Use USB webcam

When I tried to run with USB webcam, there was an error.

2020-05-12 23:15:27.371447: I tensorflow/stream_executor/platform/default/] Successfully opened dynamic library
[ WARN:0] global /home/nvidia/host/build_opencv/nv_opencv/modules/videoio/src/cap_gstreamer.cpp (1757) handleMessage OpenCV | GStreamer warning: Embedded video playback halted; module v4l2src0 reported: Internal data stream error.
[ WARN:0] global /home/nvidia/host/build_opencv/nv_opencv/modules/videoio/src/cap_gstreamer.cpp (886) open OpenCV | GStreamer warning: unable to start pipeline
[ WARN:0] global /home/nvidia/host/build_opencv/nv_opencv/modules/videoio/src/cap_gstreamer.cpp (480) isPipelinePlaying OpenCV | GStreamer warning: GStreamer: pipeline have not been created
Failed to open camera!

I used these commands
python3 --model ssd_mobilenet_v2_face --usb --vid 0

What’s the problem?

I use this repository.

would try to run usb camera with /dev/video0.
But if you have a CSI onboard camera, it should be /dev/video0, so your usb cam may be /dev/video1, so you may just try --usb --vid 1