Question: I'm working with [AI-Thermometer](https://github.com/tomek-l/ai-thermometer) project using Nvidia Jeton Nano.

The project is using Pi camera v2 for video capturing.
Here's the command of showing video streams using Pi camera v2.

```sh
gst-launch-1.0 nvarguscamerasrc sensor_mode=0 ! 'video/x-raw(memory:NVMM),width=3264, height=2464, framerate=21/1, format=NV12' ! nvvidconv flip-method=2 ! 'video/x-raw,width=960, height=720' ! nvvidconv ! nvegltransform ! nveglglessink -e

```

I want to use the normal USB webcam (such as Logitech c930) instead of Pi camera v2.
To do so, I need to stream the USB webcam data using GStreamer in the same way as above pipeline commands.

I installed `v4l-utils` on Ubuntu of Jetson Nano. And tried like this,

```sh
gst-launch-1.0 v4l2src device="/dev/video0" ! 'video/x-raw(memory:NVMM),width= ...

```

, but it gave a warning and didn't work.

How can I show video streams from webcam?

Answer: 
There should not quotes around the device parameter i.e. `device=/dev/video0`. If the error persists, then its probably something else.
```none
gst-launch-1.0 v4l2src device="/dev/video0" ! \
  "video/x-raw, width=640, height=480, format=(string)YUY2" ! \
  xvimagesink -e

```