Streaming Video on a Wireless Presentation System? What to Know.
Don’t confuse wireless screen mirroring with streaming. They’re two completely different things.
Every once in a while, we hear from a user who reports choppy video or dropped frames while streaming a YouTube video from a laptop or smartphone to one of our wireless presentation systems.
The expectation is that the video should play back as well on the big screen as it does on the user’s device. While that’s totally understandable as an expectation, it is virtually impossible in practice.
The proliferation of video streaming devices like Amazon’s Fire TV, ROKU, Google’s Chromecast, and more, has fundamentally changed the way people consume TV programming. For as little as $20, consumers get a wireless device that plugs into their TV and can stream 4K content from the Internet.
So why are these wireless screen-mirroring products, costing hundreds or even thousands of dollars, unable to do what a twenty-dollar streaming device can do?
Well, simply put, they’re designed to do two very different things. First, a little background. The digital data that makes up a video stream is sent in 'Packets'. These data packets are transmitted from one device to another over a network, be it local, or the Internet. Since those packets are sharing the network with other packets from other sources, sometimes collisions occur, preventing some from arriving at their intended destination. When that happens, the receiver sends a message to the server, asking for that packet to be re-sent.
When these re-transmissions are happening in real time, the video becomes choppy. The
image freezes, as the next packet is retransmitted, and the video continues. If this is the way all streaming video worked, what are the odds we’d ever see the explosion of
Internet video streaming? How about zero.
And that’s why streaming video systems use a technology that fixes the
problem; buffering. You've no doubt seen the dreaded icon.
Buffering simply means that instead of sending and displaying the content from each
packet as it arrives, we allow the packets to accumulate in a storage container—a buffer. Think of the buffer as if it were a water tank, feeding a faucet that needs a constant flow of water. Fill that tank, and if the water flowing into the tank is disrupted, it won’t affect the flow coming out of the faucet.
In the case of video streaming devices, the water tank is memory, and the water is data. And, because the source of that data is somewhere in the cloud, the user never sees its origin, only its arrival, as video on the screen.
Who cares how much of a delay there is between the origin and display? All that matters is high-resolution, fluid video, and buffering delivers.
While buffering data helps achieve the consumer’s requirement for smooth video playback, with no dropped frames, it is completely unsuited to real time screen mirroring. When you’re making a presentation, the most important element is synchronization between what happens on your device screen, and what you see on the big screen. Tap on a link, and see it load a different page. No, or absolutely minimal, delay.
Wireless screen mirroring products like KLIK, are designed to favor low delay—or latency—over smooth video playback. Our products’ mission isn’t streaming videos from the Internet; there are plenty of products that do that. KLIK is all about screen mirroring of content from a user’s device, in real time. As long as the network is up for it, our products will stream video, but low latency is our prime objective.
That's in sharp contrast to how video streaming systems work, for a couple of really important reasons. First, since videos are transmitted over the Internet, there are a lot more 'hops' for the data packets to make from the server to your TV. Each hop can introduce more latency, and require retransmission of several data packets, further delaying arrival of the video content.
Imagine a several-second delay between when you advance your presentation slides and when they appear on the TV in the meeting room. Disorienting to say the least. However that delay is irrelevant when you're streaming a movie from YouTube or your favorite streaming provider. Because you can't see when the video starts at the server, the latency is invisible to you. All you see is perfectly rendered video.
When viewed side-by-side, it becomes obvious that a wireless presentation system must have low latency and therefore no buffering, while a video streaming system must have data buffering and therefore long latency. In the former, everyone sees the start of the transmission, while in the latter, it is hidden from view. Both systems do what they're intended to, and neither is a substitute for the other.
One final note on the topic is that wireless presentation systems can in fact be used to stream video, with a couple of caveats. First, both the system and clients need to be connected to a robust network, preferably a wired network. At the very least the presentation system should be on a wired connection as Wi-Fi connections without buffering will seldom render satisfactory results.
The other important consideration is the actual video being transmitted. The higher the resolution and frame rate of the video, the more likely it will overwhelm the system and crash the system. If you're streaming the content from YouTube for example, choose the 720p stream, or even the 360p version for greater reliability.
Depending on the model of KLIK presentation system and how it's configured you can even stream at 1080p, but that's not guaranteed, so do some testing before you start an important meeting. It always pays to be prepared.
About KLIKBoks, Inc.
KLIKBoks was founded to solve the problem of how people share content in meetings, classes and conferences. From the company’s early KLIKBoks™ and KLIKStik™ wireless collaboration devices to the breakthrough patented technology found in the KORE™, KLIKBoks is still dedicated to fostering frictionless collaboration between people. https://klikboks.com/