1 /*
2 * Copyright (C) 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 #include <assert.h>
17 #include <inttypes.h>
18 #include <math.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <vector>
23
24 template <typename T, typename A = float>
getSignalNoise(FILE * finp,FILE * fref)25 std::pair<A, A> getSignalNoise(FILE *finp, FILE *fref) {
26 constexpr size_t framesize = 256;
27 std::vector<T> in(framesize);
28 std::vector<T> ref(framesize);
29 A signal{};
30 A noise{};
31
32 for (;;) {
33 size_t read_samples_in = fread(&in[0], sizeof(T), framesize, finp);
34 const size_t read_samples_ref = fread(&ref[0], sizeof(T), framesize, fref);
35 if (read_samples_in != read_samples_ref) {
36 printf("file sizes do not match (last %zu %zu)", read_samples_in, read_samples_ref);
37 read_samples_in = std::min(read_samples_in, read_samples_ref);
38 }
39 if (read_samples_in == 0) {
40 return { signal, noise };
41 }
42 for (size_t i = 0; i < read_samples_in; ++i) {
43 const A value(ref[i]);
44 const A diff(A(in[i]) - value);
45 signal += value * value;
46 noise += diff * diff;
47 }
48 }
49 }
50
printUsage()51 void printUsage() {
52 printf("\nUsage: ");
53 printf("\n snr <ref_file> <test_file> [options]\n");
54 printf("\nwhere, \n <ref_file> is the reference file name");
55 printf("\n on which will be taken as pure signal");
56 printf("\n <test_file> is test file for snr calculation");
57 printf("\n and options are mentioned below");
58 printf("\n");
59 printf("\n -pcm_format:<pcm format of input files>");
60 printf("\n 0 - 16 bit pcm");
61 printf("\n 1 - 32 bit float");
62 printf("\n default 0");
63 printf("\n -thr:<threshold value>");
64 printf("\n default - negative infinity\n\n");
65 }
66
main(int argc,const char * argv[])67 int main(int argc, const char *argv[]) {
68 if (argc < 3) {
69 printUsage();
70 return -1;
71 }
72 int pcm_format = 0;
73 float thr = - std::numeric_limits<float>::infinity();
74 FILE *fref = fopen(argv[1], "rb");
75 FILE *finp = fopen(argv[2], "rb");
76 for (int i = 3; i < argc; i++) {
77 if (!strncmp(argv[i], "-pcm_format:", 12)) {
78 pcm_format = atoi(argv[i] + 12);
79 } else if (!strncmp(argv[i], "-thr:", 5)) {
80 thr = atof(argv[i] + 5);
81 }
82 }
83 if (finp == nullptr || fref == nullptr) {
84 printf("\nError: missing input/reference files\n");
85 return -1;
86 }
87 int ret = EXIT_SUCCESS;
88 auto sn = pcm_format == 0
89 ? getSignalNoise<short>(finp, fref)
90 : getSignalNoise<float>(finp, fref);
91 if (sn.first > 0.f && sn.second > 0.f) {
92 float snr = 10.f * log(sn.first / sn.second);
93 // compare the measured snr value with threshold
94 if (snr < thr) {
95 printf("%.6f less than threshold %.6f\n", snr, thr);
96 ret = EXIT_FAILURE;
97 } else {
98 printf("%.6f\n", snr);
99 }
100 }
101 fclose(finp);
102 fclose(fref);
103
104 return ret;
105 }
106