HLS Streaming: All You Need to Know about This Streaming Protocol

If you’ve checked our MKV vs MP4 article, you’ll see that having wide compatibility is a big deal for live streaming. That goes for a streaming protocol as well. And guess what? HLS streaming has become so popular because of that reason, too.

What is HLS streaming? HLS stands for HTTP Live Streaming. It is a protocol for online streaming, supported by many devices and platforms due to HTTP as the underlying protocol. This gives HLS protocol advantages, making it a reliable streaming and content distribution option.

However, broad compatibility is not the only strength of this protocol. So, if you’re curious about the HLS stream and why you should use it, let’s dive right in!

What is HLS Streaming?

HLS is short for HTTP Live Streaming. As its name suggests, it is one of the streaming protocols designed to stream audio and video over HTTP, making it ideal for delivering content over the internet.

HLS protocol itself was developed by Apple in 2009. Before that, Real-Time Messaging Protocol (RTMP) was a hit. People were using it for streaming video content with the Adobe Flash Player plugin installed on the browser and the FLV as the video format.

RTMP and FLV were the go-to standards for web-based streaming video at that time. Unfortunately, Apple then prohibited the use of FLV in their mobile devices.

The reason is the tech company did not support the hassle of installing plugins like Adobe Flash Player, which they considered unstable, less reliable and unsafe for their users.

So, Apple came up with HLS streaming as a solution. They wanted their users to have a more enjoyable and secure streaming experience. And it worked!

More and more devices and platforms started supporting HLS stream, especially after HTML5 video player was introduced and became a trend as media players for websites.

One of the main reasons why HLS streaming has gained major adoption is its advanced features like adaptive streaming. Twitch has become one of platforms that officially support for HLS streaming.

While streamers can upload content using RMTP, the platform will use HLS protocol to provide optimal stream quality for viewers with different download speeds.

With HLS stream, which is not limited to Apple devices, the live stream content becomes way more accessible to bigger audiences. This way, it doesn’t matter what kind of device they’re using, or how good their internet connection is.

But, let’s not forget that even though it’s called livestreaming protocol, HLS is not only for live streaming. In fact, it’s perfect for on-demand streaming, too! Why is that? Let’s learn how HLS streaming works!

How Does HLS Protocol Work?

HLS streaming works by breaking a video stream into smaller segments, and then delivering the chunks over HTTP until reaching the viewers. That way, the audiences can choose the video’s quality levels that suit their network conditions.

Here’s how the HLS protocol works in more detail:

1. Sourcing

As its name suggests, sourcing is the process of getting the raw video content. This happens on the streamers’ or content creators’ side.

The source for live streaming can be anything from a camera feed to any other video content source. You can even use a pre-recorded video file. There are many streaming platforms that allow you to upload a video and make it a live stream.

2. Encoding

The next step in how HTTP Live Stream works is converting the raw video content into a digital format. This process includes compressing the video data, which is known as encoding, to make it all set for streaming over the internet.

Apple themselves officially recommends using the H.264 or H.265 codec. The compression can make the size relatively small, which is great for viewers with slower internet speeds. But, it can still deliver awesome quality.

Thanks to the HLS encoding, your live stream can be more efficient due to the bandwidth saving. It is possible to handle network hiccups better, too.

Read More: Best Live Stream Encoders

3.Segmenting

This is an important step in making HLS videos accessible through live streams. Segmenting is about dividing a video file into tiny blocks which are typically less than 10 seconds long.

Breaking the video into small segments makes it possible for online streaming. Not only that, this allows you to have adaptive bitrate, too. It means the video can be consumed based on the viewers’ network quality.

Don’t worry, if the viewers want to lock in at a certain video quality to ensure a smooth experience, they can do that as well.

4. Creating Playlist

Not only segmenting an HLS video, but the process will also involve creating an index file, which will act as a playlist. Basically, this HLS file keeps track of the segments and their play order.

This process works for both live content and pre-recorded content. Technically, the steps are the same, but there’s a slight difference.

In on-demand content, the playlist is static. But in a live stream, it is so dynamic that the HLS protocol will always create new playlists that need to be updated on the viewers’ side as the stream goes.

Don’t forget that there will be separate playlists for each bitrate, too.

5. Distributing through Server

The next step in the HLS streaming process is getting those segments and playlists up on a web server. That way, the clients can access them using the HTTP protocol.

When it comes to the server, you can go with a standard web server, or consider using a Content Delivery Network (CDN). The latter will give you better performance.

CDN has servers scattered worldwide so your viewers will be served from the closest server to their locations. This will make them access the content faster and easier.

6. Serving the Clients

This last step will happen on your audience’s side. Basically, the viewers can simply use their web browsers or mobile apps to request the playlist from the server. The type of content they’re enjoying will determine whether it’s a static or dynamic request.

They can use the default bitrate for playing HLS media which will be dynamically adjusted or manually choose a specific streaming quality, let’s say 480p.

Now, you know how HLS streaming works. But, why do you need to use this protocol?

Why Use HLS Stream?

Here is the reason why you should use the HLS stream:

1. Wide Compatibility

As mentioned earlier, if you want to ensure your livestream is compatible with different platforms, the HLS protocol is the way to go. It’s supported by Android, iOS, Windows, Linux, and more, even though Apple created it.

What’s more, the underlying HTTP protocol works on all online devices. Also, the H.264 video codec and AAC audio codec used in HLS are widely supported. This makes it super easy to start streaming on any platform with an HLS protocol.

With the combination of HTML5 video prayers, streaming on any modern browsers using HLS will guarantee an awesome experience, too.

2. Simple HTTP-Based Delivery

HLS has the advantage of using a simple HTTP-based delivery, which offers several benefits.

Firstly, you can start using a single web server for simple live streaming. To reach more viewers, you can scale up by utilizing a CDN.

Secondly, the HTTP protocol is commonly permitted through firewalls and proxies. This means your viewers can access HTTP Live streams even in environments with customized network configurations, such as public Wi-Fi hotspots. This is a significant improvement compared to the issues often encountered with RMTP or RSTP.

Lastly, using caching to store frequently accessed content can reduce bandwidth. This especially applies to HLS streams that are using CDN servers.

3. Embedded Closed Captioning

If you really want to take your channel to the next level, reaching a bigger audience is vital. To make that happen, you need to make sure your content is accessible to everyone. One way to do that is by using closed captions, which are text versions of your videos’ audio.

Luckily, HLS streaming provides native support for embedded closed captions. So, you can take advantage of this feature which will not only help viewers who are hard of hearing, but it’s also useful for those watching in noisy environments or with the sound turned off.

What’s more, having this function means your live stream will meet the legal requirements in many places, which often require the inclusion of captions.

3. Multi-Purpose

HLS streaming is awesome for both live stream and on-demand content. So, you can think of it as a versatile protocol.

We have explained above how it works. Simply put, when it comes to streaming live with HLS protocol, the video will be captured, encoded, and segmented in real-time, and included in the new segments. The audiences then download the HLS file periodically and play those segments sequentially.

The same thing goes for on-demand content. However, the whole content will be available before streaming begins. That’s why viewers can control their viewing experience. They can pause, rewind, fast-forward, and resume the video using the adaptive bitrate streaming of HLS.

4. Adaptive Bitrate Functionality

The ability to adjust the quality of a video stream that suits network conditions and the device’s capabilities makes HLS streaming awesome.

This adaptive bitrate will start with a lower bitrate so the video can play quickly. If the network conditions are excellent, it will request a higher bitrate stream, resulting in better video quality.

5. Suitable for All Network Types

Aligned with the adaptive bitrate functionality, HLS streaming is an all-around protocol that works well on various types of networks. That’s why you can cater to audiences with both high-speed broadband connections and slower mobile networks.

While maintaining acceptable video quality is crucial, you should never forget that a smooth streaming experience is paramount.

Let’s say your audience starts watching a live stream using their Wi-Fi network at home. They will be served a high-bitrate stream. When they leave their home and switch to a mobile network, they will switch to a lower-bitrate stream to avoid buffering.

6. Support DRM for Security

Imagine you’re streaming exclusive content to your audience, only to discover that someone can access it without permission. How would you feel?

That’s why protecting your video content is so important. This applies to live stream and on-demand video content.

HLS streaming supports Digital Rights Management, or DRM, which safeguards your digital content. It helps prevent unauthorized redistribution and ensures copyright protection.

By using the HLS protocol and implementing DRM, you can effectively protect your video content from piracy and unauthorized access.

When to Use HTTP Live Streaming?

With all those reasons above, you should use HTTP Live Streaming for your online streams whenever these things apply:

1. Your Audience is from Around the World

Do you want a global audience that’s totally into your content? If so, then HLS streaming is an ideal option. This protocol works great on any type of network, so viewers with slower internet can still enjoy your stream with decent quality.

On top of that, you should use HLS protocol with built-in close captioning to make more audience enjoy your content in any situation.

2. You Want a Multi-Platform Live Stream

If most of your audience is using Apple devices, then you must go with the HLS protocol. It works like a charm and makes a seamless streaming experience possible with top-notch performance.

But, you should not think it’s limited to Apple alone. HLS is a universal protocol that works great with tons of devices, browsers and operating systems, like Android and Windows. So, if you’re a content creator aiming for the widest audience possible, HLS streaming should be your pick.

3. You are Targeting Mobile Users

Keep in mind that HLS streaming came onto the scene just a few months after the iPhone 3 hit the market. It was all about making video content more enjoyable on mobile devices from the first time.

Fast forward to today, there are over 58% of mobile users around the world, leaping ahead of desktop users. So, it will be a big loss if your live stream targets those mobile viewers specifically, but you don’t use HLS streaming.

4. You Want to Use HTML5 Player

HTML5 has become the new standard for embedding and playing video content on most browsers. Unlike the old Flash player, you don’t need extra plug-ins to watch videos. It even supports adaptive streaming, too.

What makes it more interesting is HLS streaming and HTML5 players go hand in hand. They work together seamlessly, making it an awesome choice for content creators and streaming platforms to provide the best streaming experience for the audience.

So, if you want to make the most of the versatility of HTML5 and the HLS protocol, kickstart your livestream with the HLS protocol.

5. You Wish to Secure Content with DRM

DRM is vital for streamers relying on revenue from their digital content. And thanks to HLS’s built-in support for DRM, you can use various encryption methods to ensure that only eligible viewers can enjoy your exclusive content.

But there’s more, HLS supports multiple DRM systems, such as FairPlay Streaming by Apple, Adobe Primetime, Google Widevine, and Microsoft PlayReady. With these options, you can pick the best DRM system for you and your audience.

With DRM in place, sports broadcasters can make sure only paying subscribers get access to their live streams. And for on-demand content, you can keep out of the unauthorized distribution of your gameplay streams.

Not only that, you can even monetize your content in different ways. Do you think about subscriptions, pay-per-view, and more? It’s all up to you.

6. You Want to Meet Certain Standards

If you are a professional streamer wanting to reach a bigger audience, including TV viewers, you must pay attention to the CEA-708 regulations. Then, make sure that your content complies with this standard.

Basically, CEA-708 requires you to have a close caption embedded into your video.

As HLS streaming totally supports this standard, you need not worry. You can rest assured that your content will meet the accessibility requirements set by the regulation. Some platforms even have automatic closed caption detection to make things easier.

7. You Don’t Mind with the Delay

HLS was not designed with ultra-low latency in mind. Its main goal was to ensure you can access the content easily on many different devices. No wonder many people complain about the delay when using HLS streaming.

While this does not impact the video quality, this surely correlates with viewers’ experience as it can delay up to 30 seconds. Especially for interactive live streams, this delay can disrupt engagement.

Apple themselves has updated the protocol with HTTP Live Streaming 2nd Edition, with these improvements:

• Generation of partial segments
• Playlist delta updates
• Blocking of playlist reload
• Using preload hints
• Rendition reports

It’s a major upgrade that brings some serious improvements but comes at a cost. Not all Android devices are compatible with this new low-latency HLS streaming.

HLS Alternatives

HTTP Live streaming protocol is a protocol that comes with a lot of perks. However, there are HLS protocols alternatives that you might want to check:

• RTSP (Real Time Streaming Protocol) — a protocol for streaming media over IP networks which is specifically designed to control media sessions
• RTMP (Real-Time Messaging Protocol) — a popular protocol for streaming live video with relatively low latency. It was the default protocol for Flash Player
• Smooth Streaming — an extension of IIS Media Services of Microsoft that can provide up to 1080p video quality streaming
• HDS (HTTP Dynamic Streaming) — another technology developed by Adobe for streaming without the need to install Flash player and support innate content protection
• WebRTC (Web Real-Time Communication) — an open source protocol that makes audio and video communication inside web pages possible, can be used for live streaming
• MPEG-DASH (Dynamic Adaptive Streaming over HTTP) — an open standard adaptive bitrate streaming technology using HTTP protocol to ensure efficient bandwidth and awesome video quality
• SRT (Secure Reliable Transport) — a protocol that focuses on low latency streaming, making it ideal for any remote live streams
• CMAF (Common Media Application Format) — a unique protocol that focuses on simplifying the delivery of HTTP-based streaming media to make it cost-effective
• RIST (Reliable Internet Stream Transport) — an open standard protocol based on ODP with a focus on low latency, availability, and security

Here is the table to compare those HLS streaming alternatives:

Protocol	Released by	License	Latency	Browser Support	DRM Support	Used for
RTSP	IETF	Free	Low	Need plugins	Yes	Internet radio
RTMP	Adobe	Proprietary	Low	Need Flash Player	Yes	Live Streaming and VOD
Smooth Streaming	Microsoft	Proprietary	Medium	Silverlight	Yes	Live Streaming and VOD
HDS	Adobe	Proprietary	Medium	Need Flash Player	Yes	Live Streaming and VOD
WebRTC	Google/W3C/IETF	BSD	Low	Most modern browsers	Yes	Live Streaming
MPEG-DASH	MPEG	Free	Medium to High	Most modern browsers	Yes	Live Streaming and VOD
SRT	Haivision	Open Source	Low	No native browser support	No	Video Delivery
CMAF	MPEG	Free	Low	Modern browsers with Media Source Extensions	Yes	Simplify the streaming process
RIST	VSF	Free	Low	No native browser support	Yes	Video Delivery

Conclusion

HLS or HTTP Live Streaming is a game-changing protocol that reshapes the streaming experience for content creators and viewers.

The HLS protocol breaks down a video into smaller chunks to prepare it for online live streaming. With this protocol, you can reach a broader audience for your content without worrying about low quality. Yes, its adaptive bitrate feature promises an uninterrupted streaming experience for any network conditions.

For streamers who wish to monetize their content, this protocol can be a great pick because of its full support for DRM. This means you can easily protect your content, whether it’s for live streams or on-demand videos.

That’s all for now! We hope this article has given you a complete overview of the HLS stream.

FAQ on HLS Streaming