You may not realize it, but the internet is rife with protocols that we use every day. For example, if you’ve watched video content on platforms like Facebook Live, Youtube Live, Linkedin Live, you may have used RTMP.
So what is RTMP? And how does it relate to live streaming content?
RTMP stands for “real-time messaging protocol.” It’s a powerful streaming protocol, developed by Adobe (previously Macromedia) for live streaming.
If you’ve decided to test the live streaming field, you’ll have to come to grips with not just technical terms like RTMP live streaming, but several others, too.
In this blog post, we’ll dive into questions like: what is RTMP streaming? How do you set it up? And we’ll also break down the nuances of RTMP vs HTTP streaming.
Ready to learn? Buckle up.
RTMP stream: three important questions
Before we deal with the technical stuff, let’s answer three questions. We’ll be referring to the terms in the questions quite a bit.
What is a streaming protocol?
A streaming protocol is what runs your live streaming show by delivering the data, audio, and video over the internet from your set up station to the viewer’s screen.
RTMP stream is just one streaming protocol, albeit a powerful one. Other common names are HTTP streams, MPEG-DASH, MSS, and more — we’ll talk about these in a bit.
What is latency?
Latency is the time between your action and a web app’s response. In terms of video live streaming, latency refers to the delay in transferring the data from your end to your viewer’s side.
Frankly, you can’t compromise with this delay. When live streaming, a simple lag can disrupt both the viewer experience and the flow of conversation especially when using tools like live chat, live Q&A, and audience polling.
What is ABS?
ABS is adaptive bitrate streaming, also known as ABR streaming. It’s a technique used to compress and alter a stream’s video quality to match the available bandwidth.
To simplify it further, ABS is what ensures that your viewer sees the highest video quality with the available bandwidth. If the bandwidth is limited, say due to poor network connection, ABS automatically takes the video quality down to what the bandwidth can show.
What is RTMP streaming?
RTMP stream is a live streaming protocol that offers high-performance transmission of audio, video, and data from an encoder to a server that distributes the signal over the internet.
In its heyday, RTMP streams enjoyed a lot of fame as the chief protocol for live streaming used with Adobe’s Flash Player.
Despite Adobe’s decision to sunset its Flash player, RTMP streaming continues on with the help of RTMP-enabled encoders. In fact, many streaming providers and encoders support RTMP live streams, including Vimeo.
So what’s keeping RTMP video streaming alive and kicking? Let’s look at all the benefits and setbacks to get a complete picture.
Pros of RTMP streaming:
- Applauded for low latency streaming.
- Creates a reliable streaming experience by maintaining constant contact between the video player and server – an advancement over its predecessors.
- Provides secure, cloud-based streaming through RTMPS, which offers convenience and security for live streaming needs.
What is RTMPS?
RTMPS is a secure form of RTMP that minimizes the risks of cloud-based streaming. For organizations looking for a secure way to live stream internally for all-hands meetings or town halls, RTMPS is paramount. As an example, Vimeo uses RTMPS as the default protocol for Livestream Studio to make it easier and safer to stream.
Cons of RTMP streaming:
- It doesn’t support high-resolution video and video compression methods like VP9, AV1, and more.
- RTMP live stream is no longer accepted for iOS, Android, most embedded players, and several browsers. What’s more, certain networks block the RTMP port by default, which requires special firewall modifications to allow passage to the blocked network. Again, this limits scalability.
- RTMP live streaming is vulnerable to data loss. In the case of network issues, it can quickly lose data over a few seconds, which can disrupt the stream.
How does RTMP streaming work?
A RTMP stream works by chopping the data into smaller fragments of audio and video known as packets. These are sent independently via several virtual channels defined by the streaming protocol, which explains what makes RTMP live streaming efficient.
Does RTMP use TCP or UDP?
RTMP uses transmission control protocol (TCP) which facilitates the exchange of data between devices in a network. The RTMP stream sits on top of TCP where a three-way handshake enables data transportation. Here’s how: the initiator asks the server to start a connection (first handshake). When the server responds (second handshake), the initiator acknowledges it (third handshake) and a reliable connection is established.
RTMP has two use cases:
1. First-mile delivery
Also known as video contribution where a RTMP stream is used to send video between an encoder and server.
2. Last-mile delivery
In this case, RTMP live stream is used to transmit data between a server to a video device that uses a Flash player.
Since streaming video with RTMP isn’t supported by all video devices, RTMP streaming isn’t used for last-mile delivery anymore. RTMP encoders, however, help with first-mile delivery.
But if RTMP is working on the first-mile delivery front only, how does the last-mile delivery roll? Good question.
For last-mile delivery, the industry uses other streaming protocols with the following two leading the pack:
- Apple’s HTTP Live Streaming (HLS) or HTTP in short
- MPEG Dynamic Adaptive Streaming over HTTP (MPEG-DASH)
Other two names that you might occasionally hear alongside these two are:
- Microsoft’s Smooth Streaming (MSS)
- Adobe’s HTTP Dynamic Streaming (HDS)
However, we won’t be discussing these in depth as MSS has been discontinued and HDS can’t be used with HTTP servers, which limits its use.
Streaming protocols for last-mile contribution
With their introductions out of the way, let’s review the advantages and disadvantages of each streaming protocol:
HTTP or HTTP Live Streaming (HLS)
Developed by Apple, HLS is widely used by browsers, mobile devices, and other streaming players. Since it’s widely used, it’s also easy to scale, which counts as its greatest advantage.
On top of that, HTTP uses ABS streaming. This automatically adjusts video quality based on the viewer’s bandwidth availability.
However, HLS shows high latency of 6-30 seconds. Naturally, this is a serious downside in contrast with a RTMP live stream. There’s also word on the streets that some broadcasters find implementing HLS overly complicated.
MPEG-DASH
MPEG-DASH is the brainchild of the industry expert on audio and video standard, Moving Pictures Expert Group, spelled out in the name (MPEG).
It’s an open-source protocol that is applauded for being codec-agnostic. Meaning, it can use content that’s encoded with any coding format such as VP9, H.265, and so on.
But here’s the catch: because Apple prioritizes its software, support for MPEG-DASH takes second place. It also showcases higher latency between 6-30 seconds – again, higher than what RTMP offers.
WebRTC
There’s also a third, open-source streaming protocol used to transmit data through browsers with sub-500 mg latency. This ultra-low latency is the reason for all the credit that WebRTC enjoys.
Unfortunately, it’s not scalable as it’s designed for small broadcasts. WebRTC needs customizing to be used for large-scale live streaming.
Prepping up for streaming to a broad audience? We’ve got you covered with two guides on how to live stream an event and how to plan a virtual event.
RTMP vs HTTP streaming
By now, you should have an idea of how RTMP and HTTP streams pit against each other.
RTMP streaming enjoys the spotlight due to its low latency and minimal buffering. Its stronghold suffers when it comes to scalability.
On the flip side, HTTP is a streaming champ due to its wide application and improved viewing experience, thanks to ABS. The problem? Low latency – something viewers can’t forgive as most quit watching a spotty stream that’s delayed by only 90 seconds. Below, we’ve laid out the main differences between RTMP and HTTP regarding latency, playback compatibility, firewall restrictions, and audio and video codecs.
But, contrary to what you might think, HTTP and RTMP protocols work with each, rather than against each other. How? By complementing one another, working where one lags behind. This is exactly how live streams work today.
How to set up RTMP for your live stream
Now you have a complete rundown of RTMP streaming, how it compares to other streams, and how things work in the live streaming industry. Let’s walk through how to set up your RTMP live stream.
To get started, you’ll need a RTMP-enable encoder and RTMP server. You’ll find details on these two below.
For now, here are your steps for setting up a RTMP stream specifically with Vimeo Live:
- Add the RTMP stream on Livestream Studio’s setting under the Input tab.
2. To configure the server, authenticate the stream under the gearwheel icon by adding your username and password.
3. Configure your encoder next by entering your Stream Name and RTMP URL. Fetch these from the Livestream Studio, under the General tab. In your third-party encoder, open your RTMP settings and enter the RTMP URL and Stream Name from the Studio into the corresponding fields.
For an in-depth look at this set up, check out how to set up Livestream Studio as a RTMP Server.
How do I use RTMP?
To use a RTMP live stream, you’ll need a RTMP-enabled encoder and a server to receive and stream the data you get. Use Vimeo Live as your RTMP receiving server and pair it with a compatible RTMP-enabled encoder to start streaming.
Best RTMP encoders for live streaming
Pick from these RTMP-enabled hardware encoders. The best part? They’re all compatible with Vimeo Live:
- Open Broadcaster Software (OBS)
- Wirecast
- Teradek Encoder Line
- XSplit Broadcaster
Want more details on how to set up one of these encoders with Vimeo Live? Dive into this encoder guide.
A RTMP server: Vimeo Live
This server distributes the RTMP stream to your audience’s players by converting the RTMP stream into another streaming protocol for last-mile delivery.
Now, where can you find yourself a reliable RTMP server? We suggest you take Vimeo Live for a drive. Not only does it take care of the technical, streaming protocols conversion part, but it also handles privacy and security measures while letting you broadcast in full HD with ABS.
With Vimeo Live, you can also simulcast or stream on multiple channels at a time and engage your audience with features like live polls, live Q&A session, email capture, audience chat, and custom calls to action.The best part? Vimeo keeps your live stream running even if your internet connection hits a snag by letting you create a backup livestream.
Looking for more production tips for setting up a live stream?
Check out our Master Class session on live streaming tech, equipment, and setup.
Check out our Master Class session on live streaming tech, equipment, and setup.
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“It’s very easy for people who aren’t necessarily technical to get started. It’s plug and play. And you have access to a large global audience without necessarily having a lot of technical knowledge”
David Haug, Senior video producer, Deloitte
How do I find my RTMP URL?
This depends on the live streaming platform you use. If you’re using Vimeo Live, you can find your RTMP URL by clicking the Editor icon and selecting the Live Tools menu. Scroll to the bottom until you spot the RTMP Input option. Select Get Link there to get your Stream Key and a Server URL.
Wrap up: stream anywhere with RTMP
At the end of the day, RTMP is a technical protocol for streaming video content. The greatest advantage is that it’s universal across many destinations including social platforms like Facebook, Youtube,and Linkedin allowing streamers to broadcast anywhere and everywhere. And with RTMPS, you have a secure solution for cloud-based streaming right at your fingertips.
