问题 warning: Error opening file (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:901) warning: 1.avi (/build/opencv/modules/videoio/src/cap_ffmpeg_impl.hpp:902)
解决： 修改代码：cv2.VideoCapture('1.avi')
改为：cv2.VideoCapture(0, cv2.CAP_DSHOW)
学习 cv2.VideoCapture(0, cv2.CAP_DSHOW) 参数“0”打开电脑摄像头cam = cv2.VideoCapture(1, cv2.CAP_DSHOW) 参数“1”打开外接摄像头
