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16 December 2021

SRT takes aim at ‘dated and dwindling’ RTMP to snatch remaining 47%

Haivision’s ‘Ultimate Guide to SRT’ landed in Faultline’s inbox with a splash, but it quickly became apparent that nothing is new with the Secure Reliable Transport low-latency streaming protocol, or ultimate for that matter.

What we did learn from the glorified sales pitch is that an overwhelming 53% of the world’s broadcasters have now adopted SRT, according to Haivision’s own Broadcast IP Transformation survey, which is hardly a going to be an unbiased sample size. However, while emphasis is – as always – on the free and open-source code base of SRT, with no royalties or hidden subscription fees, this opportunity at 47% of broadcasters still to adopt SRT could be worth $billions to the SRT community.

This is why the technology and others like it (RIST, Zixi, RTMP) will continue to be vital during the next decade of broadcast evolution, but will SRT ever become the de facto video transport protocol used in broadcast workflows, to the detriment of rival technologies? With SRT most often compared side by side with RTMP, Haivision is channeling efforts into encouraging the industry away from this legacy protocol.

The latest report emphasizes SRT consistently outperforming RTMP for both latency and video quality, while claiming that support for RTMP’s “dated” technology is “dwindling.” Unlike SRT which is codec agnostic, RTMP doesn’t support newer video or audio codecs, so that means no HEVC, AV1 or VP9.

We recall our last conversation with the Haivision executive team, when we suggested Haivision was growing complacent with its marketing, lacking the competitive snarl required to become the de facto industry standard. As expected, that comment didn’t go down well, but here we are now with Haivision commissioning entire white papers dedicated to trashing rival technologies – including a separate report to this one titled RTMP vs SRT.

It looks like our advice sunk in eventually. Initially, we pondered why Haivision isn’t dedicating more resources to slandering a newer rival protocol like RIST, instead of a legacy one like RTMP, but the numbers are telling. While SRT is the second most popular transport protocol globally in the broadcast sector, at 53%, it trails RTMP on 61%. Meanwhile, RIST is used by just 3%, according to Haivision, which bizarrely is behind the ‘None’ option, according to Haivision’s survey results. Remember, we cautioned not to take this as gospel, but that gulf is alarming, if the numbers are to be trusted.

SRT has grown to prominence with support for resending of lost packets even over unreliable networks, while RIST is much the same but is a standardized protocol, with SRT and RIST each coming with their own pros and cons.

The sluggishness of RIST adoption is strange considering RIST was defined by the shortcomings of SRT in the professional video industry, based on thorough research into what broadcasters need from a video transport protocol. RIST claims better ability to deal with congestion over IP links than SRT, when networks become more troublesome. Multiplexing of multiple streams into the same tunnel is another area where RIST comes into its own – known for being better at bonding over multiple links.

But at the end of the day, not all products and workflows are the same, and SRT is better suited to some workflows. We have also heard RIST Forum members claim that interoperability is an afterthought for SRT, but a priority for RIST.

It was April 2020 when Faultline scooped that famous exclusive from RIST Forum’s President, Dr. Ciro Noronha, about his desire to merge SRT and RIST. Unfortunately, the feeling was not mutual from the SRT camp, despite his proclamations that a merger would benefit everyone involved. Unfortunately, we think that ship has sailed, unless an unlikely candidate arrives to throw SRT dramatically off course.

Even though the ‘Ultimate’ white paper turned out to be something of a damp squib, it is fitting to close out Faultline’s final issue of 2021 with some SRT coverage – celebrating the meteoric rise since blasting onto the open-source scene during those fateful few days at IBC 2017, four years after SRT was first demonstrated on the RAI show floor.

Much the same in 2022, we expect, and so it’s also apt that Faultline has interviews this week with two vendors dabbling in low-latency technologies – Phenix and Nanocosmos.