Automated lecture capture and publishing – ALCP
What is ALCP?
ALCP is a model and an implementation of an automated system for lecture
capture and publishing.
This system provides fully automated support for recording of lectures
based on a schedule that is periodically retrieved from a web address. Fully automated means that there is absolutely no intervention required in
order to have the lecture captured and published. Not even to click Start
or Stop.
What does it do exactly?
The system
consists of one central streaming server and any number of independent
computers called capture agents.
A capture agent is a computer located in a room where capturing is
taking place. It is connected to a camera (to capture video of the lecturer)
and the output of the projector (to capture his presentation/smartboard
drawings). Using ASOP scripts, the capture agent is configured to:
·
Turn on automatically
every morning
·
Check the online
schedule for the next lecture today
·
Wait for the lecture, turn on the camera using an Arduino-controlled relay, capture the lecture and generate lecture livestream
o Repeat this until
the evening
·
In the evening, re-encode
lecture captures (each consisting of two .mp4 media files – dekstop and the lecturer) to target quality and upload them to streaming server
·
Shut down until next
morning
The central server on the other hand checks every morning
if any new recordings have been uploaded to it, then puts them into
corresponding folders and publishes access links. Published media files can be
consumed separately in a web browser (lecturer and desktop), both synchronized
in LeCTo Player, or can be downloaded.
How does it work?
ASOP is
Linux-based. The central server is a
plain Linux server running Apache with HTTP pseudostream module, no graphical
user interface is needed.
A capture agent uses
only standard Linux commands (at, rtcwake) and:
·
ffmpeg, a free and “… complete,
cross-platform solution to record, convert and stream audio and video”
·
VLC, “a free and
open source cross-platform multimedia player”, here used for livestreaming.
Where can I get ALCP? What hardware/software
do I need?
Our current hardware setup is:
·
Sony HDRX900E camcoder with HDMI output,
currently mounted on the ceiling in the capture room and connected to the
capture agent using HDMI cable
·
Blackmagic Intensity Pro HDMI capture card
to get HDMI input to the capture agent
·
Epiphan VGA2USB frame grabber to get VGA output from
the projector to the capture agent
·
Samson UB1 USB microphone omnidirectional microphone for the
lecturers desk
·
Dell PowerEdge T420 capture agent computer
·
Arudino Uno and a simple 5V 230V relay to turn the
camera on/off
Software setup:
·
Ubuntu 16.04 LTS (previously 12.04 LTS). Any other Linux should also do.
·
Capture agent scripts and instructions available on request.