int CLASS canon_has_lowbits()
{
  uchar test[0x4000];
  int ret=1;
  unsigned i;

  fseek (ifp, 0, SEEK_SET);
  fread (test, 1, sizeof test, ifp);
  for (i=540; i < sizeof test - 1; i++)
    if (test[i] == 0xff) {
      if (test[i+1]) return 1;
      ret=0;
    }
  return ret;
}
int CLASS canon_has_lowbits()
{
  uchar test[0x4000];
  int ret=1;
  unsigned i;

  fseek (ifp, 0, SEEK_SET);
  fread (test, 1, sizeof test, ifp);
  for (i=540; i < sizeof test - 1; i++)
    if (test[i] == 0xff) {
      if (test[i+1]) return 1;
      ret=0;
    }
  return ret;
}