Streaming protocols
The media engine outputs your live stream in multiple protocols to ensure broad device and player compatibility. The following output protocols are supported: HESP and HLS.
HESP — High Efficiency Streaming Protocol
HESP is a next-generation streaming protocol designed for ultra-low latency live delivery. It is the default and recommended output protocol for the Dolby OptiView Live platform.
- Ultra-low latency — delivers end-to-end latency in the 1 to 5 seconds range, significantly lower than traditional HLS.
- Fast channel switching — viewers experience near-instant startup and channel changes.
HLS (CMAF) — HTTP Live Streaming
HLS is the industry-standard protocol developed by Apple for delivering live and on-demand content over HTTP. The media engine outputs HLS using modern CMAF (fragmented MP4) segments.
- Broad compatibility — supported by virtually all modern browsers, devices and players.
- Higher latency — compared to HESP, HLS typically introduces several seconds of additional latency.
HLS (MPEG-TS)
HLS with MPEG-TS segments is an older variant of HLS that uses traditional transport stream segments instead of CMAF.
Only use HLS MPEG-TS if you are targeting a platform that genuinely does not support CMAF-based HLS — for example, certain legacy set-top boxes or embedded devices. In all other cases, use the standard CMAF HLS output, which offers better performance and broader modern device support.
API example
You can configure output protocols via the API using the outputs object when creating or updating an engine.
POST https://api.theo.live/v2/channels/{channelId}/engines
{
"name": "my-engine",
"region": "europe-west",
"quality": {
"abrLadderId": "your-abr-ladder-id"
},
"outputs": {
"hesp": true,
"hls": true,
"hlsTs": false
}
}