A beginner's guide to

Many of us are acquainted with the delays in video data transfer.

So what exactly is low latency? Are you looking to cut down on the latency of all live events? Let's answer all this plus more in this tutorial.

An introduction to low latency

Low latency is the minimal delay in video data transfer between your player and your screens for viewers.

The lower time to transmit data results in a better viewing experience and facilitates interaction. Here's the thing to get low latency: you must compromise on less resolution or better quality video.

It is a good thing that no live event requires very low latency.

This is necessary when you live stream activities to allow for real-time interaction and watching experience. In these cases, your audience expects to see what's going on or participate in the live stream during the course of the event. Therefore, you cannot afford to pay for the high-latency requirements and you will need to stream at smaller resolutions than 4K.

Although this is low-latency streaming, let's dig deep into the particulars of how and how you can achieve it.

What exactly is low latency?

Translated, the term "latency" literally means 'a delay in transfer.'

For the purposes of video latency, it refers to the length of duration of the footage you have taken from your camera to play on your players' viewers.

Therefore, a low latency will mean reduced time to transfer video data between point A (your headquarters for streaming) and to the point of B (your viewers).

Similar to that, a higher latency can mean more transmission of video data from live streamer's audience to the.

What exactly is considered to be as a low latency?

According to industry standards, the minimum latency for live streaming is less than 10 seconds while broadcast television streaming is from 2- six seconds. Depending on your use case and requirements, you can attain ultra-low latency which lies between 2 and 0.2 seconds.

But why do you need the lowest latency when streaming video? You don't need low latency for every live stream that you host. However, you will need it for each interactive live streaming.

It's all about the amount of interaction that your live event needs.

If your event is such things as an auction live, you'll need low latency for your stream. Why? to ensure that all interactions are displayed on time - and without the possibility of delays, which could cause some users to gain an unfair advantage.

Let's look at more of these scenarios later.

When do you need streaming with low latency?

The more live participation your event requires the less transmission time you will require. This way, attendees can live-stream the experience with no interruption.

Here are instances when it is necessary to stream at a low-latency:

• Two-way communicationsuch as live chat. This is also true for live events in which Q&As take place.
• Real-time viewing experienceis vital, for example with online video games.
• Requires audience participation. In the case of casinos online, gambling on sports and auctions that live.
• Real-time monitoring. For example, mission to search and rescue bodiescams of military level, child and pet monitors.
• Remote operation which require constant connections between remote operators and the machinery they manage. Example: endoscopy cameras.

Why should you choose to use streaming with low latency?

In summarising the scenarios which we've previously discussed, you need low latency streaming when streaming:

• Content that is time-sensitive
• Content that requires immediate audience interaction and participation.

But why not use low latency for all your videos? The more efficient the time your video content takes getting to your viewers, the better? Well, not exactly. Low latency does comes with drawbacks.

They include:

• The low latency can compromise the quality of video. Why is this? High quality video slows down the process of transmission due to the high file size.
• There's little buffered (or pre-loaded) content in this line. This leaves little space for error should there occur a problem with your network.

If you stream live the streaming platform rapidly preloads content prior to stream to viewers. This way, when there's a network problem, plays the content buffered, and allows the slowdown caused by network to be remediated.

As soon as the issue with network connectivity is solved when the issue is resolved, the player downloads the top quality possible video. All this, however, occurs in the background.

The result is that viewers receive continuous, high-quality replay experience unless, in the course of events, a serious incident occurs on the network.

When you opt for low latency, however you'll see less replay video that the player prepares. It leaves little room for error when the network issues strike out of the blue.

That said, high latency is useful in some situations. As an example, the greater time lag gives producers the opportunity to block insensitive content as well as profane.

In the same way, if there is no compromise in the broadcast quality of your video, raise the speed of transmission so you can offer the best viewing experience possible and have some room to adjust for errors.

What is the measurement of latency?

With the definition of streaming with low latency and the applications for it out of the way we'll look at ways you can gauge it.

Technically, low latency is measured with a unit called the round-trip duration (RTT). It is the amount of duration it takes for a data packet to move from A to B and to return back to the origin.

For calculating this number, an effective way is to use video timestamps and ask an associate to stream the live stream.

Ask them to look out for the exact time frame that will appear on their monitor. Now add the timestamp's duration from the moment the user saw the exact frame. This gives you the time of arrival.

Alternatively, ask a teammate to watch your live stream and record a particular cue whenever it occurs. Then, record the exact time that you played the cue in your live stream, and note when your assigned viewer saw the cue. This should give you latency albeit not as accurately like the previous method. It's still enough for a rough idea.

How can you reduce the latency of video?

Now how do you achieve lower latency?

The truth is that there are several variables that affect the latency of video. From the settings for encoders to the streaming protocols you're using several factors have a role to play.

So let's look at these factors and the best way to maximize them for reducing streaming latency , while ensuring that the quality of your videos don't suffer an enormous hit.

• Internet connection form. The internet connection determines your speed and data transfer rates. It's why ethernet connections are more suitable to stream live than wireless and cell data (it's more beneficial to keep those for backups, however).

• Bandwidth. High bandwidth (the quantity of data that can be transmitted at one period of time) results in less congestion and more speedy internet.

• Size of video files. The larger sizes consume much more bandwidth for transferring video from point A to point B, which can increase speed and also the duration of.

• Distance. It's how far you are from the internet provider. The closer you are, the faster the video stream you upload will be transferred.

• Encoder. Select an encoder that helps to keep your latency low by transmitting signals through your device to the receiver device in as short a duration as you can. However, make sure that the encoder that you choose will work with your streaming service.
• Streaming protocol is the protocol that delivers the data you've collected (including audio and video) from your workstation to viewers' screens. In order to achieve low latency you'll have to choose the right streaming protocol to minimize data loss and introduces less latency.

Let's look at the protocols for streaming that you could choose from:

• SRT The protocol efficiently transfers high-quality video over long distances at very low latency. Since it's recent, it's not yet used by technology, including encoders. How can you solve this problem? Combine it with an alternative protocol.

• WebRTC: WebRTC is an excellent video conferencing tool but it does have some compromises on quality of video since it's focused on speed mostly. But the problem is that the majority of players don't work with it as it requires an elaborate setup to be deployed.
• Low-latency HLS is great to use for latencies that are low, ranging from 1 two seconds. This is why it's perfect for live streaming with interactive features. But, it's still an emerging spec so implementation support is in the works.
  

Live stream with low latency

The streaming of low latency is achievable with an extremely fast internet connection, a high bandwidth, the best-fit streaming technology, and an optimized encoder.

Additionally you can reduce the distance between yourself and the internet, as well as using smaller videos can be helpful.