Echo360's EchoSystem is a lecture capture system. The practice of recording university lectures has a fairly long history, dating back to at least the 1970s. From that time until very recently the amount of work involved to produce a single recorded lecture had been substantial. Technicians were required to set up the recording equipment, operate it and manually edit the tape and produce a copy for the students, for each and every lecture. Even a simple audio recording required significant effort.
As digital technology has progressed the amount of time required for each of these stages has reduced. It has also allowed for capture of additional elements, such as video of the lecturer and recordings of what they are showing on screen. The EchoSystem brings all of these elements together, generating one synchronised recording, and is an evolution of a previous product called AnyStream Apreso.
How does the EchoSystem work?
The EchoSystem consists of a number of elements that come together to form a complete system. At the core of the system is the EchoSystem Server (ESS), which handles scheduling information, directs processing tasks and acts as a repository for the finished lectures. The ESS also directs the operation of the recording devices. These can be PCs on which the EchoSystem Capture Software has been installed, or dedicated devices called EchoSystem Capture Appliances: small, rack-mountable units with a number of audio and video inputs, USB and Ethernet ports, and an internal hard disk. These appliances run a Linux kernel optimised for embedded systems. The EchoSystem Processor is a software component that combines the audio and video files created by the Capture Appliances with timing information and other metadata, to produce web-optimised Flash video. The Processor can be installed on the same machine as the ESS, but Echo360 recommends one or more installations on separate servers to optimise the conversion workload. The Processors return the completed presentations to the ESS for delivery to the users, either through the ESS alone, or with the assistance of external web and flash streaming servers. The EchoSystem provides a number of mechanisms for publishing the content: through the institutional Virtual Learning Environment (VLE); iTunes U; or an RSS feed.
The rear of a Capture Appliance (pictured) has VGA pass-through to capture input to a digital projector, composite and S-video inputs to capture the output of a video camera, RCA phono and 1/4 stereo jack to capture audio, and four RJ-45 Ethernet ports for communication with the ESS. The device can act as a 4-port 10/100 Ethernet switch in locations with limited network connectivity.
Figure 1: Rear view of a capture appliance showing the audiovisual connections.
Recorded lectures can be distributed to students using a number of different methods. The lecturer automatically receives an e-mail when a recording is ready to be distributed. A link to the recording can then be provided to students, either by forwarding the e-mail, or by publishing the link on a web page. Alternatively, the lecturer can make RSS feeds available. The best solution, however, and the most fully automated, is to use one of the VLE integrations provided by Echo360. The EchoSystem currently integrates with Blackboard, TWEN, ANGEL and Moodle, automatically placing links to the recorded lectures in the calendar of the relevant course.
When using the VLE integration, students are presented with a number of media options (if configured at the scheduling stage) including rich media presentation, podcast, enhanced podcast and vodcast. All of these are presented to students in the browser, together with download links for the podcasts and vodcast. If students choose to view the rich media presentation they are given an additional choice of whether to view a presentation optimised for high speed connections, low speed connections, or a screen reader version. In the low speed version, the video of the lecturer will not be displayed; in the screen-reader version, links to chapters are provided for voice navigation.
The Rich Media presentation (Figure 2) consists of a web page made up of three frames. The main frame shows whatever is displayed on the classroom lecture theatre projector; in most cases this will be PowerPoint slides. If video of the lecturer is available this is shown in the top left frame. The bottom left frame contains thumbnail images of the main display frame, allowing the student to jump to almost any point in the lecture. The thumbnails are automatically generated based on the percentage image change on the main display. If there is no image change a new thumbnail will be created at a predetermined interval. There are also a number of buttons that allow students to change the arrangement of frames so that, for example, the video is displayed in the largest frame and the projected image is displayed in the smallest frame. It is also possible to view a slide sorter view by clicking on one of these buttons.
Figure 2: Example of the Rich Media presentation display showing video of the lecturer with accompanying slides.
For students, there are no system requirements other than version 9.0.0 or higher of the Adobe Flash browser plugin. Supported web browsers include: Internet Explorer 6 and 7, and Netscape 8 on Windows; Safari 1.3 and 2.0 on Mac OS 10.x; and Firefox 2 and 3 on Windows, Mac and Ubuntu 6.06, 7.04 and 8.04. Indeed the only explicitly unsupported configuration is Safari on Windows.
Administration and scheduling
Having installed the ESS software on your target server, the first task is to register the Capture Appliances with the system. This is as simple as saving a configuration file on a USB flash memory device, plugging it in to the Capture Appliance and switching it on. Within a minute, the new appliance will appear in the list of devices in the ESS. Each appliance is identified by the Media Access Control (MAC) address of its network card. To assist with identification and scheduling, each appliance is usually assigned to a room, i.e. the lecture theatre or classroom in which the appliance will be installed.
Once the devices are registered and installed in their rooms, scheduling can begin. Schedules are linked to terms, which can be semesters or an entire academic year; courses, which can be identified by name and course code, and are divided into one or more sections; and rooms, which allow you to identify the capture device without needing to know its MAC address. Schedules can be one-off events or recur at a specified interval, and are linked to one or more users called presenters, to whom the recording will be attributed in the title. The presenters will also receive an email advising them of the presentation's availability once processing is complete.
Schedules have products associated with them, which can be the full, "rich media" presentation consisting of slides, video and audio, and several presentations optimised for portable devices. These are podcasts: simple mp3 audio files; enhanced podcasts: m4b files containing the audio, mpeg-encoded slides and bookmarks to assist navigation; and vodcasts, m4v files containing the audio and video of the slides. The enhanced podcast and vodcast differ primarily in the temporal resolution of video transition: the vodcast would more accurately capture the output from a visualiser, for example.
Finally, schedules can be associated with one or more publishers. The email publisher sends an email containing links to each of the products to the presenters. The RSS publisher generates an RSS feed for inclusion in any web resource. There are also a number of publishers that will create resources in Blackboard CE, Enterprise and Vista, TWEN, ANGEL, and Moodle.
The EchoSystem Capture Appliances also support ad-hoc recording, which can be triggered through a web-based administrative interface, or through an API.
The ESS provides a number of options for monitoring the application. A monitor screen (Figure 3) summarises the current state of the system, including current captures, upcoming captures, free disk space on key volumes, and the status of capture stations. Capture station indicators include the time since the device last contacted the ESS, and the status of the audio, VGA and video inputs.
Figure 3: Monitoring screen available in the EchoSystem
Users can be assigned up to four roles in the ESS: presenter, A/V Technician, Admin and Server Administrator, each having different capabilities in the system. System alerts can be sent by email to users with certain roles. For example, when a capture device registers one of its inputs is missing, an email can be sent to users with the A/V Technician role. Likewise, when disk space is low, an alert can be sent to the Server Administrator.
Authentication and authorisation
It is possible to restrict access to presentations by linking the system to an LDAP (Lightweight Directory Access Protocol) directory such as OpenLDAP or Microsoft Active Directory. Security is set at the section level, so some presentations can be world-readable while others are restricted. EchoSystem supports multiple LDAP configurations so you can restrict access to users from different institutions or LDAP groups. Note that, by default, the login screen is accessed through port 8443 rather than the usual HTTPS port 443. This port needs to be open at your perimeter firewall, and in the firewalls of any other institutions from which your presentations will be accessed.
Architecture and system requirements
The EchoSystem's architecture differs from Echo360's previous product, AnyStream Apreso. Instead of using fully-featured PCs on which the capture and media processing software is installed, from which completed presentations are uploaded to web and media streaming servers, EchoSystem Capture Software or Capture Appliances upload H264-encoded video and AAC-encoded audio files to the ESS. These are then handed off to the Processors, which return web-optimised Flash video. The ESS then makes these available to web and media streaming servers for delivery.
Although it is possible to run the ESS, Processor, Web and Flash servers all on one server, performance suffers as an installation scales. The greatest performance benefits are achieved by adding Processor servers, but for large installations, separate Flash and Web servers are also recommended, as in Figure 4 below:
Figure 4: Recommended system architecture for the EchoSystem
Disk space is the greatest single requirement of the EchoSystem. Although Echo360 have worked to improve compression of master files through successive versions of the product, you will require 100 MB per hour of audio presentations, and up to 650 MB per hour of rich media presentations. If you are able to connect your ESS to a NAS (Network-Attached Storage) or SAN (Storage Area Network) with plenty of available space, so much the better.
Storage requirements will affect your choice of operating and file systems. For example, versions of the Windows Server operating system prior to 2003 Service Pack 1 cannot address NTFS volumes larger than 2 terabytes (TB). With Windows 2003 Service Pack 1, this increased to 256 TB. 64 bit versions of the Linux kernel can address XFS volumes up to 8 Exabytes (EB), while 16 TB is the maximum for 32 bit versions.
Version 2.4 of the EchoSystem introduced a mechanism to allow the deletion of master files after a specified period. This significantly reduces long-term storage requirements, but once these files have been deleted it is no longer possible to edit presentations.
Finally, it follows that a fast, low-latency LAN with short network distances between the components of your installation EchoSystem is a significant advantage.
Student and teacher feedback
Student reaction to lecture capture is overwhelmingly positive. Some students have even claimed that they could not have passed their exams without the ability to review their lectures. It is particularly helpful to students whose first language is not English. Language skills invariably improve throughout the course of study, so an opportunity to return to material presented early in the course is extremely beneficial. Lecture capture was the focus of a Student Union campaign to request that it be extended to all lectures throughout LSE; and, as with any IT service, you can get a good idea of its value to the students during any outage periods.
Reactions from lecturers are predictably mixed, though initial reluctance to be recorded and concerns regarding student attendance have largely been overcome. Dr Tim Leunig, who teaches a large-cohort Economic History course at LSE, has said: "The big fear is that you will end up speaking to no one, and that is absolutely unfounded. Good students turn up to lectures and listen again." Indeed a number of students have elected to be examined in Dr Leunig's course even though they cannot attend any of the lectures due to timetable clashes. They are happy to watch all the lectures online, in their own time. Dr Leunig continues: "Lecture capture has an extremely high benefit-to-cost ratio, because it's extremely popular and is virtually no effort." Indeed, beyond remembering to wear a clip-on microphone, there is nothing for the lecturers to do once they have granted their permission to be recorded.
The nature of the product makes it difficult to compare with the competition. It's not just a piece of software that one can download and test. We can, however, compare it with the company's previous product, Apreso. The EchoSystem is a far more ambitious product than Apreso; where Apreso was a small collection of software interfacing between standard hardware components, EchoSystem employs custom-designed hardware integrated with a Java-based server. Its cross-platform credentials are thus superior: Apreso's scheduler was a Windows-only product, while the EchoSystem's administrative interface can be viewed in a browser. Where Apreso generated Windows Media Video files, the EchoSystem provides Flash video, compatible with a broad range of personal computing platforms.
The reviewers started using EchoSystem as soon as it was released, effectively testing a "1.0" product. Predictably, we experienced teething problems with both software and hardware, and adapting to a new system architecture was a challenge. These initial problems have largely been ironed out. However, a few minor annoyances remain. We hope these will be resolved in time for the next academic year.
One area that has consistently been lacking since the days of Apreso is the generation of RSS feeds. EchoSystem produces an RSS feed for each scheduled course, containing links to each lecture that is recorded. Unfortunately, the RSS feed contents seem a bit haphazard. Firstly, the feeds lack title and description elements. Secondly, while using a sophisticated RSS feed reader such as Google Reader is fine, the Moodle RSS client (based on MagpieRSS) only lists items by the title element, which is identical in each, e.g. "EC101 Introduction to Economics Lent Term". We have repeatedly asked Echo360 to include the date of recording in each item title as a cue to the students, but this is one area where they have not been responsive. Finally, the feeds do not validate when checked against the W3C feed validation service.
Another frustration is that the Moodle integration doesn't quite work for formats other than rich media. MP3, M4U and M4V "files" are in fact HTML pages containing <embed> and <object> tags, rather than the actual media themselves. The pages provide links to the media files, but being HTML they break the embedded media player in Moodle. It would be better (i.e. normative) to provide direct links to the media, allowing the user's operating system to select the appropriate media handling application.
Finally, some areas of the administration interface still have a slightly unfinished feel. The content filtering options are not consistent: you can search for presentations, schedules and users, but not courses. Elements in drop-down filter lists are not sorted alphabetically, compromising their usefulness.
Of course, while we still have gripes, we must emphasise that this product is a huge achievement, greatly enhancing our ability to scale lecture capture across an entire institution. On the whole, it works reliably and produces what is becoming an indispensible resource for the students. There are even rumours of some teachers watching their own lectures to help improve their teaching, which can only be a good thing.
London School of Economics and Political Science
CLT Systems Manager
London School of Economics and Political Science