Video within the EDU sector, and live streaming video in particular, are seeing dramatic surges in both utilization and return on investment. From flipping the classroom to increased student engagement to advancements in remote learning—we see video everywhere.
As educational institutions look to leverage live streaming video, the gaps between linear video production and live streaming video production become apparent. To allow you to stay focused on creating great content, and worry less about how that content gets produced, here are 5 things to consider to optimize your live streaming content for a Live-to-VOD (Video on Demand) workflow.
Live streaming can be done in a multitude of ways, but when you’re doing a live video there’s a good chance you will record it for playback later on. If your systems use proprietary encoding wrappers, it makes it harder to unwrap and grab high quality media from them for playback on the web.
Recording to a more well-known standard like .mp4 will make preparing it for the web much faster, as well as provide a generous level of compression before it gets transcoded by your Online Video Provider (OVP). This reduces file sizes and makes uploading faster when you aren’t recording to the cloud directly.
As you produce your streams, think about your audience and more specifically your content. If you stream or record a lecture with a professor behind a podium, or a still image of a PowerPoint which only changes every few minutes, you can achieve relatively high quality video streaming as slow as 24 frames per second (fps).
Increasing the frame-rate becomes important as your content becomes more action packed. For example, you would never stream a football game at such a slow fps due to all the movement by the players. Yet, with lecture capture, the image being captured usually stays quite still allowing high quality capture using fewer fps.
Your live stream is already being sent to the world via the cloud, so if possible it is best to record your stream to the cloud as well. This can optimize your end-to-end workflows by reducing upload time after the live stream has finished.
Even if you need to record to a remote cloud location, more times than not a server to server content transfer can be faster than a direct user upload from their computer.
In the most ideal scenario, try to record your source directly into your respective OVP or distribution platform. With Kaltura, for example, you can deliver a live stream to all of your end users and have a copy of your stream’s source recorded at the same time. Then, when your stream ends, your VOD recording is already immediately available for distribution on the web.
Similar to frame-rate, if the content is lecture-based or PowerPoint-based, you can record at a much lower bit-rate without losing quality
When the content you are recording moves faster, more bits must be replaced in faster succession. The more bits you have, the smoother the stream appears to be but the larger the file sizes become.
The standard rule of thumb for web transcoding is to record your source at 2x your highest playback bit-rate. So if you want to deliver video at a peak rate of 720p24 at 2.8mbps then your source should be 720p24 at a minimum of 5.2mbps. Keeping this initial bit-rate down can help reduce the time between the live stream ending and the VOD asset being available on the web.
If you are conscious of Content Delivery Network (CDN) and storage costs, be aware that each transcoded rendition has different financial impacts when it comes to delivering them to end users. When players use adaptive bit-rate technology, end users with higher bandwidth environments will suck up more bandwidth by pulling higher quality renditions.
Higher bit-rate renditions don’t just cost more to deliver, but they also cost more to store. If your content doesn’t require High Definition fidelity, consider only transcoding into Standard Definition renditions to save money. Or, only deliver at 720p instead of 1080p if you require HD playback for your content. This will still allow you to deliver an HD video stream, but remove the higher overhead of storing and delivering the 1080p HD video.
Not all content is created equal, and some content on a case-by-case basis might require higher quality playback than others. If this is the case for your organization, check with your OVP to see if you can configure multiple transcoding options that can be used for different types of content. This provides video-level optimization of both storage and delivery costs allowing you to pick and choose which content gets delivered and stored at which quality.