Linux

I have a c920 and it's complete poop. Random hiccups and stutter and the auto focus fails.

My c920 now glitches out and refuses to stream video after about 10 minutes of use (mic still works tho). After some unknown long period of time, it resets and works for another 10 minutes

C920 is good enough for meetings. I solved the focus problem using the traditional Linux method of writing of udev rule which launches a timer when it's plugged in, which periodically launches a systemd service, which runs a bash script to make sure it self-corrects at least every 5 minutes.

❯ cat /etc/udev/rules.d/90-video4linux-webcam-config.rules
KERNEL=="video[0-9]*", SUBSYSTEM=="video4linux", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="0892", TAG+="systemd", RUN{program}="/bin/systemctl start video4linux-webcam-config@$env{MINOR}.timer" ENV{SYSTEMD_WANTS}="video4linux-webcam-config@$env{MINOR}.timer"

❯ cat /etc/systemd/system/[email protected]
# This file is managed by ansible-video4linux-webcam-config
[Unit]
Description=Periodically restart webcam config service

[Timer]
# Unit= defaults to service matching .timer name
OnActiveSec=30

[Install]
WantedBy=timers.target

❯ cat /etc/systemd/system/[email protected]
[Unit]
Description=Set webcam configs

[Service]
Type=oneshot
ExecStart=/bin/bash -c "/usr/local/bin/video4linux-webcam-config.sh %I"

[Install]
WantedBy=multi-user.target

❯ cat /usr/local/bin/video4linux-webcam-config.sh
#!/bin/bash

if [[ $# -ne 1 ]]; then
  echo "Expected minor device number as sole argument" 1>&2
  exit 1
fi

   v4l2-ctl -d $1 --set-ctrl focus_automatic_continuous=0
  v4l2-ctl -d $1 --set-ctrl focus_absolute=0