An introduction to

A lot of us are aware of the delay when it comes to video data transmission.

So what exactly is low latency? Do you need to reduce latency on all of your live event? Let's answer all this and more with this article.

A primer on low latency

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

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

It is a good thing that not every live event demands the use of low latency.

You need it when you live stream events to provide a live interaction or viewing experience. When you live stream, your audience expects to be able to watch and/or be a part of the action as the event unfolds. Therefore, you cannot afford to pay for excessive latency, and have to stream with lower than 4K video resolutions.

This is low latency streaming in a nutshell, let's dig deep into the particulars of how and how.

What exactly is low latency?

When translated, latency literally is a term that means "a delay in the transfer.'

For the purposes of video latency, this means the length of amount of time that it takes for the moment you capture your video on your camera to play within your viewers' player.

Thus, low latency means lower time spent in moving video content to point A (your headquarters for streaming) and to the point of B (your audience's players).

Similar to that, a higher latency means more time in video data transfer from the live streamer to their audience.

What is considered as a low latency?

Based on industry standards, low latency live streaming video has a duration of 10 seconds or less while broadcast television streaming is between 2 and six minutes. In the case of your particular use you may even attain ultra-low latency which lies between 2 - 0.2 seconds.

Why do you require low latency in video streaming? There is no need for the same level of latency for each 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 then you'll require a the lowest latency to stream your event. Why? to ensure that all interactions are displayed on time - and without the possibility of delays, which could give some participants an unfair advantage.

We'll look into more of these scenarios later.

When do you need streaming that is low-latency?

The greater participation in live streaming your event needs and the more duration you require. This way, attendees can live-stream the experience without any delay.

These are some instances where it is necessary to stream at a low-latency:

• Two-way communicationsuch as live chat. This includes live events where Q&As are involved.
• Real-time viewing experienceis essential such as with online games.
• Required audience participation. For instance, in cases of casinos online, gambling on sports and auctions that live.
• Real-time monitoring. For example, search and rescue missions bodiescams of military level, baby and pet monitors.
• Remote operations that require consistent connection between distant operators and machinery that they are in control of. Example: endoscopy cameras.

When should you use low latency streaming

To summarize the various scenarios we explored above It is necessary to have low latency streaming when you're streaming any of the following:

• Time-sensitive content
• Content that needs an immediate interaction with the audience and engages them

But why not use low latency for all the video content you stream? After all, the lower the delay in your content reaching your viewers the better, isn't it? But, it's not so simple. Low latency does comes with drawbacks.

These drawbacks are:

• The low latency can compromise the quality of video. The reason: high video quality slows the process of transmission due to the huge volume of files.
• There's not much buffered (or loaded) content in the line. There's not much room for error should there an issue with the network.

In the event of live streaming an online streaming service such as swiftly pre-loads some of the content prior to streaming to viewers. In this way, if there's an issue with the network, it plays the buffered video, which allows the slowdown caused by network to be remediated.

When the problem with the network is fixed The player will download the top quality possible video. This, however, takes place in the background.

The result is that viewers receive an uninterrupted, high-quality replay experience, unless obviously, a significant network mishap occurs.

When you opt for low latency, however it's not as much playback video to be prepared by the player. There's a little room for error when a network issue strikes out of the blue.

That said, high latency is useful in some situations. As an example, the greater time-lag allows producers chance to remove insensitive content as well as profane.

Similarly, in cases where you can't compromise with the quality of video broadcasting, you can increase the speed of transmission to ensure an excellent viewing experience, as well as allow to adjust for errors.

How is latency measured

With the definition of low latency streaming and its applications in the past Let's look at how you measure it.

The technical term for low latency refers to the time measured with a unit called the round-trip time (RTT). It denotes the time it takes a data packet to move from point A to point B and for a response to reach back the source.

To calculate this most effective method is to use video timestamps and ask a teammate to watch the live stream.

Have them look for the exact time frame that will appear on the screen. Next, subtract the timestamp's time from the moment the user was able to see the exact frame. That will calculate your latency.

Alternatively, ask a teammate to follow your stream, and take a signal when it appears. Now take the time when you made the cue sound on the live stream and when your assigned viewer saw the cue. This will give you time, although not as precise like the previous method. It's still enough to give you a rough estimate.

How to reduce video latency

Now how do you achieve lower 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 in.

Let's take a take a look at these elements and the best way to maximize the way you use them to decrease latency , while ensuring that the quality of your videos don't suffer an enormous hit.

• Internet connection form. The internet connection affects data transmission rates and speed. It's why ethernet connections are better for streaming live, compared to wireless and cell data (it's recommended to use them to backup your data, though).

• Bandwidth. A high bandwidth (the amount of data which can be transferred at a moment) is less crowded and more speedy internet.

• Video file size. Bigger sizes require more bandwidth in transferring between points A and B, which increases time to transfer and vice versa.

• Distance. This tells you how far you are from your Internet source. The closer you are to your source, the quicker the stream of video will move.

• Encoder. Pick an encoder which helps you keep low latency by transmitting signals directly from your device to the receiving device as quickly a period of time as is possible. However, make sure that the encoder you select works with your streaming service.
• Streaming protocol or the protocol used to transfer your data packets (including video and audio) through your laptop to viewers' screens. In order to achieve low latency you'll need to select an option that minimizes data loss and introduces less latency.

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

• SRT It is a protocol that effectively transmits high-quality video over lengthy distances while maintaining minimal latency. However, since it's relatively new, it's still being utilized by various tech companies, such as encoders. What's the solution? Combine it with an alternative protocol.

• WebRTC: WebRTC can be used for video conferencing however it has a few compromises in video quality as it is focused on speed, primarily. The problem, however, is that the majority of players don't work with it due to a complex set up to deploy.
• HDL with low-latency is great for low latencies of up two seconds. This makes it perfect for live streaming with interactive features. But, it's still an emerging spec so implementation support is in the development.
  

Live stream, with low latency.

A low-latency stream is feasible with a speedy internet connection, a high capacity, best-fit streaming protocol as well as an efficient encoder.

What's more, closing the distance between you and your internet connection as well as using smaller videos can be helpful.