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
fsize(FILE * f)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
main(int argc,char ** argv)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 }
123