Graphs of Sine and Cosine · Hard problem

The wave drawn is $y = a\,sin\!\left(b(x - h)\right) + k$. From the graph and the equation $y = - 3 \cos{\left(4 x + \frac{3 \pi}{8} \right)}$, give the amplitude, the period, the midline $k$, and the horizontal shift $h$.