Broadcasting with Moblin

By the end, Moblin will be broadcasting to your stream key and you’ll see it on Streaming in the dashboard.

You need: any plan with a stream key · Moblin on iOS or Android · 5 minutes

The shortcut: the QR code

Moblin can read a QR code with the setup inside, so there’s nothing to type or paste out on the street.

1. In the dashboard, open Stream Keys and hit QR code on your key.
2. Leave the format on Moblin and hit Show QR code.
3. If you’re scanning it from another phone, hit Full screen and turn the brightness up.
4. Point your phone camera at it and open the link it offers: Moblin creates the stream, selects it, and the publish URL is already inside. If you’re already on the phone that has Moblin, there’s nothing to scan: tap Open in Moblin, under the code.
5. With the key on SRTLA or SRT, turn off Big packets: the code can’t set it, and Moblin creates the stream with it on, so it wouldn’t connect. The exact path is in Where Big packets is.
6. Check the bitrate and hit Go live.

The code comes from the Protocol and the Region the key has at that moment. If you change either, or you Rotate the key, scan it again: Moblin recognises the stream by its name and offers to replace it, so your list doesn’t fill up with duplicates.

The QR code is your key

That code carries your stream key inside. Anyone who photographs it can broadcast on your channel. That’s why the dashboard keeps it hidden until you hit Show QR code: don’t share it, don’t show it on stream and don’t leave it in a screenshot.

If you’d rather do it by hand, or your encoder isn’t Moblin, carry on with the steps below.

Before you start

Decide on the protocol. If you carry two SIMs (or a SIM and wifi) and you want Moblin to add them up, go for SRTLA. On a single connection, SRT does the job just as well. If in doubt, read Choosing a protocol.

Steps

1. In the dashboard, open Stream Keys.
2. On your key, set the Protocol selector to SRTLA (or to SRT).
3. Hit Publish to copy the URL. With SRTLA it starts with srtla://; with SRT, with srt://.
4. In Moblin, create a new stream and give it a name you’ll recognise.
5. Paste the publish URL into the stream URL field. Paste it whole: it already carries the server, the port and your key inside the streamid.
6. If Moblin asks for the stream id in a separate field, type publish: followed by your key, exactly as it appears at the end of the publish URL.
7. Set the bitrate below your plan’s cap (table below). If you’re moving around the street, leave yourself room: a bitrate that holds beats a high one that drops.
8. Turn off Big packets: Moblin creates SRT streams with it on. See Where Big packets is.
9. Hit Go live. In the dashboard, the key goes from No signal to Streaming and the Live signal card starts showing a Current bitrate.

Big packets has to be OFF

With Big packets on, the connection never gets established. The nasty part is the error Moblin shows: it looks like a credentials problem or a rejected key, so people start rotating the key and double-checking the URL when the only thing wrong is that checkbox. If Moblin talks to you about authentication and you’re dead sure about the URL, check Big packets before anything else.

Where Big packets is

It isn’t on the stream screen: Moblin keeps it among the advanced settings. Do it with the stream stopped, because the setting is locked while you’re live.

1. In Moblin, open Settings.
2. Scroll to the bottom and turn on Show all settings.
3. Go into Streams and tap your stream (if it came from the QR code, the one starting with Enhanced IRL).
4. Tap SRT(LA). It only shows up if the stream URL is srt:// or srtla://.
5. Turn off Big packets.

When you import the code again (after you Rotate the key or change the Region), Moblin offers to replace the stream. If you accept, it keeps the setting; if you add it as a new one, that new stream comes with Big packets on again and you have to repeat these steps.

Bitrate caps

This is the maximum the key accepts. It isn’t a target: it’s a ceiling.

Plan	Key cap
Stream Key Lite	9,000 kbps
Stream Key	9,000 kbps
OBS Basic	6,000 kbps
OBS Standard	6,000 kbps
OBS Pro	10,000 kbps

If your destination is a Cloud OBS, what goes out of it towards your platform has its own cap, different from this one.

Not working?

Moblin throws an error that sounds like authentication and never even connects. It’s Big packets. Turn it off and try again. If the message is stuck from a previous attempt, stop the stream, leave the screen and come back in.

Moblin says it’s broadcasting, but the dashboard is still on No signal. You’re using an old URL. It happens every time you change the Region or the Protocol, or you Rotate the key: the previous one stops working instantly. Go back to Stream Keys, copy again with Publish and paste it into Moblin over the old one.

You put srt:// instead of srtla:// and there’s no bonding. With srt:// Moblin uses a single connection even if you have two live. For it to add them up, the URL has to start with srtla:// and the key has to be on SRTLA in the dashboard.

Next step

• Choosing a protocol — when SRTLA is worth it and when it isn’t.
• Broadcasting with BELABOX — the other route with bonding.
• Unstable bitrate — if it connects but drops now and then.