How SRT Enables Low‑Latency, Reliable Live Streaming for Global eSports Events

What is SRT?

SRT (Secure Reliable Transport) is an open‑source, royalty‑free UDP‑based transport protocol co‑developed by Haivision and Wowza, designed to provide secure and reliable low‑latency transmission for live video streams, overcoming TCP’s high latency and jitter on long‑distance links.

In live streaming, SRT can be used in two main ways:

TS over SRT : Directly transport MPEG‑TS streams over SRT, a method adopted by Haivision hardware and OBS, and used in major events such as the 2019 League of Legends World Championship.

RTMP/FLV/HLS/DASH over SRT : Tencent Video Cloud uses SRT as a transport layer to convert any TCP‑based application protocol to SRT, supporting push and pull streams while remaining compatible with existing live‑streaming systems.

Why Choose SRT?

During the 2020 LPL Mid‑Season Cup, teams from LPL and LCK competed online due to the pandemic, requiring real‑time transmission of video signals between Shanghai and Seoul. The challenges included maintaining low latency and reliable delivery across long distances.

SRT’s application‑layer retransmission provides higher reliability under packet loss, keeping application‑layer loss low and ensuring stable transmission even when packet loss exceeds 30%, where protocols like QUIC start to fail.

Although SRT’s aggressive retransmission consumes more bandwidth, it is well‑suited for scenarios with limited concurrent streams that demand stability.

SRT has become a standard for Haivision hardware and OBS, and Tencent Video Cloud has adopted it as the primary transport protocol.

Performance Comparisons

Tests with 60 fps video at bitrates of 1 Mbps, 5 Mbps and 10 Mbps show that under the same network packet‑loss rates, SRT’s higher application‑layer retransmission results in fewer lost frames and stable delivery.

In a 20 Mbps stream from Los Angeles to Shanghai with 1–2 RTT latency, different packet‑loss rates significantly affect retransmission rates. SRT maintains stable transmission where other protocols struggle.

Comparisons with other protocols over dedicated lines demonstrate SRT’s superior performance in long‑distance transmission.

Tencent Video Cloud Optimizations

Tencent Video Cloud has further enhanced SRT for various live‑streaming scenarios:

Protocol optimizations (support for streamid, vhost, multiplexing).

Live‑mode adjustments to tolerate packet loss while improving resilience under weak network conditions.

Efficiency improvements for non‑TS data, dynamically adjusting chunking and transmission mechanisms.

Seamless integration with Tencent’s CDN, allowing SRT for upstream push and conventional RTMP/FLV/HLS for downstream.

Performance enhancements leveraging multi‑core CPUs, positioning SRT between transport and application layers for scalable, low‑latency streaming.

These upgrades, combined with global CDN distribution, multi‑region deployment, intelligent routing, and robust authentication, have supported major events such as the 2019 League of Legends World Championship, national parades, and Double‑11 shopping festivals.

MediaConnect and Global Transmission

Beyond esports, Tencent’s MediaConnect product uses SRT to provide high‑speed, reliable video transport across continents. Users can configure a Flow to enable SRT‑based transmission between selected source and destination regions, with support for protocol conversion (RTMP/RTP/UDP/SRT) and integration with CDN or MediaLive.

Tests show that 100–200 Mbps video streams can be reliably transferred between two trans‑ocean endpoints with latency kept under 500 ms.

MediaConnect facilitates stable, accelerated sharing of audio‑video data for transcoding, production, and distribution worldwide, meeting low‑latency and security requirements.

Future of Remote Production

Tencent Cloud plans to combine SRT low‑latency transmission with cloud‑based production tools such as cloud‑based switchers, editors, and monitoring, creating an end‑to‑end streaming platform that eliminates the need for physical cabling and enables multi‑site video composition for immersive live experiences.

Overall, SRT, together with Tencent Video Cloud’s optimizations and MediaConnect, provides a reliable, low‑latency solution for global live video transmission across diverse scenarios.