 {
157 271446 do_adaptive_prediction(band, dhigh);
158
159 // quantizer adaptation
160 271446 band->log_factor = av_clip((band->log_factor * 127 >> 7) +
161 271446 high_log_factor_step[ihigh&1], 0, 22528);
162 271446 band->scale_factor = linear_scale_factor(band->log_factor - (10 << 11));
163 271446 }
164