Lecture Capture at Oxford, Revisited
Those with a long memory will recall the work I posted about during September 2009 (see http://steeple.posterous.com/pilot-capture-environment) where I discussed what we were doing within OUCS at Oxford to test various forms of lecture capture, and technologies to support that.
Since that point, quite a bit has changed. With a focus on our largest teaching space (Isis):
- We've gone through a few different recording / capture methods and technologies
- New AV control system fitted
- New Audio mixer and setup
- New projectors and SMART board
New Projectors & SMART board
With the previous Epson projectors coming to the end of their working lives, a new set of three projectors was selected. A review by the ITLP team at OUCS led to the Epson EB-450W short-throw, widescreen models being selected. This allowed us to provide larger images on the wall for the more common 16:9 / 16:10 display formats favoured by modern monitors and laptops. So far we've been very pleased with both the brightness, contrast, clarity, and general operation of these new displays, and being able to hide two of them in the ceiling improves the appearence of the room (and reduces noise - something these projectors are fairly quiet about in the first place).
As an added bonus, these projectors support video display via Ethernet, so in the future it will be possible for us to send video data to them over the network connections. In the meantime, we're sticking with the analogue video cabling we already have kit installed for. The move to a more complete, modern, digital video setup is a long conversation for another time.
The SMARTboard is an upgrade to the previous model that has been in place for the past 5 years, and introduces both multitouch sensing, and a brighter, widescreen format. The surface is now a more solid metalic one, meaning it feels more robust to the touch, and is essentially a result of a change in the sensing methods used by the board (IR Laser, I believe). Combined with a short throw projector, this allows a presenter to use the board without being dazzled on turning towards the audience, and means there is very little shadow being cast whilst in use and thus less obscuring of content, making it easier to write/draw on the correct area.
New Audio Mixer and setup
One problem we faced for a while was that our rack mountable audio mixer had a slight fault (or perhaps deliberate design fault from its initial installation 6 years ago, it's hard to say) in that of the two "zones" for output, one of them did not contain the microphone feeds. The zone that fed the room audio speakers (and had the volume remote controlled via the AMX panel) featured all the microphone inputs and the selected stereo audio from the VGA matrix, but the second zone only outputted the audio from the VGA matrix. As we specifically wanted a set audio level for recording, taking a feed from the room audio wasn't really a good option, so we looked to replace the mixer as funding allowed. One issue with replacing the mixer was it's ability to accept remote control inputs - however, when the AMX control system failed (more below), this became a moot point for a while.
All of our other rooms feature a completely mixed audio stream to the room speakers, and the setup in place here had the audio being selected via the Extron VGA AV matrix, so users were occasionally surprised when they couldn't hear their movie/audio playing when they could see it on screen (a result of the way and order in which inputs and outputs were selected). A quick bit of research and some hasty shopping netted us an Allen and Heath ZED14 desktop mixer, whose key attributes were having enough input channels to support the range of inputs Isis uses, and a USB audio interface (allowing for a digital link to a computer, nominally for recording purposes).
Whilst the room audio is only mono, the two output channels for recording (see below) were both in stereo, and the Mac Mini being used for screen capture was able to use the USB audio connection - though not without a few flaws: the cable would often need to be unplugged and reconnected or the system restarted after a few days, otherwise the audio device "disappeared".
The other drawback that needed resolving was the lack of a remote control for room audio... but more on that later.
New AV Control System
Due to a failure in our 6 year old AMX Control system within the past few months, we were faced with a either a huge repair bill, or to replace the AMX setup with an equivalent for less cost. Our top tip, if you have a control system installed, make sure you get a copy of all the code and SDKs needed to be able to configure the setup yourself at a later date! This is something that has been a perenial problem with the AMX and one of the factors that caused us to select Extron as the replacement solution.
A review of our previous setup led us to rationalise a few elements: the DVD / VHS player was deemed redundant, and could be removed; The auxiallry composite video inputs couldn't be located, so were presumed legacy and irrelvant; this left just one of the ceiling cameras with a feed to the front desk, and thefore the AV matrix that had been supporting these items could also be removed.
This left the Lutron lighting system, Elmo ceiling camera and the Extron VGA 4x4 matrix requiring RS232 control signals, and the three Epson projectors wanting ethernet based control signals.
Our missing component was a means of controlling the room audio levels from outside of the AV cupboard, so a small Extron Audio mixer was also added to the mix (*groan*) allowing us to vary the feed from the ZED14 to the room Amplifier, and which was also controlled via an RS232 connection.
Extron happen to have a (very small!) control box that supports 4 RS232 connections and up to 6 "virtual" ethernet devices, and we combined that with their TLP 350mv 3.5" touchpanel to complete our new setup. One feature we like is that this approach is modular, and that we can upgrade parts of this setup over time, and reuse pieces in other rooms - so a larger touchpanel may be on the shopping list in the future.
The software for configuring their systems is free and fairly straightforward to use, if incredibly tedious. Top tip: Remember that you are not programming these systems, you are configuring! It's akin to the difference between programming a video recorder to do scheduled recordings and writing an application to generate a calendar from multiple sources and then having your computer capture a video stream... One involves logic and code, the former requires a lot of button pressing.
Basic process is to use one application to design the GUI (can draw it all from scratch, or use a provided template), and then another to assign tasklists to each element of the GUI (e.g. turn projector on, set computer input, select matrix input 1, output 3, take video, unmute the audio, dim the lights... etc). To do this from scratch for Isis with a small amount of training beforehand took about 3 days to get to a workable setup (and having done initial testing and changes based on feedback from the teachers). Experience in Extron configuration would have halved this time, and it's ability to deploy the setups to multiple locations means you can easily manage multiple rooms via this setup (something we'll investigate at a later date).
Our setup is now in it's first extended test (i.e. how does it fare over a term's use), and we have a small list of things to tweak for our next period of downtime. So far it handles room lighting controls, audio (variable volume and an all out mute), camera positioning, and video input and output selections. We have hopes that a virtual remote control setup can be enabled via a web interface, but that is for another time (the basics are there and come as standard with the Extron setup).
Changes to recording methods and technologies
In short...
- We've dropped Podcast Producer as service to support our podcasting and lecture capture activities (problems with reliability of capture being among the reasons).
- The Epiphan VGA2USB devices don't support capture in Quicktime X on 10.6 (Snow Leopard) ^1.
- Trying to use free alternatives to Quicktime in order to do screencapture has resulted in an 80% success ratio and requires a fair degree of technical skill to get into the systems, and set the recordings going - so not one touch and user-friendly. We also didn't find a paid-for application that suggested it would do any better (or that didn't rely on Quicktime).
- The Elmo ceiling cameras^2 installed in the room are not suited to the low lighting levels typically used for presentations, and their 640x480 images aren't exactly detailed or sharp enough for our uses. Also, contrast problems caused by having a flat room and presenters moving in front of display areas, means they struggle to adjust for bright backgrounds and darker surroundings. So we've stopped trying to capture this input.
- We have decided that for occasions when a person or room activity needs to be captured on video, this is best done using a portable video camera. To aide that, we've extended a stereo audio output feed to the back of the room that can be plugged into the camera (or into a digital audio recorder for those occasions when we want a backup to the AV kit up front).
- With a focus on screen and audio capture, we are trialling an Epiphan VGARecorder Lite unit...
Things we like about the VGARecorder include it being an all in one device, small (and thus easy to fit into small cabinet spaces), firmware based with a web interface, supports streaming, can capture over a day's worth of video to its internal (flash) memory and can automatically upload recordings^3 to a remote storage system.
Things we don't like so far are the cost (a mac mini + VGA2USB + composite video capture card is cheaper, let alone a Matterhorn style capture box), that the web interface is rather clunky, slow and confusing (settings one page can have unanticipated results elsewhere, and you're almost forever hunting for the right section to change something related to another aspect), it's slow to reboot and start up (several minutes - rather odd for a flash based system I think), and that it doesn't appear to adapt to different resolutions in terms of adjusting the output recording size (this is still being investigated, but it's a one output size has to fit all approach apparentely).
However, that all said, the device has only been in place for the past week, so we're going to do a more thorough test of it during the coming term. Given we are hosting the Matterhorn Unconference in a couple of weeks, and the Galicaster setup will be on demo too, it will be interesting to see how it compares and fares.
As always, feedback appreciated, especially on your own setups and experiences, and don't forget the Steeple mailing list is a good place to talk about these things too.
Carl.
Footnotes:
^1) After some protracted back and forth with Epiphan's email support, we discovered their marketing claim for Quicktime is misleading - they support Quicktime 7 in 32bit mode (so 10.5 effectively), and Quicktime X in 64bit mode on 10.7, but have given up on creating a driver for 10.6. This is unfortunate, as we've found Quicktime 7 to be unstable (crashes very easily) on 10.6, and we're not in favour of putting 10.7 on these Mac Minis yet (mostly due to licencing and installation issues, and a lack of support in general).
^2) There are two cameras installed in the room, but only one has wiring that goes to the main AV cupboard, thus the second camera (which is in a less useful location) has been left to languish as it too suffers from the problems of the more central one (contrast and clarity).
^3) User beware again here. An undocumented bug in the current firmware (2.2.2b) means that using the ARU (automatic recording upload) function with a user password containing symbols is likely to cause it to fail without an clear warnings. Fail on the uploading that is, the rest carries on fine. Simplifying your password to contain just alphanumerics works around this, but won't impress some institutional password policies.
