An introduction to

We are all aware of the delay in video data transfer.

So what exactly is low latency? Are you looking to cut down on latency on all of your live event? Find out all the answers plus more in this tutorial.

A brief introduction to low latency

Low latency is the minimal delay that video data transfers from the player onto the screens of your viewers.

The shorter time for data transmission results in a better video experience, and also facilitates interactions. However, here's the problem: for low latency, it is necessary to sacrifice reduced video resolution or quality.

Luckily, no live event requires low latency.

This is necessary in live streaming events for real-time interaction or watching experience. When you live stream, your audience expects to keep track of what's happening and/or be a part of the action throughout the events. Therefore, you cannot afford to pay for the high-latency requirements and you will need to stream with less than 4K resolution.

While this is low latency streaming in its simplest form Let's get deep into the particulars of how and how to achieve it.

What is low latency

Translated, the term "latency" literally refers to a delay in transmission.'

In the context of video latency, this means the amount of amount of time that it takes for the video captured from your camera to it playing on your players' viewers.

Therefore, a low latency will mean less time in transferring video content from point A (your streaming headquarter) towards point B (your your audience's members).

Similarly, a high latency means more time in transmission of video data from live streamer's viewers.

What exactly is considered to be a low latency?

According to industry standards, low latency live streaming video has a duration of 10 seconds or less while streaming broadcast tv ranges from 2- 6 seconds. In the case of your particular use you may even reach ultra-low latency that lies between 2 - 0.2 seconds.

Why do you require low latency for video streaming? It's not necessary to have low latency for every live stream that you host. However, you will need it for all interactive live streaming.

It's all about how much interaction your live event needs.

So if your event involves, for example a live auction then you'll require a streaming with low latency. Why? To ensure all interactions show in real-time and not have delay, as this could result in unfair advantage.

Let's take a look at some of these use cases next.

When do you need streaming that is low-latency?

The greater participation in live streaming your event needs, the shorter transmission time you need. In this way, guests can take advantage of the event in real time without interruption.

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

• Two-way communicationsuch as live chat. This includes live events where Q&As take place.
• Real-time viewing experienceis vital, for example with online games.
• Required audience participation. This is the case, for instance, when it comes to cases of online casinos, bets on sports, as well as live auctions.
• Real-time monitoring. This includes, for instance, search and rescue missions as well as bodycams that are military grade, child and pet monitors.
• Remote operation that require consistent connection between distant operators and machinery they control. Example: endoscopy cameras.

Why should you choose to use low latency streaming

In summarising the scenarios we explored above You need streaming with low latency when streaming either:

• Content with a time limit
• Content that demands real-time audience interaction and engagement

But why not use low latency on all the video content you stream? After all, the lower the delay in your content getting to your viewers, the better, isn't it? Well, not exactly. Low latency does comes with drawbacks.

The disadvantages include:

• Low latency compromises video quality. The reason: high quality video slows down the transmission workflow due to its large file size.
• There's little buffered (or pre-loaded) information in the line. There's not much room for error should there an issue with the network.

If you stream live the streaming platform swiftly pre-loads some of the content prior to stream to viewers. In this way, if there's an issue with the network, it plays the content buffered, and allows the slowdown caused by network to catch up.

As soon as the issue with network connectivity is solved The player will download the highest possible video quality. However, all this occurs in the background.

In other words, viewers will enjoy continuous, high-quality playback experience unless, of course, a major error on the network occurs.

When you select a low latency, there's less playback video to be prepared by the player. There's a little chance of error when a network issue strikes from the blue.

That said, high latency comes handy in certain situations. As an example, the greater delay gives the producers opportunity to block vulgar content or inappropriate language.

In the same way, if there is no compromise in video broadcast quality, increase the speed of transmission to ensure the best viewing experience possible and have some room to adjust for errors.

How is latency measured

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

Technically, low latency is determined by a measurement unit known as the round-trip duration (RTT). It refers to the length of amount of time required for a packet to go from A to B and to be returned to the origin.

To calculate this, an effective way is to use the timestamps of video and then ask an associate to stream the live streaming.

Have them look for the exact time frame that will appear on the screen. Then, subtract the timestamp's time from the date the person saw the exact frame. That will calculate your latency.

Alternately, you can ask your teammate to follow your stream, and take a cue when it comes. Then, record the exact time that when you made the cue sound on live streaming and record the time your designated viewer saw the cue. It will provide you with the latency, but not as precisely like the previous method. But it's still good enough to get a general idea.

How to reduce video latency

Now how do you achieve low latency?

The truth is that there's a myriad of elements that influence the speed of your video. From encoder settings to streamer you're using, various factors play a part to play.

So let's take a look at these elements and the best way to maximize them for reducing streaming latency while making sure the quality of your videos don't suffer the biggest hit.

• Internet connection Type. Your internet connection is what determines your data transmission rates and speed. It's why ethernet connections are more suitable for live streaming than WiFi and cellular data (it's more beneficial to keep those for backups, however).

• Bandwidth. A high bandwidth (the quantity of data that is transferred at any given moment) is less crowded and faster internet.

• Size of video files. Bigger sizes require more bandwidth in transferring from point A to point B. This increases the latency and vice versa.

• Distance. This tells you how far you're from your internet source. The closer you are closer to the source, the more quickly your video stream will transfer.

• Encoder. Pick an encoder which helps you keep low latency by communicating signals through your device to the receiver device in the shortest period of time as is possible. Make sure the one that you choose is compatible with your streaming service.
• streaming protocol or the protocol that transfers the data you've collected (including audio and video) through your laptop to the screens of viewers. For achieving low latency, you'll need to select a streaming protocol that reduces data loss while introducing lower latency.

Let's look at the different streaming protocols that you are able to choose from:

• SRT It is a protocol that effectively sends video of high quality over long distances while maintaining low latency. However, since it's relatively new, it's still being adopted by tech including encoders. How can you solve this problem? Make use of it when paired with another protocol.

• WebRTC: WebRTC can be used for video conferencing however it has a few compromises on quality of video since it's focused on speed mostly. The problem, however, is that the majority of players aren't compatible with it as it requires a complex set up to be deployed.
• High-latency HLS This is ideal to use for latencies that are low, ranging from 1 2-seconds. This is why it's suitable for interactive live streaming. But, it's still an emerging spec so support for implementation is currently in the works.
  

Live stream with low latency

The streaming of low latency is possible with a fast internet connection, a high capacity, best-fit streaming technology, and an optimized encoder.

What's more, closing the distance between you and your internet and using smaller formats for video can help.