command = r"adb shell screencap -p"
proc = subprocess.Popen(shlex.split(command),stdout=subprocess.PIPE)
out = proc.stdout.read(30000000)
img = cv2.imdecode(out,cv2.IMREAD_COLOR)
if img is not None:
    cv2.imshow("",img)
    cv2.waitKey(0)
    cv2.destroyWindow("")

TypeError: buf is not a numpy array, neither a scalar