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The Complete Guide to Live Streaming

Published on April 4, 2022
The Complete Guide to Live Streaming

In the last half-decade, streaming has become more than just a convenient and innovative technology; it has become an economy of its own. The advent of streaming video has completely changed the landscape of how people view and share information. And it's not just entertainment that is being streamed; live events, such as political debates or award shows, are now being seen by more people than ever before.

Thanks to streamers' ability to connect with their audience in real-time, platforms like Twitch have also exploded in popularity, allowing people to create scalable content from their bedrooms.

As streaming becomes more popular, it's essential to understand the technology that makes it possible. In this blog post, we will discuss how live streaming works and some of the key components involved.

What is live streaming?

Streaming is a form of data transmission that allows users to watch content as it is being transmitted. This differs from traditional methods of viewing media, such as downloading whole video files to watch. It is a way to deliver a video file in a concise amount of time without requiring the entire file to be downloaded first.

Live streaming is a method of broadcasting video in real-time over the internet. It is a form of data transmission that allows users to watch content as it is being transmitted instead of downloading or waiting for the entire file to be downloaded first. It is different from other forms of streaming because it does not require that a video be recorded or stored.

In simpler terms, you can think of live streaming as a way of watching TV or a movie in real-time over the internet. Instead of waiting for the show to air on your local TV station, you can watch it as it's happening live, from anywhere in the world. Instead of an actor reciting a script or monologue, live streaming is more like improvising a speech or conversation in front of a live audience.

How does live streaming work?

Live streaming requires three basic components: the encoder, the server, and the player. The encoder is responsible for converting video into a format streamed over the internet. The server is what distributes the content to viewers around the world. And the player is the software that viewers use to watch the stream.

When someone wants to live stream a video, they first need to install an encoder on their computer. This software will take the video input and encode it into a format streamed over the internet. The encoded video is then uploaded to a server stored for later viewing. Viewers who want to watch the live stream will need a player, which is just another piece of software that allows them to view the video as it's being streamed from the server.

The encoding process can be done in real-time with some encoders and servers, but this requires breakneck internet speeds and expensive hardware. Most live streamers prefer to use a delayed encoder and server, which requires less hardware but takes longer to upload the video.

The steps are as follows:

Capturing live content

The first step in live streaming is capturing audio or visual content using an encoder. The encoder may be a dedicated piece of hardware that has been designed specifically for this purpose, or it could also be software that runs on a computer.

Compression and encoding

The content is then compressed and encoded into a format streamed over the internet. This step is necessary because live streaming requires much higher bandwidth than traditional methods of video transmission, such as downloading or streaming from a CDN.

Streaming over the web involves two types of servers: the origin and distribution servers. The origin server is responsible for storing live video feeds in their entirety; it is also where transcoding happens. Transcoding refers to the process of converting digital files from one format into another (e.g., converting a video file into an audio file). This can be done with specialized software or through hardware encoding devices like the H.264 encoder, which converts files to QuickTime Media Format (QTM) using Apple's proprietary codecs such as AVC and H-264 video compression and AAC for audio compression.

Segmentation

The compressed and encoded content is then segmented into small packets transmitted over the internet to a streaming server. This is done by creating a streaming media file, a special video file that can be played back by a streaming player. Unlike small files (like photos and PDFs), video files are large and can take a long time to download on their own. Segmentation is a necessary step to take before transmission because it allows video files to be downloaded much more quickly.

Content Delivery Network distribution

Once the files have been compressed, encoded, and segmented (which happens in less than a few seconds), it needs to be distributed to millions of people to view. To do this in a low-latency way, the streaming server then transmits the video to a content delivery network (CDN).

A CDN is a system of servers located around the world and can quickly distribute large amounts of data. This is advantageous to the host because it dramatically reduces the origin server's workload. The CDN will transmit the video to viewers worldwide who watch it using their computers or other devices connected to the internet.

CDN caching

One of the benefits of using a CDN for live streaming is that it can cache the video content. This means that the CDN will store a copy of the video on its servers, allowing viewers to watch the video even if the original streaming server is unavailable. CDN caching also allows the CDN to deliver the video more quickly since it doesn't need to download the entire file from the streaming server before sending it to viewers.

Decoding and playback

Finally, the content is decoded and played back for viewers using a media player. Decoding is done by the media player, a piece of software that can play video and audio files back.

Why do you need a CDN for live streaming?

CDNs are powerful tools, and live streaming is among their most advanced features. Among the numerous reasons to use a CDN for live streaming, these ones make it a necessity:

Speed and reliability

A CDN can be used for live streaming because it's fast and reliable. A CDN will transmit the video to viewers worldwide who watch it using their computers or other devices connected to the internet. This is valuable to hosts because it dramatically reduces their workload by offloading content delivery from origin servers onto a network of distributed servers.

Redundancy

CDNs also have built-in redundancy, which means that if one server goes down, another will take its place without interruption in service. CDN caching is another benefit for hosts because it allows viewers to watch videos even when the original streaming server is unavailable by storing copies of video content on CDN servers around the world so they can be streamed quickly and without interruption.

Global reach

CDNs also have a global reach, which allows them to deliver video content faster and more reliably than traditional hosting solutions. When using a CDN for live streaming, you can be sure that your content will be delivered to viewers no matter where they are in the world.

Latency and RTT reduction

Latency and round-trip time (RTT) are two of the most significant issues that affect live streaming. By using a CDN, you can dramatically reduce both latency and RTT, making for a smoother viewing experience for your viewers.

Cost-effective

Finally, CDNs are cost-effective because they allow hosts to offload the streaming process and content delivery onto a network of distributed servers. This reduces costs by minimizing server maintenance tasks such as scaling up resources when demand increases or upgrading hardware over time as technology advances become obsolete at an alarming rate (not all applications will need this type of service).

HTTP live streaming

An increasingly popular method of live streaming is called HLS (or Apple's proprietary "Apple Streaming Protocol"). This protocol was created by Apple and works with devices that can play media files over an internet connection.

HLS has become the most common standard for delivering audio and video because it uses a playlist file to deliver content in smaller chunks called "segments," which are typically around six seconds long.

Viewers on demand then download the segments, so they don't have to wait for a full download before watching the video. HLS is based on what is known as "adaptive bitrate streaming" because it adapts the quality of streamed content to match each viewer's device capabilities and network conditions.

This ensures a smooth viewing experience for all viewers, regardless of their device or internet connection speed. In addition, HLS is backward compatible with older devices and browsers that don't support HTML video tags.

How to use the HLS protocol

To deliver live content using the HLS protocol, you'll need an encoder to create an HLS playlist file. Some encoders are software-based, while others require hardware to encode the stream into an HLS playlist file. In addition, you'll need a server that can host your HLS content and deliver it through the internet or over public networks like mobile networks (e.g., cellular data).

Several servers are available on the market that can host and deliver HLS content, including Wowza Streaming Engine, Adobe Media Server, and Microsoft Azure Media Services. These servers typically require a subscription or usage fees in order to use their services.

Benefits to HLS

There are several benefits to using the HLS protocol for live streaming. These benefits include:

  • Increased compatibility with devices and browsers
  • Smooth viewing experience for all viewers, regardless of device or internet connection speed
  • Backward compatibility with older devices and browsers
  • Ability to stream content over both public and private networks
  • Use of a playlist file to deliver content in smaller chunks

MPEG-DASH

Another popular method for live streaming is called MPEG-DASH (or "Dynamic Adaptive Streaming over HTTP"). This protocol was created by the Motion Picture Experts Group and works with devices that can play media files over an internet connection.

MPEG-DASH has become a common standard for delivering audio and video because it uses a playlist file to deliver content in smaller chunks called "segments," which are typically around six seconds long. Viewers on demand then download the segments, so they don't have to wait for a full download before watching the video.

MPEG-DASH is also based on what is known as "adaptive bitrate streaming" because it adapts the quality of streamed content to match each viewer's device capabilities and network conditions. This ensures a smooth viewing experience for all viewers, regardless of their device or internet connection speed.

How to use MPEG-DASH

Live streaming with MPEG-DASH works similarly. You'll need an encoder to create a MPEG-DASH playlist file and a server to host your stream. Like we said earlier, some of the popular servers for hosting streaming content include Wowza Streaming Engine, Adobe Media Server, and Microsoft Azure Media Services. These servers typically require a subscription or usage fees in order to use their services.

Benefits to MPEG-DASH streaming

The benefits of live streaming with MPEG-DASH are similar to those for HLS. These include:

  • MPEG-DASH is typically used for delivering audio and video over the internet or public networks like mobile (i.e., cellular) data networks
  • It is seen as the standard for adaptive bitrate streaming
  • Adapts the quality of streamed content to match each viewer's device capabilities and network conditions
  • Backward compatibility with older devices and browsers

However, one key drawback to MPEG-DASH is that it is not supported on Apple devices, including iPhones and iPads. In addition, it is not supported by Safari, the default browser on Apple devices.

Does KeyCDN support live streaming?

Yes, KeyCDN supports live streaming content. You can use HLS or MPEG-DASH to deliver your content and set up a pull zone in the KeyCDN dashboard. Once you've done that, you'll simply need to enter the URL of your stream into your video player (e.g., JW Player or Video.js), and you're ready to go.

To sum up, there are several methods for live streaming content on the web. The most popular methods are HLS and MPEG-DASH, which both have their own benefits. KeyCDN supports both of these methods, so you can choose whichever is best for your needs.

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