Since the launch of YouTube in 2005, limits on video distribution have been minimised and eliminated, while the capture and distribution of in-class materials has sky-rocketed. Likewise, technologies dedicated to lecture capture have grown alongside demand. In 2016, it was estimated that the dedicated lecture capture market was a $126.2m industry, expected to double in size by 2021. Typically there are multiple points of focus in the classroom, thus capturing multiple sources with switching and/or mixing has made sense. The lecturer and their movements and gesticulations are often a crucial visual cue for students, and a camera capturing student questions could also be important. Professors are also reliant on supporting material to aide their teaching with doc-cams, models, videos and most crucially, PowerPoint-style presentations serving as the basis of many lessons.
The Case for Multi-Stream
With switching/mixing requiring a dedicated body in the classroom (often the lecturer needing to decide when to switch inputs), or a post-production editor mixing multiple sources, offering options to the viewers to allow each individual to personalise their viewing and learning experience makes sense. Interested in reading the fine print of the slides? Switch to a feed of the onscreen lecture materials. The professor is getting excited? Switch dynamically to picture-in-picture mode to keep an eye on the action. Need a better view of the model being discussed? Switch the doc-cam feed to fill the screen, until it is time to switch back to the slides. Kaltura, Ensemble, Presentations2Go, and Panopto – major players in the lecture capture and distribution market – have identified this need for flexibility and viewer control, and all are offering a version of a multi-stream player within their platforms.
Working with Multi-Stream
When choosing an encoding/recording option for multi-stream, there are a few key features needed to make this process fluid and easy to operate for students, lecturers and IT administrators alike. Firstly, multi-stream requires multiple inputs; for the moment, this is often just two inputs, one for presentation materials and one for a camera. Most often, PowerPoint material will be coming from a system with the ability to transmit HDMI. In terms of the second input, with both HDMI and SDI cameras on the market, it may be best to base the decision on existing equipment. If however, the hope is to remain as flexible as possible, there are devices offering a second, configurable HDMI or SDI input. Secondly, because computers typically work at
60 frames per second (fps) and cameras often capture at 25 fps (in Europe) or 29.97 fps (in North America), over time video captured and streamed from these sources can drift and fall out of sync. To ensure a top-notch experience, the two sources need to live in perfect sync; there is nothing more distracting – and therefore dangerous to learning – than audio that does not match the video. Lastly, the encoder of choice should offer several different production modes, such as picture-in-picture or side-by-side, as certain layout configurations may make better sense depending on the content at hand.
Moving Forward with Multi-Stream Lecture Capture Capabilities
At the end of the day, the key elements of lecture capture depend on each school’s individual needs. There are however considerations that can make a major difference and by keeping these in mind, the educational institution can drive a better lecture capture experience: 1. Make it multi by ensuring that the device on hand has dual encoding capabilities. Prioritise user experience by putting the choice for picture-in-picture, side-by-side, or others in the hands of the students and professors so they see what they want, when they want—affording optimal audience engagement. 2. Ease of integration is king, with simple integration into existing VMS/ LMS and especially with set-and-forget scheduling options. Bonus points for APIs that offer deeper levels of customisation to the educational institution. 3. Flexibility in terms of saving, storing and archiving content. A simple archiving process saves content to a variety of possible storage locations and/ or stores and forwards content to ensure the local storage never reaches capacity. 4. When thinking about multi, look for an encoder that has frame synchronisers to ensure the differing frame rates of video sources remain perfectly in sync at all times and deliver the ultimate viewing experience.
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