A New Tool for Webcasting- The Mediasite

by Desmond K L Chan

In the old days, when we tried to make the video experience realistic and enjoyable, panning the camera back and forth between the presenter and the projection screen was unavoidable. This inevitably degraded the quality of video capture. Luckily, we have tools available now to make presentation capture easier and look better without using this “point the cam at the screen” trick!


In view of this, CityU recently acquired a new tool called Mediasite capturing suite from Sonic Foundry. This is also called a webcasting platform because it synchronizes the audio and video recordings of the presenter with his/her captured slides to deliver a single rich media presentation which viewers can watch through the Web.

What can the Mediasite do?


(A) Capturing presentation for live webcasting


The Mediasite system can capture and record three elements of a live presentation:

  • Video capture of the presenter,
  • Computer display, say PowerPoint slide show, and
  • Presenter’s voice.


The system takes these elements and assembles them into a single web-based presentation that can be synchronized with the PowerPoint presentation slide show. Watching a presentation is virtually the same as being in the room with the presenter. Viewers can keep up with the pace of the presentation easily since the video, audio and visual aids are synchronized in real time as the presenter speaks.


Viewers can join before the presentation begins or after it has started. The Mediasite player also includes separate controls to navigate and adjust the video and slide show portions of a presentation based on viewers’ preferences. Viewers can also interact with the presenter through polls and Q&A.


(B) Capturing presentation for on-demand webcasting


With on-demand webcasting, viewers cannot actively interact with the presenter, however, they can flexibly scroll through any part of the video by dragging on the timeline or clicking the slide corresponding to the part of the video. Also, viewers can focus on either the speaker or the PowerPoint slide as the centre of attention. The classic media player, as illustrated in figure 1 below, shows a screen layout inside an internet browser window, where the PowerPoint slide has a much larger and more prominent view than the video of the presenter.


Figure 1a: Mediasite classic player to view live or on-demand webcast (sorted slide view)



Figure 1b: Mediasite classic player to view live or on-demand webcast (full slide view)

Benefits of using Mediasite


The use of Mediasite can benefit both viewers and technicians. For viewers, the captured slides are synchronized with the video, enabling them to quickly select exactly the part of the presentation they want to watch by clicking on the respective slides. This saves viewers a lot of time from searching the whole video for their desired topics. This cannot be done if only a timeline is provided which many other kinds of capturing equipment are still offering.


For technicians, one of the many important benefits is that Mediasite provides a complete capturing solution with a quick and easy set-up. These two factors are crucial since the rehearsal time before webcasting functions is normally very limited.



Potential Usage of Mediasite


(A) Capturing lecture for students’ review


Mediasite can be used as a lecture capture system which offers three important benefits: provides an alternative when students miss class due to illness or travel requirements; an opportunity for content review, particularly when complex topics are introduced or detailed procedures are performed; and obtain content for on-line course development accompanying with back-end servers to form a contents administration system.


(B) Capturing and broadcast live functions

From time to time, some functions held on campus are required to provide an on-line option for the viewers. This can be achieved by using Mediasite no matter the required webcast is a live or on-demand event.


Before products like Sonic Foundry's Mediasite came on the scene, capturing the presenter's computer screen and voice along with full-motion video of the presenter required a lot of manpower with scan converters and video mixer or switches. Now with the Mediasite installed, we simply need a camera video, the presenter's voice, and VGA video from the presenter's computer. This dramatically reduces the complexity of video capture as needed before and changes the viewers’ experience in a more user friendly way.