FFmpeg  4.4.5
audiomatch.c
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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 <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <math.h>
23 #include <inttypes.h>
24 
25 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
26 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
27 #define FFABS(a) ((a) >= 0 ? (a) : (-(a)))
28 
29 static int64_t fsize(FILE *f) {
30  int64_t end, pos = ftell(f);
31  fseek(f, 0, SEEK_END);
32  end = ftell(f);
33  fseek(f, pos, SEEK_SET);
34  return end;
35 }
36 
37 int main(int argc, char **argv) {
38  FILE *f[2];
39  int i, pos;
40  int siglen, datlen;
41  int bestpos = 0;
42  double bestc = 0;
43  double sigamp = 0;
44  int16_t *signal, *data;
45  int maxshift = 16384;
46 
47  if (argc < 3) {
48  printf("audiomatch <testfile> <reffile>\n");
49  printf("WAV headers are skipped automatically.\n");
50  return 1;
51  }
52 
53  f[0] = fopen(argv[1], "rb");
54  f[1] = fopen(argv[2], "rb");
55  if (!f[0] || !f[1]) {
56  fprintf(stderr, "Could not open input files.\n");
57  return 1;
58  }
59 
60  for (i = 0; i < 2; i++) {
61  uint8_t p[100];
62  if (fread(p, 1, 12, f[i]) != 12)
63  return 1;
64  if (!memcmp(p, "RIFF", 4) &&
65  !memcmp(p + 8, "WAVE", 4)) {
66  if (fread(p, 1, 8, f[i]) != 8)
67  return 1;
68  while (memcmp(p, "data", 4)) {
69  int s = p[4] | p[5] << 8 | p[6] << 16 | p[7] << 24;
70  fseek(f[i], s, SEEK_CUR);
71  if (fread(p, 1, 8, f[i]) != 8)
72  return 1;
73  }
74  } else {
75  fseek(f[i], -12, SEEK_CUR);
76  }
77  }
78 
79  datlen = fsize(f[0]) - ftell(f[0]);
80  siglen = fsize(f[1]) - ftell(f[1]);
81  data = malloc(datlen * sizeof(*data));
82  signal = malloc(siglen * sizeof(*signal));
83 
84  if (fread(data , 1, datlen, f[0]) != datlen)
85  goto read_fail;
86  if (fread(signal, 1, siglen, f[1]) != siglen)
87  goto read_fail;
88  datlen /= 2;
89  siglen /= 2;
90 
91  for (i = 0; i < siglen; i++) {
92  signal[i] = ((uint8_t*)(signal + i))[0] + 256*((uint8_t*)(signal + i))[1];
93  sigamp += signal[i] * signal[i];
94  }
95  for (i = 0; i < datlen; i++)
96  data[i] = ((uint8_t*)(data + i))[0] + 256*((uint8_t*)(data + i))[1];
97 
98  for (pos = 0; pos < maxshift; pos = pos < 0 ? -pos: -pos-1) {
99  int64_t c = 0;
100  int testlen = FFMIN(siglen, datlen-pos);
101  for (i = FFMAX(0, -pos); i < testlen; i++) {
102  int j = pos + i;
103  c += signal[i] * data[j];
104  }
105  if (FFABS(c) > sigamp * 0.94)
106  maxshift = FFMIN(maxshift, FFABS(pos)+32);
107  if (FFABS(c) > FFABS(bestc)) {
108  bestc = c;
109  bestpos = pos;
110  }
111  }
112  printf("presig: %d postsig:%d c:%7.4f lenerr:%d\n", bestpos, datlen - siglen - bestpos, bestc / sigamp, datlen - siglen);
113 
114  free(data);
115  free(signal);
116  return 0;
117 
118 read_fail:
119  free(data);
120  free(signal);
121  return 1;
122 }
uint8_t
#define FFMIN(a, b)
Definition: audiomatch.c:25
static int64_t fsize(FILE *f)
Definition: audiomatch.c:29
int main(int argc, char **argv)
Definition: audiomatch.c:37
#define FFMAX(a, b)
Definition: audiomatch.c:26
#define FFABS(a)
Definition: audiomatch.c:27
#define s(width, name)
Definition: cbs_vp9.c:257
#define f(width, name)
Definition: cbs_vp9.c:255
long long int64_t
Definition: coverity.c:34
int i
Definition: input.c:407
const char data[16]
Definition: mxf.c:142
unsigned int pos
Definition: spdifenc.c:412
static double c[64]