--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Meerwald-dir/gen_frid2_sig.c	Fri Dec 20 13:08:59 2024 +0100
@@ -0,0 +1,150 @@
+#include "wm.h"
+#include "signature.h"
+
+char *progname;
+
+void usage(void) {
+  fprintf(stderr, "usage: %s [-a n] [-g n] [-o file] [-s n] file\n\n", progname);
+  fprintf(stderr, "\t-a n\t\talpha factor (default 0.25)\n");
+  fprintf(stderr, "\t-g n\t\tgamma factor (default 1.0)\n");
+  fprintf(stderr, "\t-s n\t\tseed (default 0)\n");
+  fprintf(stderr, "\t-h\t\tprint usage\n");
+  fprintf(stderr, "\t-n n\t\twatermark length (default 100)\n");
+  fprintf(stderr, "\t-o file\t\toutput file\n");
+  fprintf(stderr, "\t-s file\t\tuse signature file's embedding information\n");
+  fprintf(stderr, "\t-S n\t\tseed\n");
+  exit(0);
+}
+
+int main(int argc, char *argv[]) {
+  FILE *in = stdin;
+  FILE *out = stdout;
+  FILE *sig = NULL;
+
+  char output_name[MAXPATHLEN] = "(stdout)";
+  char input_name[MAXPATHLEN] = "(stdin)";
+  char signature_name[MAXPATHLEN];
+
+  int c;
+  int i;
+  int n = 100, nb;
+  double a = 0.25;
+  double g = 1.0;
+  int s = 0;
+
+  progname = argv[0];
+
+#ifdef __EMX__
+  _fsetmode(in, "b");
+  _fsetmode(out, "b");
+#endif
+
+  while ((c = getopt(argc, argv, "a:g:h?n:o:s:S:")) != EOF) {
+    switch (c) {
+      case 'a':
+        a = atof(optarg);
+        if (a <= 0.0) {
+          fprintf(stderr, "%s: alpha factor %f out of range\n", progname, a);
+          exit(1);
+        }
+        break;
+      case 'g':
+        g = atof(optarg);
+        if (g <= 0.0) {
+          fprintf(stderr, "%s: gamma factor %f out of range\n", progname, a);
+          exit(1);
+        }
+        break;
+      case 'h':
+      case '?':
+        usage();
+        break;
+      case 'n':
+        n = atoi(optarg);
+        if (n < 1 || n > 1000) {
+          fprintf(stderr, "%s: watermark length %d out of range\n", progname, n);
+          exit(1);
+        }
+        break;
+      case 'o':
+        if ((out = fopen(optarg, "w")) == NULL) {
+          fprintf(stderr, "%s: unable to open output file %s\n", progname, optarg);
+          exit(1);
+        }
+        strcpy(output_name, optarg);
+        break;
+      case 's':   
+        if ((sig = fopen(optarg, "r")) == NULL) {
+          fprintf(stderr, "%s: unable to open signature file %s\n", progname, optarg);
+          exit(1);
+        }
+        strcpy(signature_name, optarg);
+        break;
+      case 'S':
+        s = atoi(optarg);
+        break;
+    }
+  }
+
+  argc -= optind;
+  argv += optind;
+
+  if (argc > 1) {
+    usage();
+    exit(1);
+  }
+
+  if (argc == 1 && *argv[0] != '-') {
+    if ((in = fopen(argv[0], "rb")) == NULL) {
+      fprintf(stderr, "%s: unable to open input file %s\n", progname, argv[0]);
+      exit(1);   
+    }
+    else
+      strcpy(input_name, argv[0]);
+  }
+
+  if (!s)
+    s = time(NULL) * getpid();
+  srandom(s);
+
+  if (sig) {
+    char line[128];
+    fgets(line, sizeof(line), sig);
+    if (strspn(line, "FR2SG") >= 5) {
+    }
+    else {
+      fprintf(stderr, "%s: invalid signature file %s\n", progname, signature_name);
+      exit(1);
+    }
+    fclose(sig);
+  }
+
+  if (n > 0) {   
+    nb = fread(signature, sizeof(char), i = NBITSTOBYTES(n), in);
+    if (nb < i) {
+      fprintf(stderr, "%s: failed to read all %d signature bits from %s\n", progname, n, input_name);
+      exit(1);
+    }
+  }
+  else {
+    if (fscanf(in, "%128[^\n\r]", signature) == EOF) {
+      fprintf(stderr, "%s: failed to read signature bits from %s\n", progname, input_name);
+      exit(1);
+    }
+    nb = strlen(signature);
+    n = NBYTESTOBITS(nb);
+    fprintf(stderr, "%s: got %d signature bits\n", progname, n);
+  }
+
+  fprintf(out, "FR2SG\n");
+  fprintf(out, "%d\n", n);
+  fprintf(out, "%f\n", a);
+  fprintf(out, "%f\n", g);
+  fprintf(out, "%d\n", s);
+  fwrite(signature, sizeof(char), nb, out);
+  fprintf(out, "\n");
+
+  fclose(out);
+
+  exit(0);
+}