ArchLinux ElGato FaceCam - Chrome V4L2Loopback

README.md

ArchLinux ElGato FaceCam - Chrome V4L2Loopback

IMPORTANT

This is not required any more, you need upgrade your firmware to the version +4.09 using ElGato Cammera Hub

https://help.elgato.com/hc/en-us/articles/4406041241997-Elgato-Facecam-Firmware-Update

Changes in firmware 4.09

• Added MJPEG as a fallback video format. MJPEG requires less USB bandwidth and improves compatibility with programs that cannot handle uncompressed video.

Loopback Config

I'm creating 3 Loopback devices, if you only need do this for the Facecam you can define only one like this:

options v4l2loopback video_nr=11 card_label="ElGato FaceCam"

WebCam Path

I'm using my serial as a path to not conflict with my another input devices /dev/v4l/by-id/usb-Elgato_Elgato_Facecam_FW42K1A07115-video-index0 on the facecam-init.sh.

You can check what is your correct path with this command:

ls /dev/v4l/by-id/

WebCam Config

On my facecam-init.sh, I set some parameters that make sense for my enviroment, this maybe cannot fit for you, so you can remove this line.

v4l2-ctl -d /dev/v4l/by-id/usb-Elgato_Elgato_Facecam_FW42K1A07115-video-index0 --set-ctrl="brightness=180,contrast=3,saturation=35,white_balance_temperature_auto=1,power_line_frequency=2,sharpness=1,exposure_auto=2,zoom_absolute=5"

or adjust the parameters that you want.

Run

You need start the script to create the pipe from the FaceCam Device to the LoopBack Virtual Device

• Add execution permissions:

chmod +x facecam-init.sh

• Run

./facecam-init.sh

facecam-init.sh

#!/bin/bash

v4l2-ctl -d /dev/v4l/by-id/usb-Elgato_Elgato_Facecam_FW42K1A07115-video-index0 --set-ctrl="brightness=180,contrast=3,saturation=35,white_balance_temperature_auto=1,power_line_frequency=2,sharpness=1,exposure_auto=2,zoom_absolute=5"

ffmpeg -f v4l2 -input_format uyvy422 -framerate 60 -video_size 1920x1080 -i /dev/v4l/by-id/usb-Elgato_Elgato_Facecam_FW42K1A07115-video-index0 -pix_fmt yuyv422 -f v4l2 /dev/video11

module.conf

# /etc/modules-load.d/v4l2loopback.conf
v4l2loopback

options.conf

# /etc/modprobe.d/v4l2loopback.conf
options v4l2loopback video_nr=10,11,12 card_label="OBS Virtual","ElGato FaceCam","V4L2Loopback" exclusive_caps=1,1,1

Is this working consistently for you folks? I'm using obs-studio and its virtual camera, but while it works for a while (and needs an occassional usbreset between sessions), it still hangs/freezes mid-stream. I can't get it to work for an extended period of time. This is regardless if using MJPEG, or the frame rate, etc.

I been using the camera with the new firmware consistently (Without this script) , however as @kouak mention sometimes the camera don't show up on boot (a quick disconnect and connect fix the issue). I think that happen because the cam have in the firmware some logic to detect if is connected to usb2 and show the device as something like "Connect this in a USB 3.0 port".

I'll check out the v4l2loopback method then. I'm already on the latest firmware but maybe this is some interaction with obs-studio.