static short[] shortArrayFromBytes(byte[] a) {
  ret shortArrayFromBytes(a, 0, l(a));
}

static short[] shortArrayFromBytes(byte[] a, int from, int to) {
  short[] b = new short[(to-from)/2];
  for (int i = 0; i < b.length; i++)
    b[i] = shortFromBytes(a, from+i*2);
  ret b;
}