windows_webcam_monitor

Abstract

This is a little windows service written in python to determine if any process uses a webcam in Windows 10 and publish the results via mqtt. I implemented this because I wanted to automate the lighting in my homeoffice during video calls.

The algorithm is based on registry keys in Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\CapabilityAccessManager\ConsentStore\webcam\NonPackaged, where each process that has a handle on a webcam is registered. If a process currently has a handle, its LastUsedTimeStop key equals 0.

I do not guarantee for this to work in the future but in my environment it works pretty well. As I did not find anything to do this I thought I'd share.

Features

No process using a webcam

Webcam used by a process

Dependencies

• Windows 10
• python >= 3.5
• paho-mqtt

How to install

1. Install python on your windows machine
2. pip install -r requirements.txt
3. create your config.ini from config.ini.example
4. python service.py

As a service

To run the script as windows service and start it automatically with windows, you could use nssm.

1. Install nssm
2. Run nssm install WindowsWebcamMonitor as administrator

Example: Integration in Home Assistant

Put this in your configuration.yaml

sensor:
  - platform: mqtt
      name: Webcam
      state_topic: "windows_webcam_monitor/used_by" # this must match with "path" in config.ini
      icon: mdi:webcam