SRT Streaming

Use SRT ingest for more resilient streaming on unreliable networks.

Overview

SRT is a UDP-based protocol with built-in recovery, ideal for mobile or long-haul networks. Meshcast accepts SRT ingest on registered accounts and routes it to WHEP or HLS playback.

Requirements

• Registered (free) Meshcast account or higher tier.
• SRT-capable encoder (OBS, Larix, Haivision Play, FFmpeg).
• UDP access to port 8890 on the assigned server.

Set up your SRT encoder

1. Copy your Stream ID and Publish Key Find your public Stream ID (st_...), private Publish Key (pk_...), and assigned server in the Meshcast dashboard or studio.
2. Build the SRT URL Use the credentialed SRT stream ID format below. The path is the public Stream ID, and the Publish Key is passed as the SRT password.
   srt://[server-ip]:8890?streamid=publish:[stream-id]:meshcast:[publish-key]&pkt_size=1316&latency=400000
3. Configure your encoder Set SRT mode to Caller, paste the full URL above, leave OBS Stream Key empty, and use a stable bitrate for the network.
4. Larix app note If Larix shows only NDI and WebRTC options, confirm you are using Larix Broadcaster (not Larix Player), and that you are adding a full destination URL that supports SRT Caller.
5. Start streaming Publish and confirm the stream appears in your Meshcast dashboard or viewer link.

Latency presets

OBS and FFmpeg use FFmpeg's SRT URL options. The latency value is measured in microseconds, not milliseconds.

• latency=200000 - 200 ms for clean wired networks.
• latency=400000 - 400 ms default recommendation for normal internet uplinks.
• latency=800000 - 800 ms for mobile, Wi-Fi, or congested uplinks.

Higher latency gives SRT more time to recover lost packets, but adds delay. If the stream still breaks up at 800 ms, lower the encoder bitrate before increasing latency further.

Playback options

• WHEP provides low-latency WebRTC playback for browsers.
• HLS is available for registered and paid tiers. Unregistered embeds are limited to meshcast.io/vdo.ninja, while registered can enable public embeds in account settings.
• For VDO.Ninja playback, see IRL SRT to VDO.Ninja. VDO.Ninja's &buffer=500 option applies to VDO.Ninja playback only, not to the Meshcast SRT ingest URL.