RTMP vs. HLS vs. WebRTC: Comparing the Best Protocols for Live Streaming
Live streaming technology has made leaps and bounds in the past few years. Thanks to these developments, it’s possible for broadcasters with little to no technical knowledge to produce high-quality streams.
One of the most important types of technology that works behind the scenes to deliver video files over the internet in real-time is streaming protocols. While there are many different protocols that work together to bring the streams to life, there are three protocols that are very prominent in the current online streaming scene, including RTMP, HLS, and WebRTC.
In this post, we’re going to compare RTMP, HLS, and WebRTC. We will establish the differences and similarities between RTMP vs HLS vs WebRTC. We will discuss the roles of each of these streaming protocols in live streaming. In particular, we will discuss options for low latency streaming.
Table of Contents
- What is a Streaming Protocol?
- What is RTMP?
- What is HLS?
- What is WebRTC?
- Comparing RTMP vs. HLS vs. WebRTC
- Streaming Protocols on Dacast
- Final Thoughts
What is a Streaming Protocol?
A video streaming protocol is a standardized delivery method that is used to break up a video into chunks, transport it, and reassemble it.
Since video files are notoriously bulky, transporting them requires a highly technical setup. There are many “stops” on a video’s journey from the source to the user-facing video player, and streaming protocols are what bring the video from one stop to the next.
Different protocols are developed by different companies and organizations to serve unique purposes in online video streaming. They are typically standardized and/or open-source so that they can be used seamlessly with different technology and streaming setups.
Some of the most popular streaming protocols include RTMP, HLS, and WebRTC. You will often see these streaming protocols compared against each other, with comparisons such as WebRTC vs HLS and WebRTC vs RTMP commonplace. (paragraph break)
Let’s take a closer look at each of these protocols. This will give you a better understanding of how they work and the purpose that they serve.
What is RTMP?
Real-Time Messaging Protocol (RTMP) is a streaming protocol that was originally used to deliver video content to Adobe’s Flash player. This protocol is known for its capability of low latency streaming.
Since Flash is dead, many people assume that RTMP is also dead, but this is not the case. RTMP has taken a new role in live streaming. It is now used for ingesting media from the encoder or other source to a video streaming platform.
There are many perks of using RTMP for the ingestion of video feeds. For starters, it is currently the most accessible and affordable option since it works with most modern encoders, including many free encoding software. It is also capable of low latency streaming, which is another major benefit for broadcasters.
There are several variations of RTMP that serve slightly different purposes. (change formatting)
- RTMPS, for example, is RTMP with an added layer of security, and it is primarily used for streaming over public networks.
- RTMPE is the variation of RTMP with an added layer of encryption.
- RTMPT is a special variation that is suited for bypassing firewalls.
Unfortunately, RTMP is not compatible with more modern video players, including HTML5, so it is no longer used for delivery in any streaming setups. However, it is very effective in its ingestion role, so it is quite valuable in streaming. As with many types of technology, the role of RTMP continues to change.
What is HLS?
HTTPS Live Streaming (HLS) is a protocol that was developed by Apple for streaming with an HTML5 video player.
To clarify, HLS delivery to the HTML5 video player has replaced RTMP delivery to the Adobe Flash player.
HLS is absolutely essential in most modern streaming setups since the HTML5 video player is the only type of universally compatible video player. Since HTML5 video players come with so many benefits, most broadcasters consider it the only viable option.
Since HLS works with an HTML5 video player, it is capable of streaming to just about any internet-enabled device.
Other than its ultra-compatibility, HLS has several other remarkable perks. HLS is very secure, and it produces high-quality streams.
This protocol also supports adaptive bitrate streaming, which is very important at the professional broadcasting level. In addition to being adaptive, HLS is also dynamic. That means that at any given moment, the bitrate of each individual viewer’s stream will adjust to best suit the connection conditions.
HLS can be used for both delivery and ingest, but it is currently more prominent for delivery since it is not widely compatible with most encoders.
It is also important to point out one major downfall of HLS: when used alone, it causes a latency of 15-30 seconds, which means that the HLS delivery/HLS ingest combination is not capable of streaming with latency as low as some as other setups.
What is WebRTC?
Web Real-Time Communication (WebRTC) is a streaming project that was created to support web conferencing and VoIP. It was purchased by Google and further developed to make peer-to-peer streaming with real-time latency possible.
WebRTC is an open-source project, which makes it possible for developers to use the technology to incorporate streaming in their software.
Although WebRTC is technically a project, it is typically lumped in with protocols since their functionality is very similar.
WebRTC has become very important since the start of the pandemic when streaming with real-time latency has been essential to keeping some semblance of normal throughout many industries. Video conferencing made it possible for many businesses and schools to keep running when in-person meetings were simply not possible.
Currently, WebRTC supports Google Meet, which is a web conferencing tool from Google. It is also used by other popular tools with video conferencing features, such as Slack, Whatsapp, Discord, and Snapchat.
Aside from streaming with real-time latency, WebRTC is very secure. It is encrypted with SRTP and other gold-standard security measures. Like HLS, WebRTC is capable of adaptive bitrate streaming, so you can deliver multiple renditions of your stream with the optimal quality for each viewer.
WebRTC also is known for its customizability and adaptability. It is also capable of streaming to most browsers and types of devices. The combination of these features makes WebRTC a great choice.
Comparing RTMP vs. HLS vs. WebRTC
RTMP, HLS, and WebRTC each have unique roles in live streaming. What they all have in common is that they help transmit data in real-time or as close to real-time as possible. As such, you will often see comparisons of WebRTC vs RTMP or WebRTC vs HLS.
Although you know what each technology does, you’re probably left wondering which is the best for live streaming. The answer? It depends.
Different circumstances call for unique streaming setups and protocols. Currently, HLS delivery with RTMP ingest is the chosen combination in many streaming setups. That is because it ticks the boxes of low latency, ultra-compatibility, and affordability.
HLS delivery can be used with HLS ingest, but there is no widespread support for HLS ingest among encoders and related technology.
When it comes to affordability, it isn’t that the protocols themselves cost more or less. It is the availability and affordability of the equipment that is compatible with each protocol or setup.
WebRTC, on the other hand, is becoming more and more popular. However, it still faces one major limitation: it is not widely supported by most encoders. The same goes for other streaming software, like production and mixing tools.
While this major limitation of WebRTC can be overlooked in peer-to-peer streaming setups that use a digital webcam to capture the video, it poses major issues for broadcasting at the professional level.
Until more encoders and related technology support WebRTC and HLS, the HLS delivery/RTMP ingest combination will likely remain the preferred streaming set up in the professional broadcasting arena.
With WebRTC vs HLS, HLS is more popular for professional broadcasting needs. With WebRTC vs RTMP, it is important to understand that HLS works together with RTMP, so there is no direct WebRTC vs RTMP.
Also, it is worth noting that these protocols are just a few of many available. RTSP and variants of RTMP are also commonly used in streaming. These typically add a slightly different functionality which makes them better suited for different use cases.
Streaming Protocols on Dacast
Dacast strives to provide a professional live streaming experience via an HTML5 video player. Two major goals of the Dacast platform are low-latency streaming and ultra-compatibility.
In order to achieve these two goals, Dacast uses a default configuration of HLS delivery with RTMP ingest.
Dacast also supports an HLS delivery and HLS ingest setup. This streaming setup supports streaming to users on all sorts of devices, but as we discussed before, HLS is not widely compatible with most video encoders. It’s also important to note that this combination is not capable of the low-latency streaming that the HLS delivery/RTMP ingest combination.
Dacast now supports WebRTC streaming as well, giving broadcasters more options to reach their audience. Our team is always working to further develop our software whenever new streaming technology enters the conversation.
Streaming protocols are essential for live streaming over the internet. When you choose a professional video hosting platform, it is important to make sure that your chosen software uses protocols that are compatible with the rest of your streaming setup.
The bottom line is that the HLS delivery/RTMP ingest combination is currently the best way to go. Once supporting technology, like encoders and other software, evolve to support more protocols for ingest, the roles of HLS and WebRTC will shift.
If you are looking for a powerful video hosting platform that is capable of low-latency streaming, Dacast could be a great option for you. Our platform supports live streaming and on-demand video hosting and includes access to tools for video monetization, white-label streaming, an HTML5 video player, cloud transcoding, and more.
We invite you to take advantage of our 14-day risk-free trial. You can access all of our professional streaming features to see how our platform can help you reach your streaming goals.
Sign up today to get started in minutes. No credit card is required.
If you want to learn more about RTMP, HLS, WebRTC, and other streaming protocols, we recommend checking out the Knowledgebase section of our site. A quick search for “streaming protocols,” “RTMP,” or other related keywords will generate documentation that provides more insight on these topics.
For regular live streaming tips and exclusive offers, you can join the Dacast LinkedIn group.