VideoIO: avformat_open_input error code -5

When I run the following code, the following error appears.

julia>t = VideoIO.get_camera_devices(ffmpeg, "dshow", "dummy")
julia>VideoIO.opencamera(t[1])
ERROR: Could not open USB2.0 HD UVC WebCam. avformat_open_input error code -5

Please ask how to solve this problem.