BroadCam Video Streaming and Broadcasting Software
When you get started with live streaming, you’ll notice an abundance of acronyms that serve many different purposes. There’s RTMP, HLS, SRT, and more.
Many of these acronyms relate to different video streaming protocols. Basically, protocols are technical processes that facilitate the transfer of data from one program to another. In streaming, this means the transfer of your video files to and from your encoder, streaming host, and eventually, the video player where your audience views your stream.
Today, we’re going to identify some of the most common video streaming protocols you’ll encounter, what they do, and when they should use them. We will break down all the acronyms associated with different video streaming protocols. In order to provide some relevant background to help you understand, we’ll also explain the relationship between a codec vs a container format.
Are you ready to dive into live streaming protocols?
What is a Video Streaming Protocol?
A video streaming protocol is necessary for live broadcasting.
A video streaming protocol is a standardized delivery method for breaking up a video into chunks, sending it to the viewer, and reassembling it. Video streaming protocols are the rules and methods that are used to break video files into small pieces so that they can be delivered to your viewers.
Before we go further, let’s look a little further into the “why” behind video streaming protocols. Most digital video is designed for two things: storage and playback. This leads to two major considerations, namely small file size and universal playback.
Most video files aren’t designed for streaming, which means streaming a video involves first converting it into a streamable file. This involves breaking the video up into small chunks. These chunks then arrive sequentially and playback as they’re received. If you’re streaming live video, the source video comes in straight from a camera. Otherwise, it’s coming from a file for video-on-demand VOD content.
That is a basic explanation of how streaming protocols work. Streaming protocols can get much more complex. Many are “adaptive bitrate” protocols, for example. This technology will deliver the best quality that a viewer can support at any given time.
So if a viewer has a slow internet speed, they will be delivered a lower-quality video, and if a viewer has a faster internet speed, they will be delivered a higher-quality video.
Some protocols focus on reducing latency, or the delay between an event happening in real life and when it plays on the viewer’s screen. Some video protocols only work on certain systems, and other video protocols focus on digital rights management (DRM).
As we move through some specific video streaming protocols, we will put these and other characteristics into perspective.
6 Preferred Protocols for Video Streaming
Now that you have a better idea of the purpose of video streaming protocols, let’s start our comparison with a list of the most common protocols for video streaming today. This will help you better understand the best video protocols for live streaming and videos-on-demand.
In this comparison, we’ll also offer use cases for each video protocol whenever possible.
1. HTTP Live Streaming (HLS)
The HLS protocol, or HTTP Live Streaming, was developed by Apple and has support for media players, web browsers, mobile devices, and media servers.
The first video streaming protocol we’ll discuss is HTTP Live Streaming or HLS. Apple originally released this video protocol in 2009 to enable them to drop Flash from iPhones. Since then, HLS has become the most widely-used streaming protocol.
There are several reasons for this. First, desktop browsers, smart TVs, and both Android and iOS mobile devices all support HLS. HTML5 video players also natively support HLS streaming. With so many devices supporting HLS, it is only natural that it has become one of the best video protocols for streaming video.
This allows a stream to reach as many viewers as possible, making HLS the safest protocol today for scaling a live stream to large audiences. For example, you can use this protocol to stream live video on your website with a simple embed code, and you can reach viewers on most devices.
As far as features, the HLS standard also supports adaptive-bitrate streaming, dynamically delivering the best possible video quality at any moment to each individual viewer. With recent updates, this standard now supports the latest and greatest H.265 codec, which delivers twice the video quality at the same file size as H.264.
Currently, the only downside of HLS is that latency can be relatively high. Latency is the delay one experiences between when a file is sent and the viewer receives it. With live video streaming, latency can best be described as the delay between when live content and when the viewer gets that content. However, there are methods for reducing HLS latency, helping to combat one of the few downsides to this video protocol.
Who Should Use HLS?
HLS is the most widely-used protocol for live stream delivery because it’s robust and effective. For example, we know that few viewers will return to a site during a stream if they experience a video failure. Using a widely compatible, adaptive protocol like HLS will deliver the best possible audience experience. HLS is one of the best protocols for streaming video.
We’d also like to mention that HLS is now the default streaming protocol at Mslive.
Pros of Using HLS:
- Highly compatible: Since HLS is compatible with the HTML5 video player, the HLS protocol is suitable for streaming to practically any internet-enabled device and operating system
- Secure: HLS is known for secure streaming
- High quality: HLS produces ultra-high-quality video streams thanks to its adaptive bitrate streaming technology
Cons of Using HLS:
- High latency: HLS is not capable of latency as low as some of the other preferred protocols
- Not great for ingest: HLS isn’t the best option for ingest since HLS-compatible encoders are not accessible or affordable
2. Real-Time Messaging Protocol (RTMP)
Next up is the veteran video protocol: RTMP or Real-Time Messaging Protocol. Originally developed by Macromedia in the early days of streaming, the RTMP protocol is still widely used.
Today RTMP is mostly used for ingesting live streams with the help of an RTMP-enabled encoder. In plain terms, when you set up your encoder to send your video feed to your streaming platform, that video will reach the platform via the RTMP protocol. That content eventually reaches the end viewer in another protocol, usually HLS. RTMP is used together with other video streaming protocols.
RTMP is rarely used as a viewer-facing video streaming protocol like it once was. That’s because it’s dependent on the Flash plugin, which is now totally obsolete. If it is used, it is usually paired with another protocol like HLS.
Who Should Use RTMP?
RTMP is a streaming protocol that provides very low latency streams. However, because it is incompatible with the HTML5 video player, we do not recommend using RTMP for delivery. Again, the exception is for stream ingestion. For this purpose, RTMP ingest is still one of the best options for stream ingestion. It’s robust and almost universally supported.
Pros of using RTMP:
- Low latency: Low latency allows your live video stream to maintain a stable connection and video feed for the viewer, even if the internet connection is unreliable. This provides your viewers with fewer “lags” when watching your videos with a shaky internet connection, allowing them to quickly resume the stream once their internet connection stabilizes.
- Adaptable: An adaptable feed means your viewers aren’t locked into watching your feeds in one linear direction. With content hosted on an RTMP server, the feed allows them to skip and rewind parts of the feed or to join a live stream after it’s begun. Viewers often expect this type of control over the content they watch.
- Flexible: RTMP allows you to integrate a variety of video formats into one cohesive package, seamlessly blending audio, video, and text. Additionally, you can have multiple variations of media channels, such as streaming both MP3 and AAC audio streams or streaming MP4, FLV, and F4V videos.
Cons of Using RTMP:
- Not supported by HTML5: RTMP is supported by Flash players, a format that’s well on its way toward obsolescence. HTML5 players are quickly becoming the modern standard, but RTMP cannot play on HTML5 players without a converter such as HLS video protocol.
- Bandwidth issues: RTMP streams can be especially vulnerable to issues of low bandwidth. This can cause frequent, frustrating interruptions to your streams that ruin the experience for your viewers.
- HTTP incompatible: You cannot directly stream an RTMP feed over an HTTP connection. To use an RTMP stream on your website, you have to connect to a special server, such as the Flash Media Server, and use a third-party content delivery network (CDN).
3. WebRTC
WebRTC is primarily used for peer-to-peer communication, specifically with web conferencing.
Web Real-Time Communications (WebRTC) is an open-source video project that is capable of streaming with real-time latency. This project was developed to support voice-over-internet protocol (VoIP), and it was purchased by Google to support Google’s video chatting tools.
WebRTC is technically a streaming project and not a streaming protocol. However, it is often lumped in with the preferred video streaming protocols since there is a lot of overlap.
Who Should Use WebRTC?
WebRTC is valuable in streaming setups that require real-time latency. Peer-to-peer streaming, which is commonly called “web conferencing” or “video conferencing” is one of the top use cases of WebRTC.
Some popular software and apps that use WebRTC include Snapchat, Facebook, WhatsApp, and other social media platforms that support video chatting.
Pros of Using WebRTC:
- Open-source: Since WebRTC is open-source, it can be customized to suit your specific streaming needs
- Real-time latency: WebRTC supports streaming with real-time latency, which means that your video travels to your viewers’ screens in virtually real-time
Cons of Using WebRTC:
- A Newer Tech: WebRTC is a recent development and so the rest of the market hasn’t adapted yet. You may find some issues with streaming setup compatibility
4. Secure Reliable Transport (SRT)
Secure Reliable Transport (SRT) is a relatively new video streaming protocol from Haivision, a leader in the online streaming industry. This open-source protocol is known for its remarkable security, reliability, compatibility, and capability of low latency streaming. It is a great real-time streaming protocol.
There are currently some limitations on streaming with SRT because other streaming hardware and software have yet to develop to support this video protocol.
Who Should Use SRT?
SRT is the preferred protocol of many members of the SRT Alliance. This is a group of companies in the technology and telecommunications space that are dedicated to pushing SRT to the forefront of the live streaming industry because they believe it is the best protocol for streaming video.
The SRT Alliance was founded by Haivision, the same company that developed the video streaming protocol. Some major members of the SRT Alliance include Microsoft, Telestream, Alibaba Cloud, Comcast, Eurovision, and AVID.
If you are using technology that is supported by any of the SRT Alliance members, you should be able to easily incorporate SRT video streaming protocol into your streaming setup.
Pros of Using SRT:
- Secure: SRT includes top-of-the-line security and privacy tools so that broadcasters can rest assured that their streams remain safe and sound
- Compatible: SRT is device and operating system agnostic, meaning that it can deliver streams to most internet-enabled devices
- Low latency: Low latency streaming is a major value add for professional broadcasters. SRT achieves low latency streaming with the support of error correction technology
Cons of Using SRT:
- Not yet widely supported: like WebRTC, SRT is still a bit futuristic. The streaming industry will need to catch up before this video protocol is a standard
How to Choose Video Protocols for Your Stream
Do you know which video protocols are best for professional live streaming?
To recap, there are many video streaming protocols in existence today, and many of these can be used for live video streaming. When it comes to what protocol to use for streaming media, the answer is, it depends on your specific needs.
As we covered above, all of the protocols discussed here have specific use cases for specific broadcasters. However, when taking everything into account, HLS comes out on top, especially in terms of codec compatibility, all-device compatibility, HTML5 video player native support, and adaptive-bitrate streaming capacity.
Our takeaway recommendation here is simple: for now, most broadcasters should stick to using HLS for delivery and RTMP for ingestion. HLS is our choice for video streaming standard for the best video streaming protocol.
Of course, some users may find other protocols better for their needs. However, whether you want to stream live video on your website, do live streaming of sports events or broadcast professional events and gatherings live, HLS is generally the best way to go.
Keep an eye out for SRT and WebRTC as they make their way to the forefront of the online streaming industry in the future.
Conclusion
Although streaming protocols and related technology are a bit complex, they are totally approachable when broken down into smaller, more digestible ideas.
We hope this post has helped clarify the purpose of a protocol for video streaming and the relation between video streaming protocol, codec, and container format. We trust that you are equipped to choose and use the right video streaming protocol for your needs.
Leave a Comment