External encoder
Last updated: September 21, 2026
The External encoder page is where you point an RTMP encoder at your event. It works with software encoders such as OBS, vMix and Wirecast, and with hardware encoders. In event admin, go to Live → External encoder.
The page has four parts, and it is worth working through them in this order:
- Select live channel decides which channel your encoder streams into.
- Encoder settings gives you the server URL and stream key to copy, and the recommended encoder settings behind them.
- Re-streaming to other platforms forwards the same stream to another RTMP destination.
- Advanced playback settings controls how the player behaves for your viewers.
Select a live channel
A live channel carries the live encoder URL and the encoding settings your event streams with. Every event must have a live channel selected, and you need a separate live channel for each stream you run at the same time.
Choose one under Select existing live channel for this event. Shared channels are listed by name, with the transcoder template after it. An event specific channel is listed as Event specific live channel selected.
Shared channels and event specific channels
There are two kinds of channel.
- A shared account channel belongs to the account. Any event can select it, and its settings are shared by every event that uses it.
- An event specific live channel belongs to one event. Nothing else takes it while your event runs.
Create an event specific channel with the buttons under Create event specific live channel (stream key). Creating one replaces the event’s current live channel, and the first one you create comes with its own stream key. Do it before you configure your encoder, otherwise you will copy a stream key the event no longer uses. If you later swap the event specific channel for a different type, the stream key stays the same.
If you do not see those buttons, event specific live channels are not enabled for your account. Contact support, who can also add more shared channels to the account.
Live channel types
Each button creates a channel of one type. Which buttons you see depends on the account, so you may not see all five.
| Channel type | What it creates |
|---|---|
| 1080p video, 10s delay | A channel suitable for a 1080p video stream and 10 seconds delay |
| 1080p video, 20s delay | A channel suitable for a 1080p video stream and 20 seconds delay |
| 720p video, 10s delay | A channel suitable for a 720p video stream and 10 seconds delay |
| Audio, 10s delay | A channel suitable for an audio only stream and 10 seconds delay |
| Single bitrate video, 10s delay | A channel for single bitrate video delivery and 10 seconds delay |
The delay in the name is the live delay the channel is built for. A 20 second channel puts your viewers further behind the encoder than a 10 second one.
A single bitrate channel carries one quality only. Viewers get what you send and nothing smaller, so a viewer on a weak connection cannot drop down. Use it only when you know your audience has bandwidth to spare.
Match the channel to the event type
An audio event needs an audio channel, and a video event needs a video channel. If the two do not match, the page shows a red warning under the channel selector with a link to Videoplayer set up.
The event type itself is set in event admin under Build → Videoplayer set up. Fix the mismatch from whichever side is wrong. Either set the event type to match the channel, or come back here and create a channel that matches the event. The audio channel type is called Audio, 10s delay.
The warning can only appear when the selected channel has a type recorded on it. Older shared channels often do not, and for those no warning is shown even when the channel is wrong for the event. If your event is an audio event, check the channel yourself rather than waiting for a warning.
Web studio events do not need any of this. A studio created for an audio event takes an audio channel into use by itself.
Encoder settings
Two read-only fields hold everything your encoder needs.
- Server URL is the RTMP ingest address of the selected live channel.
- Stream key identifies your event’s stream on that server.
Copy both into your encoder. Most encoders ask for them as a server or URL field and a stream key field.
Both fields follow the channel you selected above, so select the channel first and copy afterwards. If you change the channel later, copy both again.
When the channel has a default audio track set, a line under the stream key tells you which one. See Default audio track below.
Recommended encoder settings
Expand Recommended encoder settings under the stream key. It holds the settings we recommend you configure in your encoder.
| Setting | Recommended |
|---|---|
| Video resolution | 720p or 1080p |
| Video bitrate | 3 Mbps for 720p, 5 Mbps for 1080p |
| Rate control | CBR, constant bitrate |
| Codec | H.264, Level 4.1 or 4.2 |
| Profile | High or main |
| Aspect ratio | 16:9 |
| Framerate | 25p, 30p, 50p, 60p |
| Keyframe interval | 1 or 2 seconds |
| Audio codec | AAC |
| Audio sample rate | 48 kHz |
| Audio bitrate | 120 Kbps or higher, and no more than 320 Kbps |
Two of the rows carry reasoning worth reading.
- Video bitrate. The bitrate you send in is distributed as the highest ladder option for viewers without transcoding. The quality you send is therefore the best quality any viewer can get, and sending a weak stream cannot be repaired further down the line.
- Rate control. Constant bitrate keeps your upload stable and gives the transcoder a clean source, which is why it is recommended for every live stream.
The video bitrate row also shows an Account max figure. That figure comes from your own account, so read it in the admin rather than working from the numbers in the table. Do not send more than it.
Re-streaming to other platforms
Expand Re-streaming to other platforms to forward the same live stream to another RTMP destination, such as a social platform, at the same time as it plays on your event site.
Click New stream target and fill in three fields:
- Name is a friendly name so you can tell targets apart, for example John’s Youtube channel.
- Target RTMP(S) host is the destination server. It has to start with
rtmp://orrtmps://. You find it in the settings of the destination platform. - Stream key is the key that destination gives you. It sits in the same settings as the host.
Click Add to save the target. Each saved target then gets an Enabled toggle, so you can turn a target off without deleting it, and a Delete button. A saved target also shows its state next to the toggle: Disabled when the toggle is off, and Waiting, Streaming or Error once it is on.
Both the host and the stream key come from the destination platform, not from here. If a target sits at Error, check them there first.
Advanced playback settings
Advanced playback settings control how the video player behaves for your viewers: the highest quality it may pick on its own, whether it matches quality to the player size on screen, how far ahead it buffers, and which audio track it starts with.
The defaults suit almost every event. Expand Advanced playback settings at the bottom of the page. The settings shown belong to the live channel currently selected for the event, so select the channel first.
These settings belong to the live channel, not the event. On a shared channel they apply to every event using it, past and future. Lower the quality for one demanding webinar and forget to restore it, and every later event on that channel streams lower too.
To get settings that apply to one event only, create an event specific live channel first, as described in Shared channels and event specific channels above.
Save player settings inside the section is the only thing that stores these changes. The ordinary event save does not include them.
When it is worth changing them
Rarely. The defaults let the player adapt to each viewer’s connection, which beats anything set by hand for an audience spread across home connections, offices, mobile and different devices.
The case that justifies a change is a large audience watching from inside one constrained network, such as an all-hands where hundreds of people in one office watch over a single internet connection. There, every viewer pulling the highest quality can saturate the link for the whole building.
Two alternatives to weigh first:
- Peer-to-peer delivery solves the same problem without lowering quality, by letting viewers on one network share the stream. The network team’s companion guide is Network requirements for peer-to-peer delivery.
- If viewers cannot reach the stream at all, that is a firewall or proxy question. See the Firewall & VPN configuration guide.
The section holds five settings, described below in the order they appear in it. Some are hidden depending on the channel, so you may not see all five.
Live channel name
Renames the channel. The name is used only in Event Admin, to tell channels apart in the selector, and is never shown to viewers. It appears only for shared channels, because event specific channels are named after their event. Renaming changes nothing about playback.
Max automatically selectable quality
The highest quality the player may switch up to by itself. Source / original applies no limit and is the default. The list appears only on channels carrying several quality versions.
Each option shows a resolution and an approximate bitrate, and a line underneath lists the versions your selected channel actually carries. Read the figures there. They differ per channel, and they approximate what the encoder produces. A saved value matching none of the current options is kept as a custom limit.
It is a hard ceiling, so a viewer on a fast connection and a large screen gets the capped quality too.
Limit quality to player size
The player never loads a resolution higher than the on-screen player can show. The admin describes this as one of the most effective ways to cut bandwidth, and it matters most for a small embedded player, where a full-resolution stream would be downloaded and then scaled down.
Separate Desktop and Mobile toggles. The recommendation, and the default for a new channel, is off on desktop and on for mobile. Unlike a quality limit this sets no fixed ceiling, so a viewer who goes full screen gets the quality that size deserves. The toggles are hidden on audio-only channels.
Player buffer (seconds)
How far ahead the player loads the stream, which sets the live delay. A smaller buffer shortens the delay but leaves less margin before a brief network problem stalls playback. A larger one is steadier and further behind. There is also a ceiling. A live stream keeps only a limited amount of recent video available, and buffering past that changes nothing.
Both numbers depend on the channel, so let the hint under the field tell you. It gives the recommended minimum and default, and where it applies, the point past which a larger value has no effect. Values are kept within 1 to 120 seconds. For a longer delay than that, contact support. It is a property of the channel, not a player setting.
Default audio track
Which track the player starts with on a channel carrying more than one, either several language tracks or real-time subtitles with AI voice-overs. The field is greyed out on single-track channels.
Leave it empty and the player chooses by the viewer’s browser language, picking an AI voice-over when one matches. That is usually what you want. Fill it in when everyone should start on the same track regardless of their browser, such as the floor language of a multilingual event. Enter the track as it is named on the stream, normally a language code; capitalisation does not matter.
The same setting appears as a dropdown on the Real-time subtitles page. It is one channel setting in both places, so changing it in one changes it in the other. See How to use Real-time Subtitles.
The “Playback quality is limited” notice
This yellow notice on the External encoder page appears whenever the selected channel has Max automatically selectable quality set to anything other than Source / original. Its link jumps to this section, which also opens by itself.
It is a reminder, not an error. Nothing is broken. The point is that a limit set weeks ago for a different event on a shared channel stays in force until someone changes it. To clear it, set the quality back to Source / original and press Save player settings, remembering that on a shared channel this affects every other event too.
The notice looks only at the quality limit. The Limit quality to player size toggles never trigger it.
Who can change these settings
Any user with access to the event, not only account admins. The people who produce events often are not administrators, and the default audio track in particular belongs with the event’s languages. Settings can only be changed through an event that uses the channel, and an event specific channel only from the event it was created for.
Going live
The channel is set up and your encoder is pushing to the server URL and stream key. Nothing reaches your viewers yet. Publishing the stream happens in the Live control room, and there is a link to it at the top of the External encoder page.
See How to control live event with Live control room for going live, recording, and controlling slides, chat and polls while you stream.
Related articles
- Live streaming overview covers the ways to go live and which to choose.
- How to control live event with Live control room covers running the stream once the channel is set up.
- How to use Real-time Subtitles covers subtitles, translations and AI voice-overs.
If you are unsure whether a change suits your event, ask before the event rather than during it. Contact support_CWC@euronext.com.