The beginner's guide to low latency streaming

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

What exactly is low latency? Do you need to reduce the latency of all live occasions? Let's answer all this and more in this guide.

A brief introduction to low latency

Low latency refers to the smallest delay that video data transfers between your player and the screens of your viewers.

The reduced data transmission time provides a great watching experience as well as facilitating interaction. However, here's the problem to get low latency: it is necessary to sacrifice lower resolution or video quality.

Luckily, not every live event demands low latency.

It is essential when you live stream events to provide a live interaction or watching experience. If you're doing this, your audience expects to be able to watch and/or participate live during the course of the event. Therefore, you cannot afford to pay for high latency and will have to stream at lower than 4K video resolutions.

This is low latency streaming we'll go into the details of when and how.

What is low latency

In its literal meaning, the word "latency" is a term that means "a delay in the transfer.'

In the context of video latency, this means the amount of duration of the video captured from your camera until it is played in your viewers' players.

Hence, low latency means reduced time to transfer video content to point A (your headquarters for streaming) towards point B (your viewers).

Similarly, a high latency will take longer for streaming video data from the live streamer's audience to the.

What exactly is considered to be as a low latency?

Based on industry standards, low latency live streaming video has a duration of 10 seconds or less while streaming broadcast tv ranges from 2- six minutes. In the case of your particular use and requirements, you can achieve ultra-low latency, which is between 2 - 0.2 seconds.

But why do you need the lowest latency when streaming video? It's not necessary to have high latency on every live stream you host. You do require it for all live, interactive live streaming.

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

So if your event involves like auctions live then you'll require a streaming with low latency. Why? In order to make sure that every interaction is in real-time and not have delay, as this could give some participants an unfair advantage.

Let's take a look at some examples of these usage cases later.

When do you need low latency streaming?

The more participation live your event requires, the shorter transmission duration you require. This way, attendees can enjoy the experience in real-time without interruption.

Here are instances when you'll need low latency streaming:

• Two-way communicationssuch as live chat. This includes live events where Q&As are involved.
• Live-streamed viewingis vital, for example with online games.
• Required audience participation. In the case of sports betting, and live auctions.
• Real-time monitoring. This includes, for instance, search and rescue missions bodiescams of military level, child and pet monitors.
• Remote operation that require consistent connections between remote operators and machinery they control. Example: endoscopy cameras.

What are the best times to utilize low latency streaming

To summarize the various scenarios which we've previously discussed, you need streaming with low latency when streaming either:

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

Why not utilize low latency on all the video content you stream? After all, the lower the time your video content takes being seen by your viewers, the better, isn't it? However, that's not the case. The low latency comes with disadvantages.

The disadvantages include:

• The low latency can compromise video quality. This is because high video quality can slow down transmission workflow due to its large file size.
• It's the only buffered (or loaded) information in the line. There's not much chance of error in the event that there should be a network issue.

When you go live an online streaming service such as rapidly preloads content prior to streaming to viewers. This way, when there's a network problem, plays the content buffered, and allows the slowdown caused by network to be remediated.

Once the network issue is resolved The player will download the top quality possible video. However, all this occurs in the background.

In other words, viewers will enjoy the same high-quality, uninterrupted playback experience unless, in the course of events, a serious incident occurs on the network.

When you select a low latency, however you'll see less replay video the player creates. It leaves little room for error when an issue with your network occurs suddenly.

However, the high level of latency comes handy in certain circumstances. In particular, the longer delay gives the producers time to censor vulgar content or inappropriate language.

Also, in situations where you are unable to compromise on the broadcast quality of your video, raise the delay by a small amount so you can offer a high-quality viewing experience with some space to adjust for errors.

What is the measurement of latency?

In the light of the definition of streaming with low latency and its use cases out of the way, let's see how you can gauge it.

Technically, low latency is measured with a unit called the round-trip time (RTT). It denotes the duration it takes for a data packet to move between points A and B and for a response to be returned to the origin.

To calculate this most effective method is to add time stamps to the video stream and request your teammate to view the live stream.

Ask them to look out for the exact time frame that will appear on their screen. Then add the timestamp's duration from the time the viewer got the exact image. This gives you the latency.

You can also ask a friend to watch your live stream and record a particular cue when it comes. Take note of the moment when you made the cue sound on your live stream, and note the time your designated viewer saw it. This will give you latency albeit not as accurately as the above method. However, it's good enough for a rough idea.

How can you reduce the latency of video?

How do you get lower latency?

The fact of the matter is that there are several variables that affect the latency of video. From encoder settings to streaming protocol you're using, several factors have a role to play.

So let's take a look at these elements and how you can optimize them for reducing streaming delay while also ensuring your quality video doesn't take the biggest hit.

• Internet connection form. The internet connection determines your speed and data transfer rates. This is why Ethernet connections are better for streaming live, compared to wireless and cell data (it's more beneficial to keep those to backup your data, though).

• Bandwidth. A high bandwidth (the amount of data that can be transferred at a time) means less congestion and a faster speed for internet.

• Size of video files. The larger sizes consume greater bandwidth when transferring data from one point to B, which can increase latency and vice versa.

• Distance. It's how far you are from the internet provider. The further you're from the source to your source, the quicker your video stream will transfer.

• Encoder. Pick an encoder which helps maintain low latency when sending signals from your device to the receiving device in as short a duration as you can. However, make sure that the encoder you select will work with the streaming service you use.
• streaming protocol or the protocol that transfers the data you've collected (including audio and video) through your laptop to viewers' screens. For achieving low latency, you'll have to choose the right streaming protocol to minimize the loss of data while also introducing lower latency.

We'll now look over the protocols for streaming that you could select from:

• SRT It is a protocol that effectively sends video of high quality over long distances at low latency. However, since it's relatively new, it's being utilized by various tech companies, such as encoders. How can you solve this problem? Use it in combination with other protocols.

• WebRTC: WebRTC can be used for video conferencing with a bit of compromise in video quality as it's focused on speed mostly. However, the issue is that most players don't work with it due to a complex set up for deployment.
• Low-latency HLS This is ideal to use for latencies that are low, ranging from 1 two seconds. This makes it perfect for live streaming with interactive features. It's an emerging spec so support for implementation is currently in the process.
  

Live stream with low latency

The streaming of low latency is possible with a fast connection to the internet, a good speed, the most efficient streaming protocol as well as an efficient encoder.

Furthermore is that closing the gap between your computer and internet connection and using lower-quality video formats help.