Connect Moblin to OBS: SRT, SRTLA & RTMP

Moblin is a free, open-source IRL streaming app for iOS, “IRL” just means streaming live from out in the real world instead of from a desk. This guide shows you how to set it up so your iPhone’s camera sends video to a StreamRelay endpoint (your personal drop-off address on our servers) over SRT, SRTLA or RTMP, the ways of sending live video across the internet. From there it lands in OBS, the free studio software on your PC.

Before you start

• Moblin installed from the App Store.
• A StreamRelay endpoint, the dashboard gives you a ready-made publish URL (the web address Moblin sends video to, with your secret publish key already baked in). From €9.99/month.
• OBS on your PC, ready to pull the feed, meaning OBS reaches out and grabs the video from the relay.

Step 1: Add a stream destination in Moblin

Open Moblin → Settings → Streams → Add stream. Give it a name like “StreamRelay” so you recognise it later.

Step 2: Enter the StreamRelay URL

Copy the matching publish URL from your dashboard into the stream destination:

• SRT (recommended for cellular):

  srt://<id>.ingest.stream-relay.eu:4000?streamid=publish:live/<slug>:_:<publishKey>

• SRTLA (for connection bonding): works like SRT but bonds multiple connections (e.g. Wi-Fi plus two or three SIM cards) into one sturdier link, handy when you’re driving through dead spots or tunnels. Moblin supports SRTLA natively.

  srtla://<id>.ingest.stream-relay.eu:5000?streamid=publish:live/<slug>:_:<publishKey>

• RTMP (simplest):

  rtmp://<id>.ingest.stream-relay.eu:1935/live/<slug>?pass=<publishKey>

Use the publish URL from your dashboard (it carries the secret publish key, keep it private). Moblin works out which protocol to use from the start of the URL (the srt://, srtla://, or rtmp:// part), so you don’t have to set it anywhere else.

Step 3: Set resolution and bitrate

Pick 1080p30 or 720p60 to start. Bitrate is how much data your video uses each second, higher looks sharper but needs a stronger connection. Set it to what your weakest signal can comfortably handle: 4,000 – 6,000 kbps on solid 5G/Wi-Fi, 2,500 – 3,500 kbps on a shaky connection. With SRT or RTMP everything runs over a single connection, and if it drops, the stream drops. With SRTLA, Moblin bonds several connections that arrive together at one endpoint. The sum of them counts, and the remaining links cover for one that fails as long as they can still carry your bitrate. If every link goes down at once (a long tunnel, a dead zone), bonding cannot help either. Leave some headroom instead of running at the limit.

Step 4: Go live

Tap Go Live. Moblin now sends to StreamRelay. Add the separate read URL as a Media Source in OBS. Follow the OBS setup guide for the steps.

SRT, SRTLA, or RTMP in Moblin?

Use SRT when your signal comes and goes, it quietly re-sends any bits of video that got lost along the way, so the picture stays smooth on a single link. Use SRTLA when no single connection holds up on its own, driving, tunnels, dead spots, and you can bond multiple connections together. Use RTMP when you just want the simplest setup. Full comparison: SRT vs SRTLA vs RTMP.

Frequently asked questions

Does Moblin support SRT? Yes, paste an srt:// URL as the stream destination. Moblin also supports RTMP.

Does Moblin support SRTLA? Yes, natively. Paste an srtla:// URL as the stream destination to bond multiple connections into one sturdier link.

Why won’t Moblin connect to my endpoint? Check the URL scheme, port, and stream-id/key are exact, and that your StreamRelay endpoint is active.

Keep reading

New to this? Read the phone-to-OBS guide. Curious how Moblin compares to IRLPro and Larix? See mobile streaming apps compared.