Semi-automated Mass Production of E-Learning Content

CESNET technical report number 29/2005
also available in PDF, PostScript, and XML formats.

Ivan Doležal, Eric Sullivan
19. 12. 2005

Now that educational organizations have discovered the value of using e-learning tools for their educational processes (especially in the field of the distance learning) it is time, while the initial e-learning hype calms down, to provide rational answers to the following questions: How to produce the valuable content for a modest price in a reasonable amount of time? Which technical standards to adhere when many are called, but few are chosen?

An expansion of VŠB - Technical University of Ostrava, with freshman survival classes in mind, brought in a perfect technological background to help answer these questions. It started, surprisingly, by rebuilding an old municipal cinema into an auditorium with 500 seats and a literally big screen (7×16 meters) instead of blackboard. The blackboard was replaced with a powerful data projector, the GTCO CalComp InterWrite electronic whiteboard and a PC running special software to control the whiteboard was installed into a pulpit. Presenters can display their own presentations using either the installed PC, their own device with xVGA output, from DVD or from VHS. Another option is to use plain old pen and paper captured by a CCD video camera. Lastly, there was a quality PA system used by all speakers (excellent professional wireless sets Sennheiser Evolution G2 100 Series with lavaliere mics) which guaranteed a well received audio. It was only a matter of time to try to get the most out of this configuration.

The next step was to decide on a video standard. In today's plethora of video standards the Microsoft's "Windows Media 9" seems to be everyone's pet and the solution with viable perspective - from software producers to chip manufacturers to independent standardization bodies (SMPTE). Users can play it mostly without the problem of having to install special software; content producers can rely on it as a mature technology.

Building on this standard, the simple solution that is proposed here is to archive (save) the output of presentation devices plus speaker's voice in a pure standardized video format using Windows Media Encoder ("WME").

Finally, an automated process at a reasonable cost needed to be developed in order to handle the everyday live streaming and/or archiving of papers and presentations in a robust manner and preferably without human intervention and available 24×7. Although there are already solutions for archiving presentations commercially marketed (Mediasite), these are very expensive and/or require specific client technologies (Microsoft Internet Explorer, installation of licensed codecs etc.). Surprisingly, no equivalent free solution was known to the authors.

It was therefore necessary to develop, in-house, a prototype application "AutEnc". Its main features are:

• Set all encoding parameters of the Windows Media Encoder
• Start and stop live streaming and/or archiving according to a 2-week periodical schedule (the way classes are usually scheduled)
• For on-line streaming, play out an "intermission" stream between papers (or when a paper isn't available for the live streaming).

Although originally it was meant to be a simple scripting project, it had to be rewritten into C++ programming language to explore all the potential of the WME API.

The configuration is very straightforward, using only one plaintext file and one encoding parameters file (native for WME). The plaintext file is quite self-explanatory:

Semester: Winter 2005 ¹
StartDate: 01.10.2005 ²
EndDate: 15.01.2006 ³
FirstWeek: EVEN ⁴
VideoSettings: vesmir.prx ⁵
BroadcastMethod: Pull ⁶
Mon EVEN 9:00 10:30 [Linearni algebra] [Jiri Vrbicky] Archiving: YES linalg_%m_%d­_%H_%M.wmv Broadcasting: YES linalg ⁷
Mon ODD 9:00 10:30 [Matematicka analyza] [Zuzana Moravkova] Archiving: YES matanal_%m_%d_%H_%M.wmv Broadcasting: NO - ⁸
HOL 25.12.2005 [Vanoce] ⁹
EXT 28.3.2006 10:00 12:00 [Zasedani vedecke rady] [-] Archiving: NO - Broadcasting: YES rada ¹⁰

Line 1 is informative.

Lines 2 and 3 specify the time of validity of the file.

Line 4 specifies, according to the official schedule of an academic year, whether the first week of classes should be considered "even" or "odd" (this must be explicitly specified).

Line 5 tells the WME where to get the encoder configuration.

Line 6 specifies the broadcasting method: "Pull" means Windows Media Server ("WMS") getting data from WME, "Push" - WME actively pushing the content to WMS.

Lines 7 and 8 specify two regular classes "Linear algebra" by Mr. Vrbicky and "Mathematical Analysis" by Mrs. Moravkova - this information will appear in WMV metadata attributes "Title" and "Author". Both should be archived to the files with names constructed from constant strings and time. Only Linear algebra should be broadcasted. In case the application runs in "Push" mode, "linalg" would be the publishing point; it is not used in "Pull" mode.

Line 9 specifies holidays (HOL is a keyword) - Christmas. Even if there was some "regular" scheduled transmission, holidays have higher priority and no scheduled transmission and/or archiving will happen.

Line 10 specifies an extra event (EXT is the keyword) that should be processed. Extra events have higher priority than holidays, i.e. these are processed even if there is a holiday.

If there is nothing to live stream, a prerecorded intermission file is transmitted (its filename as well as the schedule.txt filename is currently hard coded).

Figure 1:

The AutEnc application itself is represented by only one AutEnc window (shown here) plus a running instance of WME. The authors didn't feel any need to hide the original interface of WME itself: WME's interface displays an audio level meter (not available in any other manner), encoder statistics, visual control of input and output, but it won't let you control it from its own interface.

AutEnc allows limited human intervention: if a class starts earlier than planned, it is possible to start or stop archiving and/or streaming earlier thru a small dialog interface. In automated mode it fully relies on a real time clock of the encoding server. Therefore it is recommended to pay attention to its time synchronization (for example with NTP).