Configure a Webcam

webcam is the general camera model. If the camera drivers are among those in this mediadevices repository, the camera will work with the webcam model.

• Config Builder
• JSON Template
• JSON Example

Navigate to the CONFIGURE tab of your machine’s page in the Viam app. Click the + icon next to your machine part in the left-hand menu and select Component. Select the camera type, then select the webcam model. Enter a name or use the suggested name for your camera and click Create.

Edit and fill in the attributes as applicable. If you click on Show more, then the video_path field while your machine is live, a dropdown autopopulates with identified camera paths.

{
  "name": "<your-camera-name>",
  "model": "webcam",
  "type": "camera",
  "namespace": "rdk",
  "attributes": {
    "intrinsic_parameters": {
      "width_px": <int>,
      "height_px": <int>,
      "fx": <float>,
      "fy": <float>,
      "ppx": <float>,
      "ppy": <float>
    },
    "distortion_parameters": {
      "rk1": <float>,
      "rk2": <float>,
      "rk3": <float>,
      "tp1": <float>,
      "tp2": <float>
    },
    "debug": <boolean>,
    "format": <string>,
    "video_path": "<your-video-path>",
    "width_px": <int>,
    "height_px": <int>,
    "frame_rate": <float>
  }
}

{
  "name": "my_cam",
  "model": "webcam",
  "type": "camera",
  "namespace": "rdk",
  "attributes": {
    "video_path": "video0"
  }
}

The following attributes are available for webcam cameras:

Using video_path

To list available video_paths use the following command:

ls /dev/v4l/by-id/

v4l2-ctl --list-devices

system_profiler SPCameraDataType

Using format

Viam supports the following pixel formats:

• I420
• I444
• MJPEG / MJPG
• NV12
• NV21
• RGBA
• UYVY / Y422
• YUY2 / YUYV / V422
• Z16

If your machine is connected to the Viam app, the available pixel formats supported by your camera automatically appear in the Format dropdown menu, which is visible when you click the Show more button.

On Linux, you can also manually determine which pixel formats your camera supports by running the following command on the machine your camera is connected to. Replace /dev/video0 with the video path you determined for your video device above, if different:

v4l2-ctl --list-formats-ext --device /dev/video0

View the camera stream

Once your camera is configured and connected, go to the CONTROL tab, and click on the camera’s dropdown menu. Then toggle the camera or the Point Cloud Data view to ON. If everything is configured correctly, you will see the live video feed from your camera. You can change the refresh frequency as needed to change bandwidth.

Troubleshooting

No visible live video feed

If you’re working on a Linux machine, ssh into it, then restart viam-server by running:

sudo systemctl restart viam-server

If this doesn’t work, you can reboot your machine by running:

sudo reboot

Images are dim on start up

If you are capturing camera data, it can happen that the camera captures and syncs miscolored or dark images upon start up.

CSI Camera not working on a Raspberry Pi

If you are using a CSI camera v1.3 or v2.0 on a Raspberry Pi, you need to enable legacy mode. If you are using a CSI camera v3.0, you need to use the viam:camera:csi module instead.

High CPU usage

Each camera stream you add uses CPU on the device it is connected to and there is therefore a practical limit to the numbeof camera streams your device can simultaneously support. You can limit the CPU usage by reducing the image resolution.

Timeout errors on a Raspberry Pi

If you are getting “timeout” errors from GRPC when adding a webcam model on a Raspberry Pi, make sure the webcam port is enabled on the Pi (common if you are using a fresh Pi right out of the box).

To enable the webcam port on a Raspberry Pi, run the following command:

sudo raspi-config

Then, select: Interface Options -> Camera -> Enable Camera.

Restart the Pi to complete the configuration.

Next steps

Calibrate a Camera

Calibrate a camera and extract the intrinsic and distortion parameters.

transform

Instructions for transforming a camera.

Computer Vision

The vision service enables your machine to use its on-board cameras to intelligently see and interpret the world around it.