Haivision and Wowza Launch SRT Alliance for Low-Latency Streaming
With live streaming taking off in 2016, latency has become a central issue for the industry. To reduce latency as much as possible, video streaming companies Haivision and Wowza Media Systems are joining together to launch an open source version of SRT (Secure Reliable Transport), a full-stack video transport protocol. Created by Haivision, SRT is a technology package and protocol that connects two endpoints to deliver low-latency video across lossy networks. Haivision first demonstrated SRT at IBC 2012.
A full-stack solution is most beneficial with wide support behind it, and so the two companies have formed the SRT Alliance. Distributed under an LGPLv2.1 license, SRT's source code is available on GitHub, along with sample applications. Developers are free to use SRT and even make and upload improvements. In the coming weeks, the alliance will publish an open source SRT Governance Model to clarify how contributions are vetted and merged.
Working across the pipeline, SRT can be applied to encoders, streaming servers, decoders, set-top boxes, and video players. The two companies note that SRT includes end-to-end security with AES encryption, network health monitoring, and simplified firewall traversal. It works on closed or open networks, including the internet. While conditions will vary, SRT with one to two percent packet loss should deliver latency in the 500ms range.
"While catering to audio and video streams, SRT is content agnostic and operates at the network packet level reconstructing the real-time behavior of the data stream at the receiving end, surviving network packet loss, out-of-order packets, jitter, and fluctuating round-trip time while maintaining low latency," explains Adam Yellen, vice president of software platforms for Haivision. "On the protocol level, one advantage of SRT is its ability to multiplex control and multiple data substreams into a single established stream. This makes it a lot more IT-friendly in the real world because data flow is predictable and can be easily controlled and monitored at the network infrastructure level."
SRT is currently used by the Haivision product line, while Wowza will incorporate SRT into its products starting with the Wowza Streaming Engine. Going forward, both Haivision and Wowza will contribute to the SRT source code. The two companies will demonstrate the SRT protocol from a second floor suite at the Renaissance Hotel during the NAB Show, which starts today.
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