E-learning/teaching

This page documents the setup of a Linux system for screencasting

On Screen Display

Show Keyboard commands

When showing software it's usefull for the students to see which keyboard shortcuts are pressed. You can use screenkey, an on screen display (OSD) which should be installed like this: (Don't install from repository)

 git clone https://gitlab.com/screenkey/screenkey.git
 cd screenkey
 sudo ./setup.py install

will install the screenkey application. Run with screenkey

Make sure to check "Show modifier sequences only" otherwise everyone can read your password inputs...

Show Mouse Clicks

There is a feature branch in the screenkey git which implements that, hopefully it will be merged into master once you read this.

Stream Canon 5D via USB

   modprobe v4l2loopback
   gphoto2 --stdout --capture-movie | gst-launch-1.0 fdsrc fd=0 ! decodebin name=dec ! queue ! videoconvert ! tee ! v4l2sink device=/dev/video0

Source

Stream from OBS to a virtual camera source

We can't stream directly from OBS into Jitsi, BigBlueBitton, Google Meet, Skype, etc. For this wee need a virtual camera source.

  modprobe v4l2loopback devices=1 video_nr=10 card_label="OBS Cam" exclusive_caps=1

to install follow these steps:

  apt install qtbase5-dev
  git clone --recursive https://github.com/obsproject/obs-studio.git
  git clone https://github.com/CatxFish/obs-v4l2sink.git
  cd obs-v4l2sink
  mkdir build && cd build
  cmake -DLIBOBS_INCLUDE_DIR="../../obs-studio/libobs" -DCMAKE_INSTALL_PREFIX=/usr ..
  make -j4
  make install

Source

Wishlist

https://www.blackmagicdesign.com/products/intensitypro4k