Live streaming has gained popularity over the last few years. With live streaming, viewers can follow important events from the comfort of their own home. For example, viewers can watch live streams of their favorite sports game or race, follow and participate in online auctions, and follow online concerts. Live streaming provides viewers with a feeling of being present at the event itself, which is an important reason for people to follow a live stream. In order to best achieve this feeling, low latency is required.
A high-quality experience can only exist when a live stream is delivering consistent high quality content, without buffering or reloading. If a live stream is not of sufficient quality, most viewers will leave the stream as there is an abundance of choices in other live streams. To organize a good live stream and grow your popularity, you should focus on decreasing latency. There are lots of technologies that can help solve the high latency problem. In this article, you’ll read about how you can deliver the best quality streaming experience.
Understanding Latency in Live Streaming
Latency is another term for delay and usually refers to the delay in telecommunications. For example, when a server sends information to another server, the time that passes between sending and recieving a data package is called the latency. The Internet travels at high speeds so the latency is usually low. If however, there is a disturbance on the line, the latency can be higher, resulting in a bad user experience.
Low latency is very important for live streaming. It can either increase or decrease the user’s experience. If you are live streaming a sports game or other event where time is of the essence and your latency is high, people might already read about important information, such as a goal or results of an election, on the Internet before hearing about it on your live stream. Make sure to use a reliable streaming platform, such as Gcore.com for high-quality streaming.
Video and audio recording
When capturing video and audio for a live stream, the data goes through a long process before it reaches the viewers. The image that you are recording needs to be translated from an analog image to a digital signal. This takes at least 33 milliseconds, no matter what kind of equipment you are using. From a handheld camera to a sophisticated video system, this kind of latency is inevitable. It then needs to be encoded.
Encoding and decoding latency
The digital signal then needs to be compressed to make it suitable for transmission across the internet. This process is called encoding. Encoding is important because an uncompressed file is too big to transmit. Furthermore, a video needs to be encoded to the size of the viewers’ device. Viewers watching on a smartphone require a different size video than those watching on a big screen, such as a laptop or television.
Taking a raw image and compressing it is usually done by software or by using a hardware encoder. If there is little bandwidth available, a file will take a long time to compress. The latency of this process varies from a few milliseconds to 40 to 50 milliseconds. Changing parameters can help to reduce the latency but it will be at the costs of the quality of your video.
Live video encoding is even more complicated. Real-time video and audio needs to be quickly compressed before streaming. It has to greatly reduce the bandwidth it uses but should still maintain a good image quality. This process can cause high latency if the wrong kind of encoder is used. After the data is transported over the internet, it needs to be decoded first before the viewer can see the live stream. It has to go through a software or hardware decoder, which can also contribute to high latency.
Network latency
The data is then transmitted over the internet to a VDS. The encoded media bitrate, internet speed, and bandwidth all have influence on the latency. For example, the internet speed that is available to a viewer greatly influences their latency. The amount of time it takes for data to travel between the server and your viewers’ device is longer if their internet speed is lower.
Before the data can reach a computer, it needs to make many stops and this takes time. Low internet speed only increases this time. Network latency can also occur because of network congestion. This happens when the network is receiving more data than it can handle, and as a result the data gets queued.
Audio latency
Audio latency, also referred to as playback latency, is the time difference between when audio is recorded with a computer system and when it is actually heard. In case of a high audio latency, your audio is not synchronized with your video. People following the live stream will hear the audio later when watching the video. Audio latency can disrupt the recorder’s workflow and frustrate those who listen to the audio.
Player buffering
To ensure a smooth playback of your life stream, the video player it is watched on needs to buffer. Buffers have specific sizes, which are configured in the media specifications. The buffer size is the amount of time it takes for a computer to process the incoming audio or video signal. If a player is set to a high buffer size, the latency will be high as well, where a low buffer size results in a lower latency. Reducing the size costs a lot of computing power so the trick is to find the best balance. By selecting the right format, streamers can improve their video quality and provide a smoother playback.
Impact of latency on viewer experience
Low latency is essential to a good viewer experience. The main reason that it is important is because when watching a live stream, the viewer expects a manner of real-time viewing. If a live stream covers important events but has a long latency, it might happen that certain information is already spoiled by others on the internet. Imagine that the winner of your favorite competition is already announced on Twitter before you hear about it on the live stream. It’s also frustrating to have a live stream that keeps buffering. Internet users are known to have very little patience and will leave the live stream if there is too much latency.
Importance of Low Latency in Live Streaming
Low latency can optimize your viewers’ experience when you’re live-streaming. If you live stream fast and deliver constant quality, chances are that people will like your content and stick with your live stream instead of going to the competition. Having great quality can also stimulate people to recommend your live stream to others, which could greatly increase your popularity. However, if your latency is high, probably the opposite will happen.
High latency has a big negative effect on your viewers’ user experience. If your viewers experience lagging or have to reload your live stream over and over again, they will lose interest and stop watching. Unsatisfied users also don’t interact with bad live streams that experience a lot of latency. Viewer interaction is crucial for growing your profile and becoming more popular, as profiles with a higher user interaction are often recommended to users that don’t follow your account yet. In this way, they will become aware of your live stream and you might gain some new followers.
Popular live streaming content, such as online gaming, sports broadcasting, and remote events, require low latency as high latency could cause viewers to miss important moments. If a goal is made or an important goal in a game is reached and your live stream has high latency, they might already hear it in the neighbourhood or read about it on social media before seeing it on your live stream. Viewers have lots of choices between live streams, so if yours is experiencing high latency, the chance is big they will look for another live stream to watch.
Strategies and Technologies for Achieving Low Latency
Several new technologies for decreasing latency in live streaming have been introduced over the last decades. These technologies all compete with each other, but essentially do the same thing: they split up video content into parts, which are sent to the viewer’s device. With this, they try to enable low latency streaming, while also keeping in mind the scalability. There are ways to optimize latency in live streaming, such as choosing the right video encoder and settings, using a CDN, and implementing adaptive streaming techniques. Furthermore, you can use several emerging open-source protocols, such as WebRTC, Low-Latency HLS (LL-HLS), and Dynamic Adaptive Streaming over HTTP (DASH).
Choose the right video encoder
The first thing you need to do when you want a low latency live stream is choose a good video encoder. Slow video encoders cause lots of latency and have a negative impact on your user experience. The video encoder should be combined with your video streaming solution. There are lots of free video encoders available, or you can use software or hardware. For a high quality stream, you also need to optimize your video encoders’ settings. A higher video resolution is not always the best for your live stream, as it takes a lot of time to transcode. Instead, it is important to find the perfect midway between video quality and speed. Common video resolutions are as follows.
- Standard definition at 720 x 480 pixels (480p)
- High definition at 1920 x 1080 pixels (1080p)
It’s also important to keep in mind your viewers abilities. Their computers might not always be able to handle high resolution video streaming. Your viewers should have a download speed of at least 5 mbps. Higher bandwidth is great, but not all viewers have the internet speed to have high speed, which impacts their streaming resolution and user experience.
A video encoder will usually give you the option to set your resolution to a height of 1080p, 720p, 480p, 360p, or 240p. Always set this to the highest to ensure the best viewing experience without buffering and high latency. The bitcode rate of the encoder determines the rate of data transmission. This setting should be the highest possible, especially if you are transmitting a HD video as it affects the definition.
Use a CDN
CDN’s or Content Delivery Networks are a group of distributed servers that make smooth content delivery possible. They speed up the delivery process, which decreases latency and will ultimately result in a higher viewer experience. When a viewer is trying to watch a live stream, the content will be sent to a CDN near them. Using a server that is geographically closer will make the content delivery faster, because it reaches the viewer quicker than when the server is far away. Using a CDN also improves the resilience of your content, making it less likely for your live stream to go down.
Implement adaptive streaming techniques
Not every computer has the same abilities and screen sizes vary widely as well. In order to make sure that a viewer is watching content in the best quality possible, adaptive bitrate streaming (ABS) should be applied. The ABS sends content in different bit rates through multiple streams. When the user starts to watch the live stream, they will automatically receive the signal with the best quality for their bandwidth and internet connection speed. This ensures that the live stream can be played without buffering and with low latency.
Emerging technologies
Google’s Web Real-Time Communications (WebRTC) is an open-source protocol with conventions, standards, and allows JavaScript programming for end-to-end encryption. It’s fast, widely used, and can pass through firewalls without adding latency or reducing the video quality.
In order to deliver broadcast-quality video streaming over all public networks, Low-Latency HTTP Live Streaming (LL-HLS) was introduced. It is based on Apple’s HTTP HLS protocol. It highly reduces latency, but does prioritize reliability over latency so it’s not always suitable for live streaming over public networks.
Another open-source protocol that can reduce latency is Dynamic Adaptive Streaming over HTTP (DASH). This program can divide live video into segments and decrease their size, before it transports them from web servers to viewers’ devices. The smaller size makes the segments easier to transport and therefore highly decreases latency.
Best Practices for Ensuring Low Latency
There are several things you can do to ensure low latency and that you should surely apply to increase your users’ experience and grow your follower base. Firstly, make sure that you pick a good and quick video encoder and optimize the settings to provide optimal video resolution and speed, preferably using ABS. Make use of CDN’s for transmitting your content from a server nearby your viewer. Also, look into the emerging technologies for delivering high quality video quickly, and pick one that integrates with your live streaming program.
To provide the best experience for your viewers, your own network should be optimized first. For a live stream, you need an upload speed of at least 672 Kbps and a bandwidth of 61.5 Mbps. The resolution, bitrate, and pace of your stream determines how much bandwidth and how much upload speed you really need. If you don’t have enough upload speed, your video might start to buffer. Platforms like Twitch and YouTube even require a certain minimum speed to be able to start a live stream. The processing time of your video can be reduced by using the right video settings and having enough internet upload speed available. Also, make sure that your buffer settings are set to the right size, in order to avoid buffering.
Monitoring and troubleshooting latency issues
Latency issues can be hard to detect. However, there are real-time latency analytics tools that can help you measure your latency and send out a notification when your latency is low. You can also measure latency yourself, by adding a timestamp to your live stream and asking that person to tell you the time stamps as they are watching.
To be sure that you have enough speed to offer low latency, check your internet package to see if it includes the right amount of speed. Also, do a speed test to make sure that your internet is actually delivering the right amount of speed. If possible, use a network cable for a stable and fast internet connection.
CDN’s have data centers called points of presence (PoPs) all over the world. If you want to make sure that your viewers are getting the best experience, you should choose a CDN that has PoPs nearby them. Make sure that your CDN has the option to route around a PoP that is down, in order to keep your live stream up and running.
Conclusion
Live streamers should prioritize and implement low-latency solutions to enhance user experience and engagement. Low latency is crucial for delivering a seamless real-time viewing experience, especially for popular live streaming content like sports events and online gaming. High latency can result in viewers missing important moments and information, leading to frustration and loss of interest.
To achieve low latency, providers can employ strategies such as choosing efficient video encoders, using content delivery networks (CDNs) for faster delivery, and implementing adaptive streaming techniques. Emerging technologies like WebRTC, LL-HLS, and DASH can also help reduce latency. By prioritizing low latency, live streaming providers can attract and retain viewers, increase user interaction, and grow their popularity.