External encoder
Last updated: September 30, 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 gives the event its own stream key, so do it before you configure your encoder.
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. Two are enabled for most accounts.
| Channel type | What it creates |
|---|---|
| 1080p video, 10s delay | A channel for a 1080p video stream, with 10 seconds of delay |
| Audio, 10s delay | A channel for an audio only stream, with 10 seconds of delay |
Pick the audio type for an audio event and the video type for a video event. The delay in the name is the live delay the channel is built for.
Other types exist, including longer delays, 720p and single bitrate. Contact support if you need one.
If the channel type and the event type do not match, the page shows a red warning with a link to Build → Videoplayer set up, where the event type is set. Web studio events take the right channel into use by themselves.
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. They follow the channel you selected above, so if you change the channel later, copy both again.
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 rows are worth reading twice.
- 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.
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.
Only the stream you send in over RTMP, or produce in web studio, is re-streamed. Slides are not included.
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
These settings control how the player behaves for your viewers. The defaults suit almost every event. Changes are saved with Save player settings, not with the event’s own Save.
They belong to the live channel, not the event. On a shared channel they apply to every event using it, past and future, so a limit set for one webinar stays until someone clears it. For settings that apply to one event only, use an event specific live channel, described above.
Live channel name
Names the channel. The name is visible only in Event Admin, never to viewers. Shown for shared channels only, since event specific channels are named after their event.
Max automatically selectable quality
The highest quality the player may switch up to by itself. Source / original means no limit. It is a hard ceiling, so viewers on fast connections get the capped quality too.
The bitrates shown are approximate and specific to your channel. While a cap is set, the page shows a yellow notice as a reminder. Only shown on channels with several quality versions.
Limit quality to player size
The player never loads a resolution higher than the on-screen player can show, which saves the most bandwidth when the player is small. Separate Desktop and Mobile toggles, off on desktop and on for mobile by default. Hidden on audio-only channels.
Player buffer (seconds)
How far ahead the player loads the stream, which sets the live delay. A smaller buffer means less delay but stalls sooner on a network hiccup, and a larger one is steadier. The hint under the field gives the recommended value for your channel, and values beyond the stream’s playlist window have no effect.
The range is 1 to 120 seconds. For a longer delay, contact support.
Default audio track
Which track the player starts with on a channel that has more than one audio track. Left empty, the player picks by the viewer’s browser language and prefers an AI voice-over when one matches. Fill it in to start everyone on the same track, for example the floor language of a multilingual event. Use the track name as it appears on the stream, normally a language code.
The same setting is on the Real-time subtitles page. See How to use Real-time Subtitles.
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@videosync.fi.