[PLUG-AV] Notes about streaming events on BigBlueButton

[James Henstridge]

As we've streamed and recorded two events via BigBlueButton, I thought
I'd jot down some notes to help with future events.

First a quick comparison of the setups at the two events:

July:
* Everything captured from one laptop.
* Slides were PDF uploaded into BBB, with some screenshare for demo
* Video from one of PLUG's cameras, captured via an ezCap HDMI capture device.
* Sound via a USB headset I was wearing

September:
* Two laptops used: slides from presenter's laptop, video/audio from a second.
* Slides were done entirely via screenshare
* Same camera + HDMI capture setup for video
* Sound from the camera's mic, also via HDMI capture.

We lost some video/screenshare footage from the September event,
likely due to some network issues.  Interestingly, it looks like we're
missing some video footage from the recording that it appears BBB
showed to live viewers (at least based on part of the slides video as
screenshare was turned back on.

## Camera Setup

Our existing Canon DV cameras have worked fine at the last two events.
The main thing to remember is to configure them to produce a clean
feed on their HDMI output.  If you see an overlay on the HDMI output,
go to Settings -> Display -> Television and choose "off".  This turns
off the overlay rather than the output.  The overlays will still be
visible on the camera's own preview screen.

If possible, the camera should be positioned so it can frame the
speaker without the projector screen in the background.  The screen is
very bright, and will leave the speaker underexposed.

## HDMI Capture

I'm happy to continue loaning my capture card to PLUG for events.  The
only real problem we've had with it is that BBB seems to always select
the card's 640x480 frame size, which squashes the widescreen capture
down to 4:3.  I can stretch it back out for the final rendered video
though.

If we can get one of the hdmi2usb.tv boards working, it would be an
alternative too.

## Sound

The camera's mic gave reasonable audio but also captured a fair bit of
the room's background noise.  The headset I used in July was better at
capturing just my voice, but it felt weird wearing headphones while
giving a talk.

It would be good to see if we could get PLUG's wireless mic working
for a future event: either through the mixing board (that might be
malfunctioning?) or hooked up directly to a laptop's 3.5mm jack.

## Slides

Using BBB's slides feature seems the most reliable, but is
inconvenient if the speaker wants to frequently switch away from
slides to perform demos as enabling screenshare incurs a delay.

Using screenshare to show a LibreOffice presentation results in
Firefox's privacy indicator displaying over the slides though.  We
should check out how Chromium handles this case.

If the speaker has no demos, or only one section of demos, it is
probably best to steer them towards the PDF slides option.

## Making the video

Make sure to hit record within BBB before the presentation and stop at
the end.  After BBB has finished processing the recording, get Nick to
make it public.  The final video can be produced using bbb-render:

https://github.com/plugorgau/bbb-render

Follow the instructions in the README.  When running make-xges.py,
include "--backdrop=plug/backdrop.png --stretch-webcam" in the options
to add PLUG branding and correct the webcam aspect ratio.

I rendered to a 1080p MP4 using the ges-launch-1.0 invocation listed
in the README, which YouTube seems happy with.  We're also saving a
copy of the MP4 for our own archives.

James.