Whiteboard Screencap

Chalk-and-talk online: whiteboard screencasting (on Linux)

Well, all my logic lectures moved online as of last week. It’s been a bit of a scramble, as I’m sure it’s been for you as well. I needed to rapidly produce videos of lectures (on logic in my case) I can give with students to watch. I thought I’d quickly share what I’m doing in case you’re in a similar situation.

My laptop runs Linux (Ubuntu 19.10 to be specific). So there are few options. If you’re on a Mac or Windows machine, there’s lots and you probably don’t need any help. Maybe your University even has a preferred solution for screencasting that integrates with your LMS.

For screencast recording on Linux I find Kazam works fine. It’s super-simple, all it does is record the microphone (or computer speaker output) together with whatever happens on your screen (or in a window). So if you want to show your students how to work Overleaf or Carnap or whatever, or if you want to show them a beamer presentation and talk over it, that’s all you need. (Well, you might want to invest in a decent microphone.)

But what if your lecture is chalk-and-talk? You need a way to let yourself “write on the board” while you talk through your proof or whatever. For that you need a handwriting/sketching app and a way to write comfortably (touchscreen/tablet and stylus). I did get a stylus and an Android tablet and tried out a few handwriting apps, but I couldn’t get the palm rejection to work on any of them. (If you rest your palm on the screen, the tablet won’t recognize what your stylus is doing, so you need an app or a stylus that can isolate the stylus from your hand. I’m told iPads are better for that and/or there are active styluses that have palm rejection built in. Not going to buy an iPad just to try that out though.)

I also have a Wacom Intuos writing tablet I got last week in panicked anticipation ($70 US/CAD 90). It works with Linux (plug-and-play USB), just takes a little getting used to. For a handwriting app, I discovered StylusLabs Write. It works really nice. I just fire it up, hit record on Kazam, start writing. It can easily add a new page/whiteboard area, you can scroll back to a previous one easily, and in the end you can save the whiteboard as a PDF. Here’s an example of me talking through the truth lemma in the completeness proof. {Update: See comment below for a vote for xournal++.} {Update 2: OpenBoard now runs on Ubuntu 20.04 — full-feature whiteboard with PDF import functionality and built-in screencast support!}

What is your solution? I made a Google spreadsheet where you can record your solution; maybe it’ll help other instructors who are struggling right now to adapt in the great COVID-19 rush online.

I would prefer to use my ReMarkable for all of this: it has a desktop app for Mac & Windows that shows what you’re drawing on it. So if you have one, try that out! I was hoping to make it work in Linux using srvfb, but have to wait until ReMarkable fixes a bug that turned off ssh access to the tablet. Will let you know what I find out.

{UPDATE (02/2021): I now use tableaunoir ! It is online, supports sharing (your students can also draw on the blackboard) and also LaTeX code. It has chalkboard sound effects. Special feature: You can also turn parts of the board into “magnets” which you can then move around. As part of a diagram, edges between magnets move with them if you move the magnets.}

5 thoughts on “Chalk-and-talk online: whiteboard screencasting (on Linux)

  1. On the bright side, this could mean that you might decide to upload your lectures so that we could also use them. Right?

    1. In principle yes. But our semester only has 3 weeks left so there won’t be a lot.

  2. Great idea, Richard. I’ve been using OneNote on my Surface tablet (I know, I know M$…). I’ve been recording my screen and audio using the Microsoft Game Bar, which is built in to Windows 10 (win + g to open it) and uploading the results to YouTube. It seems to be working pretty well so far.

  3. A wonderful option for the whiteboard is to use xournalpp (also known as xournal++) https://github.com/xournalpp/xournalpp

    In my opinion this option it is even better tha StylusLabs Write because:
    – there is ongoing development
    – it even has as LaTex plugin for displaying LaTeX code as images (unfortunately it misses, as far as I have checked, the optionn of displaying LaTeX code as “unicode text”).
    – you can also annotate during the lecture your own pdf slides.

  4. Awesome article ,and interesting tools . My school bought me a XP-PEN Star G960S https://www.xp-pen.com/product/574.html digital writing drawing pad and I use it. I like it a lot. I use it at home for videos , and for online teaching (with OneNote , whiteboard app…keeping it simple).

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