This page aims at giving a simple introduction to holding a talk over
the net, with the Speaker interacting only with Big Blue Button and
recording/streaming handled by a separate person somewhere else — this
should allow for talks given by speakers who have little to no
experience with audio/video streaming, as that is handled by the Stream
Angel. Additionally, for live Q&A, a Signal Angel may also join the
conference.
For now, this setup assumes that there is just one Speaker, but it
should be relatively easy to expand it to several Speakers (e.g. for
panel discussions) if needed — although the Stream Angel may end up with
an inordinate amount of browser windows (and need a lot of downlink)
…
This setup is specifically for situations in which you cannot use big
blue button itself for the live stream (e.g. because there are too many
people in the audience — most big blue button instances appear to break
down once the number of participants gets unreasonably high) and/or
recording — if you only want a recording of a talk, the inbuilt
recording feature of big blue button is pretty easy to use and produces
really cool output, but less portable than a normal video. You can of
course also use both, and have one as a backup.
This article was written partly for the Ringvorlesung Umwelt at
the TUM, but is intended to be as general as possible and adaptable to
other situations as well.
Context
Requirements
The following software is assumed to exist somewhere in the context
of this page:
- a computer on the Speaker's side, with webcam and microphone as well
as enough uplink capacity to stream basic video
- a big blue button instance
- if unavailable, a jitsi meet instance could be used as a fallback,
though it's less pretty
- a computer on the Stream Angel's side which is fast enough for live
encoding and has sufficient downlink for big blue button
- Optionally (but recommended): a microphone on the Stream Angel's
side. This will not be recorded, and can thus be useful to give the
Speaker hints and (limited) technical support if anything goes wrong
without the audience noticing
- for livestreams, enough uplink on the Stream Angel's side for
HD-video streaming (the font on the slides should be readable, after
all)
- a hard drive and/or streaming server somewhere as target for the
processed video stream
Roles
This page assumes chaos-event-style roles and names them as such:
- the Speaker is the person giving the talk
- the Stream Angel is the person who does the recording and/or
livestreaming
- the Signal Angel is the person reading the chats and collecting
questions, which they can then read to the Speaker
Of course, depending on your situation and requirements, you may also
create additional roles (e.g. a Herald to announce the Speaker, more
Signal Angels, etc.). Be sure to tell the Stream Angel about them if
they need to speak in the stream or even have their video there.
It may prove useful to have all Angels in a separate conference (e.g.
on a mumble server), so that they can all talk to each other during the
event without being heard in the livestream.
Speaker's side
Requirements
- webcam and microphone
- slides as pdf
- a nice, non-distracting background for your talk
Before the Talk
- if your computer/laptop has a webcam and microphone, great! If not,
you will need external ones
- follow good practice for audio recordings to avoid echos etc.
- The Stream Angel should have sent you a link to a big blue button
instance. Open it, select "with microphone"
- your browser should ask you to allow big blue button to access your
webcam and microphone; click on "allow"
- do the echo test (if you cannot hear yourself, try choosing another
microphone — if this does not work either, either know what's gone wrong
or ask the Stream Angel or someone else who is likely to have some
idea)
- if you aren't already, make yourself the presenter (by clicking on
the plus in the bottom left corner of the screen)
- upload your presentation as pdf:
- click on the plus in the bottom left corner of the screen, and
choose "upload presentation"
- click on "add file" and select your slides as pdf from your
drive
- press the blue "upload" button at the top right
- wait for big blue button to upload and process your slides (you
cannot really do anything in the meantime)
- once processed you will be returned to the main view, where you
should now see your presentation
- familiarise yourself with the controls before starting the talk:
- you can go through the slides with the buttons at the bottom, or
with the arrow keys on your keyboard
- you can zoom in on the slides with your mousewheel — be aware that
this will also zoom into the slides for your audience, so don't overdo
it
- on the right side you have a toolbox where you can select a brush,
colour, and brush size, in case you want to add notes to your
presentation or highlight a particular section for your audience. You
also have an undo-button to go back one step, and a clear-button to
clear the entire page
- If you want to show your audience a video, demonstrate some program
on your computer or cannot convert your slides to a pdf, you can also
choose to share you desktop instead (click the corresponding button in
the icon tray on the bottom of the screen). You can also use this
feature to show the Stream Angel your desktop in case seomthing's gone
wrong and you're out of ideas
During & After
Everything works as intended? Great! Then start your talk once the
Stream Angel gives you a go (don't start earlier, as the
recording/livestream may not yet have started!)
If there is a Q&A session following directly to your talk, you
will probably receive the questions either through the chat on the left
side of the screen, or a Signal Angel will read them to you directly
through Big Blue Button.
Once you are done with your talk, lean back; the Stream Angel will do
the rest of the work. Once they confirm that the stream has ended,
simply close the tab in your browser.
Stream Angel
Requirements
- a computer fast enough to handle live encoding
- it has have either a very large screen which can display at least
two full-hd-windows next to each other, or a window manager that does
not suspend rendering windows if they aren't visible (gnome on x.org
seems to work)
- if there is a stream, a stream key
- if there is a recording, someplace to store it
- a microphone to give tech support and hints to the Speaker (these
will not be audible in the stream/recording)
Before the Talk
Configuring Big Blue Button:
- start a conference in big blue button, send the invite link to the
Speaker (and, if there is one, the Signal Angel)
- check that your own microphone works
- maximise the slides in big blue button
- start another window of your browser and join the conference a
second time, and maximise the Speaker's video
- (optionally) open yet another browser window and join the conference
a third time if you want to have the normal bbb interface as well
- know what the Speaker is supposed to do; possibly you may have to
give them some tech support if they've not done something like this
before
- ONCE EVERYTHING ELSE WORKS (including the obs setup!): use your
browser's development console to remove the "minimize"-buttons of big
blue button — avoid doing this too early, as otherwise you may no longer
be able to change anything
Configuring obs:
- check recording directory and/or stream target and key
- check target resolution and encoder settings
- add sources in obs:
- a window capture source recording your first browser window for the
slides
- a window capture source recording the second browser window for the
Speaker's video
- an audio capture source capturing your desktop audio, if it is not
already recorded by default (pulseaudio source works well for this)
- optionally: remove gray video borders by cropping the video
- optionally: add image/video sources as decoration
- add scenes, transitions, and effects to your liking
- add a "pause" scene which can be displayed before and after the
stream
- if there's a Q&A, add an extra overlay for it displaying the
link to any feedback chats
- check that your own microphone is not being recorded
- (here remove the bbb minimize-buttons in your browser)
- start recording and stream
- everything works as intended? Great, give the Speaker a go! (do a
dramatic countdown if you like)
During the Talk
- check that everything looks fine
- transition between your scenes as you like/think sensible
- if obs crashes, restart it. possibly alert the Speaker that they
should repeat the last couple sentences
- check that no frames are dropped. if too many are, close other
programs. if they still drop … well, there's not much you can do except
upgrading your hardware or streaming at lower quality/resolution (if you
only do a recording and no livestream, you can set the encoder to
produce laughably large video files at low compression, which you can
re-encode afterwards — takes ages, but should look a lot better)
After the Talk
- Switch to the pause scene, or play credits if you have any
- shut down stream and recording
- tell the Speaker they're now offline
- (if livestream): cut off extra stuff from the restream
- (if recording): open up a video editing software to correct any
errors
Signal Angel (optional)
Before the Talk
- Check that any chatrooms/irc channels/matrix rooms/pads/whatever
your use to collect questions from your audience work
- Check that you have moderator status in all of them
- Check that someone posted a link to them somewhere where your
viewers will find it (if no one did, call the Stream Angel to put them
on display via obs)
- join the big blue button conference via link, do the echo test, then
mute your audio
During the Talk
- moderate the chats
- announce that you're there, and that people may ask questions in the
chat
- if anything goes wrong, apologise for the inconvenience
- don't press the Stream Angel too much, they're probably very busy
right now
- collect those
- during the Q&A, unmute your microphone and read the questions to
the Speaker
After the Talk
- leave a friendly message in the chats, thank everyone for their
questions, possibly alert viewers to the date of the next talk (if there
is one)
- leave the big blue button conference (simply close the browser
tab)