Record a Webcam video with python

Question

I am trying to capture a video from a webcam stream. The python logic is

If button is pressed, store the current stream until I press the stop button.

Note : I am using OpenCV to stream a webcam video inside a wxPython window.

  def record(self, evt):
      cap = cv2.VideoCapture(0)

      # Define the codec and create VideoWriter object
      fourcc = cv2.VideoWriter_fourcc(*'XVID')
      out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))

I have tried the above code but it only stores 5.54kb file in the output dirctory?

How to do it?

Answer 1

you have set up a video writer object by

out = cv2.VideoWriter('output.avi',fourcc, 20.0, (640,480))

but you have not used write method to write the video frame buffer.

To do it, you need to call write method of the writer object that you instantiated by:

success, buf = cap.read()
out.write(buf)

This has to be put in a loop or be called by wx.Timer, otherwise only one frame will be saved.

finally, when you are done with streaming, do out.release() to close the video file.