Linux Virtual Delivery Agent

HDX webcam video compression

Overview

Users of video conferencing applications running in Linux VDA sessions can now utilize their webcams with HDX webcam video compression. This feature is enabled by default. We recommend you always use HDX webcam video compression if possible.

HDX webcam video compression is also called Optimized webcam mode. This type of webcam video compression sends the H.264 video directly to the video conferencing application running in the virtual session. HDX webcam video compression uses the multimedia framework technology that is part of the client operating system to intercept video from capture devices, transcode, and compress it. Manufacturers of capture devices supply the drivers that plug into the OS kernel streaming architecture.

The client handles communication with the webcam. The client then sends the video only to the server that can display it properly. The server doesn’t deal directly with the webcam, but its integration gives you the same experience in your desktop. Workspace app compresses the video to save bandwidth and provide better resiliency on WAN scenarios.

Webcam compression

Note:

  • This feature supports only H.264 videos from your Citrix Workspace app client.
  • The supported webcam resolution ranges between 48x32 and 1920x1080.
  • Do not choose Generic USB devices from your Citrix Workspace app toolbar when you are using a webcam. Otherwise, unexpected issues might occur.
    Generic USB devices

Supported Linux distributions

  • RHEL 8.4/CentOS 8 (2105)
  • RHEL 8.3/CentOS 8.3
  • RHEL 7.9/CentOS 7.9
  • Ubuntu 20.04
  • Ubuntu 18.04
  • Ubuntu 16.04
  • Debian 10

Fully tested webcams

Different webcams offer different frame rates and have different levels of brightness and contrast. Citrix uses the following webcams for initial feature validation:

  • Logitech HD Webcam C270
  • Logitech Webcam C930e
  • Microsoft-LiftCam-HD3000

Configuration

This feature is enabled by default. To use it, complete the following verification and configuration:

Tip:

Citrix Workspace app users can override the default setting by choosing the Desktop Viewer Microphones and webcams setting, Do not connect. Do not connect

  1. After your VDA installation completes, verify that your VDA can register with the Delivery Controller and the published Linux desktop sessions can be launched successfully using Windows credentials.
  2. Run the sudo /opt/Citrix/VDA/sbin/ctxwcamcfg.sh command to complete your webcam configurations.

    Before running the ctxwcamcfg.sh script, ensure that your VDA has access to the Internet. If your VDA is deployed on Debian 10, ensure that it is running on the latest kernel version. Otherwise, run the following commands to update to the latest kernel version:

    sudo apt-get update
    sudo apt-get dist-upgrade
    sudo reboot
    

    The ctxwcamcfg.sh script helps to:

    1. Install the FFmpeg, kernel-devel, and Dynamic Kernel Module Support (DKMS) programs on your VDA.
      • FFmpeg is used for video decoding.
      • kernel-devel is used to build a virtual webcam kernel module of the corresponding version.
      • DKMS is used to dynamically manage the virtual webcam kernel module.

      Note:

      When installing the preceding programs on RHEL and CentOS, the ctxwcamcfg.sh script installs and enables the following repositories on your VDA:

      • Extra Packages for Enterprise Linux (EPEL)
      • RPM Fusion
    2. Download the v4l2loopback open source code from https://github.com/umlaeute/v4l2loopback and use DKMS to manage v4l2loopback.
      v4l2loopback is a kernel module that allows you to create V4L2 loopback devices.

    3. Run the sudo service ctxwcamsd restart command. The Linux VDA’s webcam service - ctxwcamsd - restarts and loads the v4l2loopback kernel module for the HDX webcam video compression feature.
HDX webcam video compression