In the previous two articles written by my colleague Ben Larson, you learned about how packet loss and bitrate affect video quality. In the last article in this series, I will jump in to discuss some additional streaming techniques that can also have a big effect on the viewer’s video experience. If your company is planning on doing more internal video communications, as many companies now are, I’ll help you understand which circumstances call for the use of multi bitrate (MBR) techniques and which ones are better suited for adaptive bitrate (ABR) streaming.
Before I define MBR and ABR in more detail, let me first provide some context by setting the stage around the end-user’s experience. If you are like me, you could use some real-world examples to help translate and make sense of the technology.
The End-User’s Experience
Many of you use YouTube or another form of streaming entertainment service at home, such as Netflix, Hulu, HBO Now, Vudu, etc. These services leverage your home internet connection which, unless you have the top-of-the-line internet package, can fluctuate at any time during the day and for a variety of reasons.
Picture this: you just paid for the latest movie and are getting ready to watch it. The movie starts, you become absorbed in it, and just as the plot thickens, it starts to buffer. Ok, you can tolerate one buffering event, but it continues to buffer every time the movie is at what seems like a crucial part. Frustrating? Yes!
Some streaming services can adapt to a fluctuating internet connection so that you don’t get buffering. In this case, however, while there may not be buffering, your TV screen appears fuzzy. Now you may be inclined to move closer to the TV to decipher what is happening in the movie. Suddenly, everything appears clear. Minutes later, it becomes fuzzy again. Frustrating? Maybe not as much as buffering, but do you just resign yourself and decide to pay for the top-of-the-line internet package to solve the problem? What if you already have the best package?
What is MBR and ABR?
Back to defining the terms. Thinking about the above scenario, you may have had a choice at the beginning when you were selecting your movie to choose the hi-definition (HDX, HD) or standard definition (SD) format. Let’s say you decided to purchase the HDX version, or the highest quality possible (HDX video is streamed at 1080p and 24 frames per second). Your streaming service probably ran a background test at purchase time and determined that the HDX version will work on your network.
But the streaming service doesn’t know that 30 minutes into the movie, your kids and their friends all started watching YouTube videos over the same internet connection. The technical term for what you just experienced is MBR. With MBR, a few different streams, all with different bitrates, are made available to the user. As the user clicks Play, the system performs a test to determine which bitrate is best suited for their situation. Once selected, however, the system will keep using that bitrate even if the internet connection or bandwidth fluctuates.
With YouTube or Netflix, as opposed to pay-per-view, you select a video and watch it right away. Upon initial viewing, you may get one bitrate and as the internet connection fluctuates (kids, friends, other YouTube videos), the quality changes and usually becomes worse if the internet connection is heavily used. It will then change again minutes later once the internet connection is freed up (kids, friends have left the house). The streaming service detects the bandwidth fluctuations and automatically changes the bitrate for you so the movie continues without buffering. This is called ABR.
Streaming Inside Your Company
These definitions are a bit over-simplified, but I think we can all relate to them. Let’s now take this inside the corporate world. You are going to live-stream a large town-hall event to all employees world-wide. Instead of your kids and their friends messing with your internet connection, you are now dealing with mission-critical business applications, office productivity applications, Enterprise Resource Planning (ERP) applications, security systems, Voice over IP (VOIP), video conferencing, web collaboration, and the occasional employee checking out Facebook or watching YouTube videos. These are similar challenges to the ones at home, but at a much higher level of complexity and not as easy to solve like kicking your kids and their friends off your home WiFi connection.
With a software-defined enterprise content delivery (SD ECDN) solution, you can support both MBR and ABR to manage that large town-hall event to your global workforce even with all the challenges and demands on your corporate network. Some live-stream events may be better suited for an MBR approach; for example, known low-bandwidth locations may be better served with a predictable bitrate or quality. Other events may be better suited for an ABR approach; for example, a large campus that has intermittent, unpredictable bandwidth fluctuations, with users who expect the highest quality experience possible at all times.
This goal of this article trilogy was to provide a basic understanding of what can impact your live-streaming video experience. From packet loss to choosing the wrong bitrate to understanding MBR versus ABR, they all have a place in your live-streaming success. Kollective SD ECDN provides a software-based, video delivery foundation that can address each of the challenges described in this series. Don’t hesitate to contact us directly with questions or for more information.