Within the early days of streaming, the Actual-Time Messaging Protocol (RTMP) was the de facto commonplace for transporting video over the web (or in laymen’s phrases, streaming). RTMP is a TCP-based protocol designed to keep up persistent, low-latency connections — and by extension, clean streaming experiences.

The protocol began out as the key sauce behind dwell and on-demand streaming with Adobe Flash Participant. As a result of this fashionable Flash plugin powered 98% of web browsers in its heyday, RTMP was used ubiquitously.

The vast majority of encoders at this time can transmit RTMP, and most media servers can obtain it. Even large social media gamers like Fb, YouTube, and Twitch settle for it. Nonetheless, RTMP streams run into compatibility points relating to playback on fashionable browsers and gadgets.

On this article, we’ll take a look at the RTMP specification, the historical past behind RTMP streaming, the way to begin streaming with an RTMP encoder, and various protocols to contemplate.

What Is RTMP?

The RTMP specification is a streaming protocol initially designed for the transmission of audio, video, and different knowledge between a devoted streaming server and the Adobe Flash Participant. Whereas as soon as proprietary, RTMP is now an open specification.

In line with Adobe:

“Adobe’s Actual Time Messaging Protocol (RTMP) offers a bidirectional message multiplex service over a dependable stream transport, comparable to TCP [RFC0793], meant to hold parallel streams of video, audio, and knowledge messages, with related timing data, between a pair of speaking friends.”

RTMP Streaming: A Snapshot 

• Audio Codecs: AAC, AAC-LC, HE-AAC+ v1 & v2, MP3, Speex
• Video Codecs: H.264, VP8, VP6, Sorenson Spark^®, Display screen Video v1 & v2
• Playback Compatibility: Not broadly supported
  • Restricted to Flash Participant (which has been discontinued by Adobe), Adobe AIR, RTMP-compatible gamers
  • Not accepted by iOS, Android, most browsers, and most embeddable gamers
• Advantages: Low latency and minimal buffering
• Drawbacks: Not being up to date or supported
• Latency: 5 seconds
• Variant Codecs: RTMPT (tunneled by HTTP), RTMPE (encrypted), RTMPTE (tunneled and encrypted), RTMPS (encrypted over SSL), RTMFP (layered over UDP as a substitute of TCP)

How Does
RTMP Streaming Work?

Macromedia (which is at this time Adobe Programs) developed the RTMP specification for high-performance transmission of audio and video knowledge. RTMP maintains a continuing connection between the participant shopper and server, permitting the protocol to behave as a pipe and quickly transfer video knowledge by to the viewer.

As a result of RTMP sits on prime of the Transmission Management Protocol (TCP), it makes use of a three-way handshake when transporting knowledge. The initiator (shopper) asks the accepter (server) to begin a connection; the accepter responds; then the initiator acknowledges the response and maintains a session between both finish. Because of this, RTMP is kind of dependable.

Historical past of RTMP Streaming

Flash Participant and RTMP have been the dominant supply mechanisms for dwell streaming up till the early 2010s. When used collectively, these applied sciences assist lightning-fast video supply with round 5 seconds of latency. However HTML5 video streaming, open requirements, and adaptive bitrate supply ultimately edged RTMP streaming out when it got here to last-mile supply.

Why? Though RTMP works effectively, it traditionally encountered points getting previous firewalls. And as a stateful protocol, RTMP additionally requires a devoted streaming server, making it resource-heavy. The writing on the wall got here when Adobe introduced the loss of life of Flash — which occurred on December of 2020.

The trade now favors HTTP-based (Hypertext Switch Protocol) protocols that use plain-old net servers. Utilizing these applied sciences improves scalability and viewing expertise by permitting native servers to cache streaming content material. With this transfer, adaptive bitrate streaming has develop into extra frequent, permitting broadcasters to optimize content material for viewers’ gadgets and connectivity.

Fewer gadgets assist Flash (and by extension RTMP) than ever earlier than. In Adobe’s personal phrases, content material distributors are inspired “emigrate any present Flash content material to… new open codecs.”

Take a look at our weblog on The Historical past of Streaming Media for a extra detailed look.

So, Is RTMP Useless?

Flash’s end-of-life date was overdue. However the identical can’t be mentioned for RTMP. RTMP encoders are nonetheless a go-to for a lot of content material producers, and a whopping 76.6% of respondents to our 2021 Video Streaming Latency Report presently use it for ingest.

Which streaming codecs are you presently utilizing for ingest?

Many broadcasters overcome restricted playback assist by initially encoding their dwell streams with RTMP after which transcoding the content material for supply to a spread of gamers and gadgets utilizing a streaming server or service.

In different phrases, RTMP streaming is alive and effectively for content material contribution — simply not last-mile supply.

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Typical
RTMP Reside Stream Workflow

Content material distributors aren’t restricted to 1 streaming
protocol from seize to playback. In actual fact, repackaging a dwell stream into as
many protocols as potential helps guarantee broad distribution.   

As a result of at this time’s HTML5 gamers require HTTP-based protocols like HLS, a media server or streaming service can be utilized to ingest an RTMP stream and transcode it right into a extra playback-friendly various. Whether or not the RTMP stream is coming from an IP digital camera, cellular app, or broadcast-grade encoder, Wowza’s dwell streaming platform makes the conversion and supply course of seamless.

Robert Gibb at StackPath writes:

“A media server is an absolute necessity if you wish to leverage RTMP for dwell streaming. Wowza Streaming Engine, for instance, is a broadly used streaming software program for dwell and on-demand video that may be put in on any server.”

The most typical dwell streaming workflow out there’s RTMP to HLS. Utilizing a mix of RTMP and HLS helps maximize compatibility with out pushing latency too excessive. This structure additionally permits broadcasters to make use of well-supported protocols on both finish of the dwell video supply chain. Virtually all software program and {hardware} encoders assist RTMP, and the identical could be mentioned for HLS on the playback facet.

Methods to Set Up an RTMP Stream

To ship an RTMP stream throughout the web, you’ll want to begin with an RTMP-compatible digital camera or encoder. Chances are you’ll be utilizing an IP digital camera, software program encoder, or {hardware} encoder. We suggest the free OBS software program for anybody getting began.

When you’ve chosen the supply encoder to your RTMP stream, you’ll need to choose an answer for video transcoding and supply. We provide the Wowza Streaming Cloud service as an out-of-box resolution or the Wowza Streaming Engine software program for anybody requiring to deal with their video infrastructure on premises. To discover ways to join an RTMP encoder to Wowza’s video platform, try these assets:

• Join an RTMP Encoder to Wowza Streaming Cloud
• Join an RTMP Encoder to Wowza Streaming Engine

After connecting your RTMP encoder to the Wowza platform, you’ll simply must determine which format(s) you’d like to make use of for supply. We’ve included two tutorials under, one displaying the way to arrange an RTMP server for HLS supply utilizing Wowza Streaming Engine, and one other displaying the way to convert an RTMP stream into WebRTC utilizing Wowza Streaming Cloud.

Setting Up an RTMP Server for HLS Supply

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Changing RTMP to WebRTC Utilizing Wowza Streaming Cloud

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Testing Your RTMP Workflow

To check out your workflow, we provide a Check Participant with assist for MPEG DASH and HLS on Safari. You’ll discover that the ‘Adobe RTMP’ tab requires the set up of Adobe Flash Participant. That’s as a result of native in-browser assist is not frequent, and Flash itself is unsupported.

Different choices embrace the free VLC Participant or industrial gamers like THEOPlayer. You’ll discover that no matter which HTML5 participant you go along with, RTMP playback assist not exists. In different phrases, transcoding is important for an RTMP stream. And by streaming with Wowza, you’re capable of choose the very best codecs for multi-device supply.

Concerns When Changing RTMP

The very best protocol to your
workflow will rely in your use case. You may try the professionals and cons of every protocol on this weblog. However to begin, we’d suggest
evaluating your choices primarily based on the issues under:

• Scalability
• Latency
• High quality of expertise (adaptive
  bitrate enabled, and so forth.)
• Use (first-mile
  contribution vs. last-mile supply)
• Playback assist
• Proprietary vs. open
  supply
• Codec necessities

Transcoding RTMP dwell streams into adaptive HLS and DASH codecs stays a standard observe — and could be the very best place to begin. That mentioned, WebRTC shall be higher suited to anybody requiring sub-500ms latency, and it may be used for each ingest and egress.

RTMP Options for Ingest

Whereas RTMP continues to be commonplace for first-mile contribution, that’s starting to alter. Trade leaders predict that open-source protocols like Safe Dependable Transport (SRT) and Internet Actual-Time Communications (WebRTC) may develop into commonplace.

SRT

SRT is an open-source know-how designed for dependable and low-latency streaming over unpredictable public networks. It competes instantly with RTMP and RTSP as a first-mile resolution however continues to be being adopted as encoders, decoders, and gamers add assist.

In line with Deloitte: 

“Legacy protocols comparable to real-time messaging protocol (RTMP), developed over a decade in the past to encode video and transfer it throughout networks to purchasers, will doubtless be displaced by newer options comparable to Safe Dependable Transport (SRT), designed to additional lower latency and meet the calls for of dwell and on-demand streaming.” 

WebRTC

WebRTC is a well-liked ingest protocol in workflows that require sub-second streaming or easy, browser-based publishing. By swapping out an RTMP encoder for a WebRTC-based video supply, you’re capable of get rid of the necessity for extra tools. This makes it simple to seamlessly broadcast a dwell stream utilizing only a net browser.

Streaming distributors are additionally working so as to add WebRTC assist to encoding software program and {hardware} by the creation of the WebRTC HTTP Ingest Protocol (WHIP). At Wowza, WebRTC is the underlying know-how powering our Actual-Time Streaming at Scale characteristic for Wowza Streaming Cloud, and we’re constructing WHIP assist into our future OBS implementation for the characteristic.

Take a look at our video weblog, Utilizing WebRTC as an RTMP Different, to study extra.

RTMP Options for Egress

For last-mile supply, Apple’s HTTP Reside Streaming (HLS) and MPEG-DASH lead the pack, adopted by WebRTC.

HLS and DASH

HLS is the commonest protocol in use for dwell streaming at this time, employed by greater than 70% of individuals in our 2021 Video Streaming Latency Report.

Which streaming codecs are you presently utilizing for supply?

MPEG-DASH is the open-source various to HLS and a regular within the trade.

Whereas HTTP-based protocols have gotten warmth prior to now for injecting way more latency that RTMP, that’s anticipated to alter. Low-latency CMAF for DASH and Low-Latency HLS promise to assist low-latency streaming at scale — and thus delivering the very best of each worlds.

WebRTC

The one real-time various to RTMP is WebRTC. The WebRTC framework permits customers to speak instantly by their browsers with sub-500ms latency.

Giant-scale broadcasting was once an impediment when utilizing WebRTC, however Actual-Time Streaming at Scale for Wowza Streaming Cloud now ensures sub-second supply to as much as 1,000,000 viewers. The characteristic can be utilized with WebRTC and RTMP ingest, as proven within the workflow under.

Workflow: Actual-Time Streaming at Scale With Wowza Streaming Cloud

Conclusion

It doesn’t matter what sort of streaming structure you’re attempting to construct, Wowza makes it occur. Our full-service platform can energy any workflow with reliability as well. We provide protocol flexibility on the ingest facet in addition to on the supply facet — which means you’re capable of design the very best streaming resolution to your use case somewhat than sticking with one prescriptive workflow.

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Extra Sources

• The Full Information to Reside Streaming
• Low-Latency Streaming Applied sciences: The Key to Interactive Video
• Utilizing WebRTC as an RTMP Different

About Traci Ruether

As a Colorado-based B2B tech author, Traci Ruether serves as Wowza’s content material advertising and marketing supervisor. Her background is in streaming and community infrastructure. Other than writing, Traci enjoys cooking, gardening, and spending high quality time together with her kith and kin. Comply with her… View extra