An Inexpensive Method for Recording Lectures Without Use of a Video Recorder
Results and Discussion
The lecture recordings made with this system in the classes of one of us (RG) may be viewed on-line using Internet Explorer with the QuickTime© Version 6 plug-in [8]. They consist of all the material presented on the screen, i.e., the PowerPoint slides and the annotations made on the slides using the digital tablet, and the audio captured from the lecturer’s microphone. These files have not been edited for content, only compressed and prepared for streaming, so they lack editorial polish. No presentation script was used – the prepared slides simply being presented serially with occasional digressions for “workshops” or detailed answers to questions from students.
The absence of a “talking head” in our recordings conserves bandwidth allowing for a 512 x 384 pixel widow and good clarity for broadband connections (DSL or cable modem). A smaller, but still usable, window (384 x 288 pixel) is provided for 56k modem users. The use of MPEG-4 compression is essential for the attainment of adequate video quality. Audio compression is also very important and the Qualcomm codec gave the best results [6]. A survey of student preferences at the end of the semester revealed that 45% of responding students viewed at least some of the streamed lectures.