early-access version 1432

externals/ffmpeg/tests/audiomatch.c

@@ -0,0 +1,114 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <inttypes.h>
+
+#define FFMIN(a,b) ((a) > (b) ? (b) : (a))
+#define FFMAX(a,b) ((a) > (b) ? (a) : (b))
+
+static int64_t fsize(FILE *f) {
+    int64_t end, pos = ftell(f);
+    fseek(f, 0, SEEK_END);
+    end = ftell(f);
+    fseek(f, pos, SEEK_SET);
+    return end;
+}
+
+int main(int argc, char **argv) {
+    FILE *f[2];
+    int i, pos;
+    int siglen, datlen;
+    int bestpos = 0;
+    double bestc = 0;
+    double sigamp = 0;
+    int16_t *signal, *data;
+    int maxshift = 16384;
+
+    if (argc < 3) {
+        printf("audiomatch <testfile> <reffile>\n");
+        printf("WAV headers are skipped automatically.\n");
+        return 1;
+    }
+
+    f[0] = fopen(argv[1], "rb");
+    f[1] = fopen(argv[2], "rb");
+    if (!f[0] || !f[1]) {
+        fprintf(stderr, "Could not open input files.\n");
+        return 1;
+    }
+
+    for (i = 0; i < 2; i++) {
+        uint8_t p[100];
+        if (fread(p, 1, 12, f[i]) != 12)
+            return 1;
+        if (!memcmp(p, "RIFF", 4) &&
+            !memcmp(p + 8, "WAVE", 4)) {
+            if (fread(p, 1, 8, f[i]) != 8)
+                return 1;
+            while (memcmp(p, "data", 4)) {
+                int s = p[4] | p[5] << 8 | p[6] << 16 | p[7] << 24;
+                fseek(f[i], s, SEEK_CUR);
+                if (fread(p, 1, 8, f[i]) != 8)
+                    return 1;
+            }
+        } else {
+            fseek(f[i], -12, SEEK_CUR);
+        }
+    }
+
+    datlen = fsize(f[0]) - ftell(f[0]);
+    siglen = fsize(f[1]) - ftell(f[1]);
+    data   = malloc(datlen * sizeof(*data));
+    signal = malloc(siglen * sizeof(*signal));
+
+    if (fread(data  , 1, datlen, f[0]) != datlen)
+        return 1;
+    if (fread(signal, 1, siglen, f[1]) != siglen)
+        return 1;
+    datlen /= 2;
+    siglen /= 2;
+
+    for (i = 0; i < siglen; i++) {
+        signal[i] = ((uint8_t*)(signal + i))[0] + 256*((uint8_t*)(signal + i))[1];
+        sigamp += signal[i] * signal[i];
+    }
+    for (i = 0; i < datlen; i++)
+        data[i] = ((uint8_t*)(data + i))[0] + 256*((uint8_t*)(data + i))[1];
+
+    for (pos = 0; pos < maxshift; pos = pos < 0 ? -pos: -pos-1) {
+        int64_t c = 0;
+        int testlen = FFMIN(siglen, datlen-pos);
+        for (i = FFMAX(0, -pos); i < testlen; i++) {
+            int j = pos + i;
+            c += signal[i] * data[j];
+        }
+        if (fabs(c) > sigamp * 0.94)
+            maxshift = FFMIN(maxshift, fabs(pos)+32);
+        if (fabs(c) > fabs(bestc)) {
+            bestc = c;
+            bestpos = pos;
+        }
+    }
+    printf("presig: %d postsig:%d c:%7.4f lenerr:%d\n", bestpos, datlen - siglen - bestpos, bestc / sigamp, datlen - siglen);
+
+    return 0;
+}