今天需要寫一段程式碼，呼叫攝像頭並儲存視訊。首先是說一下環境配置

1. Below Python packages are to be downloaded and installed to their default locations.

   1.2. Numpy.

   1.3. Matplotlib (Matplotlib is optional, but recommended since we use it a lot in our tutorials).

2. Install all packages into their default locations. Python will be installed to C:/Python27/

   .

3. After installation, open Python IDLE. Enter import numpy and make sure Numpy is working fine.

4. Download latest OpenCV release from sourceforge site and double-click to extract it.

7. Goto opencv/build/python/2.7 folder.

8. Copy cv2.pyd to C:/Python27/lib/site-packages.

9. Open Python IDLE and type following codes in Python terminal.

   >>> import cv2
   >>> print cv2.__version__

點選以上內容的連結https://docs.opencv.org/3.0-beta/doc/py_tutorials/py_setup/py_setup_in_windows/py_setup_in_windows.html，點選python、Numpy和Matplotlib，下載對應的安裝程式，這裡需要注意的是，openCV版本較多，如果版本不匹配會報錯。遇到版本不同的情況可以修改numpy的版本，如：pip  install -U numpy或者修改openCV的版本。由於我的電腦上裝有多個版本python，不能直接用pip，需要確認python中的scripts的路徑已經配置到環境變數中，再使用python -m pip install -U numpy。

以上都沒問題後，執行以下程式碼就可以看到可以錄製視訊了。

global now_time
cap = cv2.VideoCapture(Con_info.camera_No[0])
cap.set(4, 720)
fourcc = cv2.VideoWriter_fourcc(*"CVID")
arg1 = os.getcwd()+'//'+'video//'
print arg1
out = cv2.VideoWriter(arg1+ str(i) + '.avi', fourcc, 3, (640, 480))
while True:
    now_time = time.time()
    if now_time - start_time > 3*60*60:
        win32api.keybd_event(97, 0, 0, 0)
        start_time = now_time
    ret, frame = cap.read()  # 獲取影象
    frame = cv2.flip(frame, 1)  # 在幀上進行操作1
    cv2.imshow("frame", frame)  # 顯示幀
    out.write(frame)  # 儲存視訊1
    if cv2.waitKey(1) == ord('1'):  # 按下‘1’退出
        break
cap.release()
out.release()
cv2.destroyAllWindows()