FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavutil/tests/lfg.c
Date: 2024-11-20 23:03:26
Exec Total Coverage
Lines: 62 66 93.9%
Functions: 2 2 100.0%
Branches: 22 28 78.6%
Line Branch Exec Source
1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #include "libavutil/log.h"
20 #include "libavutil/mem.h"
21 #include "libavutil/timer.h"
22 #include "libavutil/lfg.h"
23
24 static const double Z_TABLE[31][10] = {
25 {0.5000, 0.5040, 0.5080, 0.5120, 0.5160, 0.5199, 0.5239, 0.5279, 0.5319, 0.5359},
26 {0.5398, 0.5438, 0.5478, 0.5517, 0.5557, 0.5596, 0.5636, 0.5675, 0.5714, 0.5753},
27 {0.5793, 0.5832, 0.5871, 0.5910, 0.5948, 0.5987, 0.6026, 0.6064, 0.6103, 0.6141},
28 {0.6179, 0.6217, 0.6255, 0.6293, 0.6331, 0.6368, 0.6406, 0.6443, 0.6480, 0.6517},
29 {0.6554, 0.6591, 0.6628, 0.6664, 0.6700, 0.6736, 0.6772, 0.6808, 0.6844, 0.6879},
30 {0.6915, 0.6950, 0.6985, 0.7019, 0.7054, 0.7088, 0.7123, 0.7157, 0.7190, 0.7224},
31 {0.7257, 0.7291, 0.7324, 0.7357, 0.7389, 0.7422, 0.7454, 0.7486, 0.7517, 0.7549},
32 {0.7580, 0.7611, 0.7642, 0.7673, 0.7704, 0.7734, 0.7764, 0.7794, 0.7823, 0.7852},
33 {0.7881, 0.7910, 0.7939, 0.7967, 0.7995, 0.8023, 0.8051, 0.8078, 0.8106, 0.8133},
34 {0.8159, 0.8186, 0.8212, 0.8238, 0.8264, 0.8289, 0.8315, 0.8340, 0.8365, 0.8389},
35 {0.8413, 0.8438, 0.8461, 0.8485, 0.8508, 0.8531, 0.8554, 0.8577, 0.8599, 0.8621},
36 {0.8643, 0.8665, 0.8686, 0.8708, 0.8729, 0.8749, 0.8770, 0.8790, 0.8810, 0.8830},
37 {0.8849, 0.8869, 0.8888, 0.8907, 0.8925, 0.8944, 0.8962, 0.8980, 0.8997, 0.9015},
38 {0.9032, 0.9049, 0.9066, 0.9082, 0.9099, 0.9115, 0.9131, 0.9147, 0.9162, 0.9177},
39 {0.9192, 0.9207, 0.9222, 0.9236, 0.9251, 0.9265, 0.9279, 0.9292, 0.9306, 0.9319},
40 {0.9332, 0.9345, 0.9357, 0.9370, 0.9382, 0.9394, 0.9406, 0.9418, 0.9429, 0.9441},
41 {0.9452, 0.9463, 0.9474, 0.9484, 0.9495, 0.9505, 0.9515, 0.9525, 0.9535, 0.9545},
42 {0.9554, 0.9564, 0.9573, 0.9582, 0.9591, 0.9599, 0.9608, 0.9616, 0.9625, 0.9633},
43 {0.9641, 0.9649, 0.9656, 0.9664, 0.9671, 0.9678, 0.9686, 0.9693, 0.9699, 0.9706},
44 {0.9713, 0.9719, 0.9726, 0.9732, 0.9738, 0.9744, 0.9750, 0.9756, 0.9761, 0.9767},
45 {0.9772, 0.9778, 0.9783, 0.9788, 0.9793, 0.9798, 0.9803, 0.9808, 0.9812, 0.9817},
46 {0.9821, 0.9826, 0.9830, 0.9834, 0.9838, 0.9842, 0.9846, 0.9850, 0.9854, 0.9857},
47 {0.9861, 0.9864, 0.9868, 0.9871, 0.9875, 0.9878, 0.9881, 0.9884, 0.9887, 0.9890},
48 {0.9893, 0.9896, 0.9898, 0.9901, 0.9904, 0.9906, 0.9909, 0.9911, 0.9913, 0.9916},
49 {0.9918, 0.9920, 0.9922, 0.9925, 0.9927, 0.9929, 0.9931, 0.9932, 0.9934, 0.9936},
50 {0.9938, 0.9940, 0.9941, 0.9943, 0.9945, 0.9946, 0.9948, 0.9949, 0.9951, 0.9952},
51 {0.9953, 0.9955, 0.9956, 0.9957, 0.9959, 0.9960, 0.9961, 0.9962, 0.9963, 0.9964},
52 {0.9965, 0.9966, 0.9967, 0.9968, 0.9969, 0.9970, 0.9971, 0.9972, 0.9973, 0.9974},
53 {0.9974, 0.9975, 0.9976, 0.9977, 0.9977, 0.9978, 0.9979, 0.9979, 0.9980, 0.9981},
54 {0.9981, 0.9982, 0.9982, 0.9983, 0.9984, 0.9984, 0.9985, 0.9985, 0.9986, 0.9986},
55 {0.9987, 0.9987, 0.9987, 0.9988, 0.9988, 0.9989, 0.9989, 0.9989, 0.9990, 0.9990} };
56
57 // Inverse cumulative distribution function
58 1998 static double inv_cdf(double u)
59 {
60 const double a[4] = { 2.50662823884,
61 -18.61500062529,
62 41.39119773534,
63 -25.44106049637};
64
65 const double b[4] = {-8.47351093090,
66 23.08336743743,
67 -21.06224101826,
68 3.13082909833};
69
70 const double c[9] = {0.3374754822726147,
71 0.9761690190917186,
72 0.1607979714918209,
73 0.0276438810333863,
74 0.0038405729373609,
75 0.0003951896511919,
76 0.0000321767881768,
77 0.0000002888167364,
78 0.0000003960315187};
79
80 double r;
81 1998 double x = u - 0.5;
82
83 // Beasley-Springer
84
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 1998 if (fabs(x) < 0.42) {
85
86 1680 double y = x * x;
87 1680 r = x * (((a[3]*y+a[2])*y+a[1])*y+a[0]) /
88 1680 ((((b[3]*y+b[2])*y+b[1])*y+b[0])*y+1.0);
89 }
90 else {// Moro
91 318 r = u;
92
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 318 if (x > 0.0)
93 159 r = 1.0 - u;
94 318 r = log(-log(r));
95 318 r = c[0] + r*(c[1]+r*(c[2]+r*(c[3]+r*(c[4]+r*(c[5]+r*(c[6]+
96 318 r*(c[7]+r*c[8])))))));
97
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 318 if (x < 0.0)
98 159 r = -r;
99 }
100
101 1998 return r;
102 }
103 1 int main(void)
104 {
105 1 int x = 0;
106 int i, j;
107 AVLFG state;
108 1 av_lfg_init(&state, 0xdeadbeef);
109
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 10001 for (j = 0; j < 10000; j++) {
110
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 6250000 for (i = 0; i < 624; i++) {
111 //av_log(NULL, AV_LOG_ERROR, "%X\n", av_lfg_get(&state));
112 6240000 x += av_lfg_get(&state);
113 }
114 }
115 1 av_log(NULL, AV_LOG_ERROR, "final value:%X\n", x);
116
117 /* BMG usage example */
118 {
119 1 double mean = 1000;
120 1 double stddev = 53;
121 1 double samp_mean = 0.0, samp_stddev = 0.0, QH = 0;
122 1 double Z, p_value = -1, tot_samp = 1000;
123 1 double *PRN_arr = av_malloc_array(tot_samp, sizeof(double));
124
125
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 1 if (!PRN_arr) {
126 ✗ fprintf(stderr, "failed to allocate memory!\n");
127 ✗ return 1;
128 }
129
130 1 av_lfg_init(&state, 42);
131
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 501 for (i = 0; i < tot_samp; i += 2) {
132 double bmg_out[2];
133 500 av_bmg_get(&state, bmg_out);
134 500 PRN_arr[i ] = bmg_out[0] * stddev + mean;
135 500 PRN_arr[i+1] = bmg_out[1] * stddev + mean;
136 500 samp_mean += PRN_arr[i] + PRN_arr[i+1];
137 500 samp_stddev += PRN_arr[i] * PRN_arr[i] + PRN_arr[i+1] * PRN_arr[i+1];
138 500 printf("PRN%d : %f\n"
139 "PRN%d : %f\n",
140 500 i, PRN_arr[i], i+1, PRN_arr[i+1]);
141 }
142 1 samp_mean /= tot_samp;
143 1 samp_stddev /= (tot_samp - 1);
144 1 samp_stddev -= (tot_samp * 1.0 / (tot_samp - 1))*samp_mean*samp_mean;
145 1 samp_stddev = sqrt(samp_stddev);
146 1 Z = (mean - samp_mean) / (stddev / sqrt(tot_samp));
147 {
148 1 int x, y, a, b, flag = 0;
149
150
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 1 if (Z < 0.0) {
151 1 flag = !flag;
152 1 Z = Z * -1.0;
153 }
154
155 1 a = (int)(Z * 100);
156 1 b = ((int)Z * 100);
157 1 x = Z * 10;
158
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 1 y = (b > 0) ? a % b : a;
159 1 y = y % 10;
160
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 1 if (x > 30 || y > 9) {
161 ✗ av_log(NULL, AV_LOG_INFO, "error: out of bounds! tried to access"
162 "Z_TABLE[%d][%d]\n", x, y);
163 ✗ goto SKIP;
164 }
165
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 1 p_value = flag ? 1 - Z_TABLE[x][y] : Z_TABLE[x][y];
166 }
167
168
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 1001 SKIP: for (i = 0; i < tot_samp; ++i) {
169
170
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 1000 if ( i < (tot_samp - 1)) {
171 double H_diff;
172 999 H_diff = inv_cdf((i + 2.0 - (3.0/8.0)) / (tot_samp + (1.0/4.0)));
173 999 H_diff -= inv_cdf((i + 1.0 - (3.0/8.0)) / (tot_samp + (1.0/4.0)));
174
175 999 QH += ((PRN_arr[i + 1] - PRN_arr[i]) / H_diff);
176 }
177 }
178 1 QH = 1.0 - QH / ((tot_samp - 1.0) * samp_stddev);
179
180 1 printf("sample mean : %f\n"
181 "true mean : %f\n"
182 "sample stddev: %f\n"
183 "true stddev : %f\n"
184 "z-score : %f\n"
185 "p-value : %f\n"
186 "QH[normality]: %f\n",
187 samp_mean, mean, samp_stddev, stddev, Z, p_value, QH);
188
189 1 av_freep(&PRN_arr);
190 }
191 1 return 0;
192 }
193