High Efficiency Streaming Protocol

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High Efficiency Streaming Protocol (also known as HESP) is an HTTP-based adaptive bitrate streaming protocol that enables high-quality streaming of media content over the Internet delivered from conventional HTTP web servers..,^[1] just like HLS and DASH. The technology was developed by THEO Technologies and made available via the HESP Alliance, which has Synamedia and THEO Technologies as founding members.^[2] HESP brings sub-second latency and a fast channel change, and is seen as a challenger of Low Latency HLS (LL-HLS, first released in 2009) and Low Latency DASH (LL-DASH, standardized in 2012).^[3]

HTTP-based streaming protocols such as HLS and DASH typically use a segment-based approach. This means a video is cut up into TCP segments of a few seconds each, which requires video players to wait until the start of a new segment to start playback. This approach increases channel change times and introduces additional latency. HESP leverages a frame-based streaming approach, which does not require a trade-off between live latency and channel switching time.^[4]

When all components of the video workflow are optimized for low latency, HESP can provide for sub-second latency.^[5]

HESP requires implementation in the packager and player, and support for range requests and Chunked transfer encoding (CTE) in the CDN.^[6]

Work on HESP started in 2018; it became an IETF information draft in May 2021^[7]

The HESP Alliance, launched in 2020, promotes and catalyzes the adoption of HESP. It consists of streaming vendors and media companies, including Synamedia, THEO Technologies, G-Core, EZDRM, Mainstreaming, NativeWaves and Hoki. The HESP Alliance technical working group is focused on further advancing the HESP standard^[8]