OpenCV学习笔记 - Video Analysis - 录制视频

录制视频

使用自带摄像头录制一段5s的短视频

error & solution

fourcc1 = cv2.CV_FOURCC('m', 'p', '', 'v')

在实践过程中，运行这一行时报错：

原因分析
在opencv3中，已将部分函数名进行了修改，因此通常情况下不能直接使用旧版opencv的函数接口。所以，这里使用cv2.cv.CV_FOURCC()或cv2.CV_FOURCC()会报错。
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解决办法
将cv2.CV_FOURCC替换为cv2.VideoWriter_fourcc，以下两种方式均可以:

• fourcc = cv2.VideoWriter_fourcc('X','V','I','D')
• fourcc = cv2.VideoWriter_fourcc(*'XVID')

python版关键代码

 def write_video():
     cap = cv2.VideoCapture(0)
     # get first frame from camera to know frame size and type
     ret, frame = cap.read()
     rows, cols, channels = frame.shape

     # fourcc = cv2.CV_FOURCC('m', 'p', '4', 'v')          # error!
     # fourcc = cv2.VideoWriter_fourcc('m', 'p', '4', 'v') # ok!
     fourcc = cv2.VideoWriter_fourcc(*'XVID')              # another feasible way!

     my_writer = cv2.VideoWriter('MyOutput30.avi', fourcc, 10, (cols, rows))

     fps = 30
     seconds = 5  # 设置录制时间(秒)
     frames_remaining = seconds * fps

     while ret and frames_remaining > 0:
         ret, frame = cap.read()
         my_writer.write(frame)
         frames_remaining -= 1

Reference

• https://stackoverflow.com/questions/15584608/python-opencv2-cv2-cv-fourcc-not-working-with-videowriter
• http://blog.csdn.net/superdont/article/details/26259727