Please note that the moderator dashboard needs to be opened on a computer with a built-in camera.

What is RTMP?

RTMP stands for Real-Time Messaging Protocol and is a communication protocol for streaming audio, video and data over the internet. RTMP allows low-latency streaming, meaning little time between the moment the video is captured and the moment it is displayed to the viewer.

Why use RTMP?

When connecting a camera and microphone input to the moderator dashboard, viewers won't see anything anymore whenever the moderator dashboard gets disconnected to the internet for some reason. When connecting an RTMP stream through the moderator dashboard, this stream is pushed directly to the viewers. This means the connection of the moderator does not influence what is delivered to the viewer.

Besides that, you can edit the stream before you share it with viewers, for example:

  • combine a video of the slides with that of the speaker into one video;

  • add images or text, on top of the video, such as the event logo or speaker name;

  • add transitions between different videos.

Video specifications and limitations

All video input, including RTMP, is compressed before it's delivered to attendees to make sure that also those with less bandwidth can follow the session smoothly. These video specifications can be found in another article.

Please note that though RTMP was designed for low-latency streaming, you can still experience delay, which may vary from 1 to up to 30 seconds.

There are a few limitations to using RTMP. Because of the delay, it is not possible to use screen sharing along with RTMP, as it is very likely that those will be out of sync. For the same reason, the RTMP stream is ignored when the moderated session is in Panel mode. Also, the session recording will only record the audio coming from the RTMP stream if that is the active speaker. Other speakers and moderators will not be recorded.

Recommended settings

  • FPS: 30 FPS

  • Video Bitrate: 2000 kbps

  • Audio frequency: 48 KHz

  • Audio bitrate: 128 Kbps

  • Audio: stereo sound

Connect your RTMP stream

1. Install OBS

To test RTMP, you will need to set up a third-party streaming application. OBS (Open Broadcaster Software) is a popular tool for this. Install this tool and open it.

2. Invite a moderator

First, on the page Virtual & Interactivity, tab Virtual room invites and recordings, find the session you want to use RTMP in. Open it, set it to Moderated session, and invite a Virtual room moderator.

3 .Get the RTMP stream properties from the moderator dashboard

From the invite you received, open the moderator dashboard. From this dashboard, you will choose the RTMP as input source, instead of a video and audio device.

At the bottom of the screen, next to the camera and microphone icon, click the small arrow and select RTMP stream.

Click Copy next to RTMP URL.

In OBS, go to Settings bottom right, and then choose Stream from the left menu.

Below Service, choose Custom... Now paste the URL you just copied below Server. Go back to your moderator dashboard and copy the stream key. Paste it in OBS below Stream Key. Click OK to save your changes.

4. Set up video and audio source

Default, OBS will have a Mic/Aux input, but if you use that, the sound will be very distant. You will need to mute it, and instead add your audio input device.

Furthermore, no video device is available by default, so you'll have to add one too.

To set up a video and audio source, go to the bottom section, and click the + below Sources.

Select Audio Input Capture to add a microphone.

In the modal that opens, click Create new.

Next, select the device you want to use.

Repeat these steps for Video Capture Device.

You have now set up a stream.

5. Start streaming

In OBS, click Start streaming from the panel bottom right.

You are now streaming to the moderator dashboard. To live stream to the audience, take the following steps:

  1. In the Live Speaker list on the right side, select yourself as the Presenting Speaker by clicking the computer icon that appears when hovering over the person’s name. A red tag ‘Presenting’ is shown above the active speaker. Your RTMP stream will appear in the speaker frame on your dashboard.

  2. You can control whether the room is open or closed in the bottom-left corner. Attendees can only access a virtual room when it is open. We advise opening a virtual room 10-15 minutes before the session starts. This is the equivalent of allowing people some time to come into a physical room where the session takes place so that they can get settled.

    If a room has been opened but the session is not broadcasting yet, the attendees in the virtual room cannot see or hear your live stream yet.

  3. You can control when the session is broadcasting or not using the broadcast button in the bottom-left corner. This button only appears once the room is opened. When broadcasting starts, attendees will be able to see your live stream. When the session is broadcasting, it is recorded automatically, a Live tag is shown in the slides and speaker frame, and a timer starts running in the lower-left corner.

6. Stop streaming

To stop streaming to viewers, you can do the following things:

  • Choose Stop streaming from OBS

  • Deselect the moderator with RTMP as active speaker on the dashboard, so that there's no longer an active speaker.

  • Select another speaker or moderator as active speaker.

Use RTMP together with Vote

At this moment, we are working on making Vote available from the moderator dashboard.

Please pay attention that due to the delay, you should not start the vote directly when after you announce it, as the Vote will be immediately visible. Since the delay may vary, please check in advance how long you would have to wait before starting the vote.

In the the moderator dashboard itself, you will see what the attendees see so you should be able to start Vote at the correct moment: after the speaker has announced the vote but is no longer talking.

Panel mode

Due to the delay on the RTMP stream, it cannot be used in panel mode. To allow discussion between virtual and on-site speakers, there are two options:

  1. Use video/audio source to broadcast on-site instead of RTMP.

  2. Have virtual speakers dial in through an external tool (f.e. Zoom) and include the entire discussion in the RTMP stream.

RTMP and Vimeo / YouTube

If you are broadcasting through RTMP on YouTube or Vimeo, you can add those video links on the platform. The Vimeo or YouTube URLs can be added to session banners, in news messages, or to the web app's landing page.

  • For more information about RMTP on Vimeo, click here.

  • For more information about RTMP on Youtube, click here.

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