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.

Navigate to the Config tab of your machine’s page in the Viam app. Click on the Components subtab and click Create component. Select the camera type, then select the webcam model. Enter a name for your camera and click Create.

Configuration of a webcam camera in the Viam app config builder.

Edit and fill in the attributes as applicable. If you click on 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:

NameTypeInclusionDescription
video_pathstringOptionalThe ID of or the path to the webcam. If you don’t provide a video_path, it defaults to the first valid video path it finds. Using the ID of a webcam is more consistent than the path. See Using video_path.
formatstringOptionalThe camera image format, used with video_path to find the camera. See Using format.
width_pxintOptionalThe camera image width in pixels, used with video_path to find a camera with this resolution.
Default: Closest possible value to 480
height_pxintOptionalThe camera image height in pixels, used with video_path to find a camera with this resolution.
Default: Closest possible value to 640
frame_ratefloatOptionalThe camera capture frequency as frames per second, used with video_path to find a camera with this throughput.
Default: Closest possible value to 30.0
intrinsic_parametersobjectOptionalThe intrinsic parameters of the camera used to do 2D <-> 3D projections:
  • width_px: The expected width of the aligned image in pixels.
  • height_px: The expected height of the aligned image in pixels.
  • fx: The image center x point.
  • fy: The image center y point.
  • ppx: The image focal x.
  • ppy: The image focal y.
distortion_parametersobjectOptionalModified Brown-Conrady parameters used to correct for distortions caused by the shape of the camera lens:
  • rk1: The radial distortion x.
  • rk2: The radial distortion y.
  • rk3: The radial distortion z.
  • tp1: The tangential distortion x.
  • tp2: The tangential distortion y.
debugbooleanOptionalEnables the debug outputs from the camera if true.
Default: false

Using video_path

To list available video_paths use the following command:

ls /dev/v4l/by-id/

To find the paths of all connected video devices, run the following command:

v4l2-ctl --list-devices

The id listed by ls /dev/v4l/by-id/ is a more consistent way to refer to the webcam.

See Camera troubleshooting for Linux-specific camera troubleshooting steps.

system_profiler SPCameraDataType

The Unique ID displayed for each camera is the video_path.

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.

Example Camera view inside Viam app

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



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