We made a video which explains how adaptive streaming works. You can watch it here, or read about it below.
People often worry about using videos for training as they are mindful that video files can be very big, consume bandwidth and sometimes deliver jerky results. All of this can be true, but it’s not the whole story.
If you put a video file on a normal website, there’s one video which is delivered to all devices regardless of screen size or connection speed.
Here’s our Wellness video. It’s 5.20 minutes long and 162MB. That’s a good size for a video as it’s been compressed, but the same size video would get served to all the different devices.
Here you can see our Wellness video on YouTube.
Video hosting services like YouTube, Vimeo, and Wistia use what’s known as adaptive streaming to deliver videos more efficiently.
Adaptive streaming (also known as adaptive bitrate streaming) is a technology designed to deliver video to the user in the most efficient way possible and in the highest usable quality for each specific user.
How does it work?
When a video is uploaded, it creates a number of different versions of the video – to fit different screen sizes and so that it plays smoothly with different connection speeds.
The software basically decides the answer to three questions:
- What kind of device is it?
- What’s the connection like?
- Which is the best video to use?
When it has answered these questions, it serves the most appropriate version of the video to the device.
Here’s the adaptive bit.
Each video is split into chunks that are about 4 seconds long (this can vary). If the software detects that the connection speed has dropped, it will deliver a better suited video.
If the connection speed then changes and gets better, it ‘adapts’ and sends a better quality video.
In other words, the software keeps asking the last two questions.
The viewer is unlikely to spot any change, but the video plays smoothly. It’s the way YouTube works (and wouldn’t work nearly so well without it).
If you select the Settings buttons on a YouTube video, you can choose which size video you want to view. Try it now https://youtu.be/UgizCwaeFZs the video will open in a new tab. Choose the Settings cog (bottom right when you roll the cursor over the video), then select Quality and you’ll see what I mean.
Most often it’s set to Auto which lets the adaptive streaming do its job.