669. Checking how many students attended a zoom lecture, afterwards

 This is an easy one, but you need to know that 1) the option is there and 2) where to look.

Go to the web-interface to zoom at your institution, and click on log in:

Now that you're in, go to to Reports:

Then go to Usage:

Now, search for the time period that you're interested in:

And click on the number of attendees. Note that if someone gets disconnected, and then reconnect, they're counted twice, so this is not the value you want to use:

Instead, make sure to click "Show unique users" to see how many students actually attended. You can also export it as a csv file which is probably a good idea since you'll need to count by hand otherwise:

That's it.

667. XP PEN/virtual whiteboard during a lecture -- mirroring an application window on linux

The situation:

We're allowed to teach on campus at the moment, but we're also strongly encouraged to adopt a hybrid model where we stream everything via zoom so that students don't show up if they have flu/cold-like symptoms.

We've spent the past few years killing off ppt and transitioning to whiteboard/chalk-and-talk. The students love it -- the pace is better, and the lectures become more interactive since we can adjust our teaching to the students' learning. Good stuff. But horrible for streaming -- you can't just point a webcam at a whiteboard and expect a good outcome (although if need be, it can be done -- just use a good camera and write large with a dark pen).

I have an XP Pen Artist 13.3 Pro (https://www.parkablogs.com/content/review-xp-pen-artist-133-pro-pen-display ) which is fantastic for drawing. A lot of fun, and a potential solution to the whiteboard quandary.

The Problem:

Both the students in the class room and those following the lecture on zoom need to be able to see what you're doing. And since the pen display is a DISPLAY, you need to have your drawing program open on the pen display, and not on the projector (which is also a display).

The Solution:

1. Open your drawing window (xournal, or xournal++ or openboard or krita) on your pen display ... display. 

2. Then run xwininfo (part of x11-utils) and click on your window. You get a window id, e.g. 36000a

Then run x11vnc:
x11vnc -id 36000a

Note the port number -- likely 5900.

The window is now being shared via vnc. 

3. To see it, use e.g. vinagre, click Connect, set the protocol to vnc and the port to 5900 (and you're presumably connecting to localhost). 

Make sure to enable 'scaling', since many old video projectors have a 4:3 resolution ratio, whereas e.g. the xp pen 13.3 has a 16:9 ratio.

Drag this window to the projector.

4. Share the original window via zoom

Note that I've had issues getting the pen display to map correctly when all three display (laptop, xp pen, and projector) are connected. Turning off the laptop screen solved it.

A script:

I've made a script called mirror.sh which starts the x11vnc with the correct id:

winid=`xwininfo |grep "Window id"|gawk '{print $4}'`
x11vnc -id  $winid

666. Zoom -- multiple booking for a course

Problem:

Recurring bookings are easy enough to make in zoom, but what do you do if your lectures are given at different times each day?

Solution: 

make a recurring booking e.g. at 8 am, 2 hours, each day for two weeks. 'When' is not important.

Then go in and edit the booking. You can then change the times for each zoom meeting:

You can also delete meetings e.g. those that fall on weekends:

663. Giving a zoom + on-campus lecture (on linux, win and mac)

Preamble:

The uni admins aren't making it easy for us. 

I can handle doing everything on-campus, giving good, or occasionally very good, lectures using the white board and making it dynamic by actually engaging with the target, the students. I can often get them to share my excitement over the amazing stuff we're discussing (especially MO theory -- it's my favourite topic, and my favourite lecture). 

I can handle doing everything online if necessary, optimising my lectures to work through zoom or, even better, do away with lectures completely and rely on pre-recorded videos that take advantage of the video format, and use them to flip the class. We can then meet up on zoom to discuss the topics.

But what we're being asked to do is to focus on on-campus teaching, while making sure that everything is being streamed live online to avoid students from showing up to class when infectious.

Note that in our lecture halls we don't have computers. We're expected to bring our own, and we use single projectors. We also don't get any help from IT. Nothing is ever recorded here.

This is incredibly primitive and unprofessional compared to how things were done back in Australia.

What I will show here:

A few approaches to making a lecture work OK for both on-campus and online students simultaneously, and easily. The solutions assume that there's no competency, interest or support from IT.

1. The Basic
The easiest approach is to start zoom on your laptop, share a set of slides and stream it. You need to think about audio though, and there are a number of wireless solutions.

We've been told to use bluetooth headsets, but bluetooth has poor audio. Using 2.4 GHz wireless headsets, like my old logitech G930, gives better audio, but then you can't hear the local audience properly. 

My preferred solution is to use a Samson XPD2: 
http://www.samsontech.com/samson/products/wireless-systems/xpd-series/xpd2lav/

It's not a headset -- sound won't come out of it, but you can crank up the sound on your computer (or even use external speakers -- I have a very old HP USB speakers that are just about loud enough for a lecture hall (https://support.hp.com/ca-en/document/c02574017)

You can obviously switch input to webcam/document cam etc., but it's pretty basic.

If you have a document camera you can use this just like a webcam. Or you use e.g. https://gitlab.com/docphees/doccam to manage your document camera, and then use the window as input to zoom through share screen.

2. With a bit of Flair

This is a somewhat technical solution on linux, but I think it's easier on win/mac. What we can do is to set up a virtual webcam. The contents of the virtual webcam will be supplied by obs-studio

We then use obs-studio -- in studio mode no less -- to switch between different types of views.

virtual webcam: If you're on linux you need to install v4l2loopback (either as the dkms in the deb repo, or by a very simple compile), and if you're on linux you need the v4lsink. If you're on win/mac you can simply install the virtual camera plug-in for obs-studio.

On linux you need to create a virtual webcam:
sudo modprobe v4l2loopback video_nr=10 card_label="OBS Video Source" exclusive_caps=1

In obs-studio you then choose Tools/V4L2 Video Output and choose /dev/video10

obs-studio
Once that's up and running, set up at least two scenes in obs-studio, and pick studio mode.

I've set up one scene with a lion and a styracosaurus on a webcam, with the background chromakeyed out* over a molecular simulations video, and another one showing the guardian website, but one could've been the window with your slides, and another could be a document camera.

I've then set up ctrl+shift+alt+5 to switch between them:

You can even have different audio input depending on the scene. Useful if you're using wired microphones and moving between different stations in your lecture hall.

In zoom: now all you need to do is to pick the virtual webcam device as your input in zoom. There is a CPU overhead to using obs-studio, so expect the laptop to keep the fan on throughout the lecture.

*The chromakey background is the blue cover of an Office Depot notebook :)