Broadcasts¶

A broadcast in Agora is one transmission: an all-hands, a webinar, a training session, a round-the-clock internal channel. In the panel broadcasts live in the Streams section.

The list of broadcasts

A broadcast is created in advance, not at the moment the camera is switched on: it has a name, a source, encoding parameters and viewing rights, and all of that is prepared before the meeting. The presenter is left with turning the encoder on.

The list¶

The columns answer the questions of whoever is on duty without making them open the card:

Stream name — the broadcast is addressed by it everywhere, the viewer's link included.
Sources and Status — two different lights. The first is about whether the signal arrived, the second about whether the broadcast is running. They do diverge: a source can be alive while the broadcast is stopped, and the other way round.
Template — which template the broadcast inherited its settings from.
Transcoder, Input resolution, Input bitrate — what arrived and what it turns into.
DVR — whether the archive is being recorded.
Viewers — how many people are watching right now.

The New stream name field and the Create button create a broadcast right there, from the list.

The source¶

The source is where the signal comes from. It is picked by protocol in the source row on the Sources tab; which protocols make sense depends on what the equipment can send:

SRT — the usual choice for a studio encoder and for a presenter in another city: the protocol survives network loss.
RTMP — what desktop capture software and most software encoders send.
MPEG-TS — intake from broadcast equipment.
RTSP — a camera in a meeting room.
Synthetic — the built-in generator: it proves that delivery and playback work before the studio is connected at all.

Input failover¶

A broadcast may have several sources, and their order in the list is the order of preference. The server runs the broadcast from the first live one: when the signal goes, it moves to the next; when it comes back, it returns.

That is what a second source is for: a meeting has no second take. The typical pair for corporate broadcasting is the main encoder in the studio and a spare on the presenter's laptop.

The Placeholder on source loss row says what to show a viewer when no live source is left. Without it the viewer sees a black screen and cannot tell whether the fault is theirs or yours.

The transcoder¶

The same broadcast is watched from an office laptop and from a phone over VPN. The transcoder makes several variants out of the input — a ladder — and the player takes the one the viewer's link can carry.

The Standard ladder 1080/720/360 + AAC preset covers the ordinary case with one press. Individual rungs are configured in the same place when a set of your own is needed.

Transcoding is the heaviest work in the installation, and it is computed on the server the broadcast runs on. That is worth remembering when planning how many meetings run at once.

The card's tabs¶

Basic settings — the name, the template, whether it is enabled, the built-in player and the "what came in, what goes out" summary.
Sources — the sources, their health and their timeouts.
Transcoder — the ladder.
Processing — subtitles, teletext, thumbnails.
DVR — the archive.
Egress — sending the broadcast out, and SRT publishing.
Layout — where the broadcast is placed, see Stream placement.
Sessions — who is watching this particular broadcast.
Output history — how the broadcast was served earlier.