使用树莓派相机进行运动检测

Question

import numpy as np
import picamera
import picamera.array

class DetectMotion(picamera.array.PiMotionAnalysis):
    def analyze(self, a):
        a = np.sqrt(
            np.square(a['x'].astype(np.float)) +
            np.square(a['y'].astype(np.float))
            ).clip(0, 255).astype(np.uint8)
        # If there're more than 10 vectors with a magnitude greater
        # than 60, then say we've detected motion
        if (a > 60).sum() > 10:
            print('Motion detected!')
        else:
            print('No motion')

with picamera.PiCamera() as camera:
    with DetectMotion(camera) as output:
        camera.resolution = (640, 480)
        camera.start_recording(
              '/dev/null', format='h264', motion_output=output)
        camera.wait_recording(5)
        camera.stop_recording()

这是使用运动检测矢量的树莓派相机的。

如果此代码检测到运动，它将录制5秒钟的视频。我的问题是，如果它仍在检测运动，我想再次使此代码camera.wait_recording(5)。这意味着如果它检测到运动，则camera.wait_recording的值仍为5秒，如果未检测到运动，则camera.wait_recording的值将开始衰减。