How to manage a live event?
Event status
A Clevercast event has a certain status, which you can change on the event management page.
This allows you to hide the live stream from your viewers until the actual event begins. Unless the status is set to Started
, viewers will see a poster image (or message) in the embedded player. Additionally, the status also determines if you can start broadcasting and whether language rooms are available to interpreters (T@H) and subtitlers and correctors (captions). Finally, when an event starts, a cloud recording is also started.
Note: this also applies if you have a webinar plan. In that case, the embedded player is the player that participants see on the webinar page.
The event appearance tab lets you set a separate image (or message) for each status, or a single general image for all statuses. It also lets you set a countdown timer (until the scheduled start time of your event) to be displayed before your event. When the event is started, the timer automatically disappears.
The event status can be:
- Inactive: While the event status is
Inactive
, the embedded player displays the Preview image/message and (optionally) countdown timer. The event is not ready to receive a broadcast. - Preview: After setting the status to
Preview
, you can start broadcasting. On the event management page you can already see the live stream in the preview player, but it is not yet visible in the embedded player. Your viewers will keep seeing the Preview image/message. - Started: When you press the ‘Start event‘ button, the embedded player detects this and shows the live stream to your viewers (the Preview image/message automatically disappears).
- Paused: When you set the event status to
Paused
, Clevercast keeps processing the live stream but hides it from your viewers. You can continue to broadcast and see the live stream in the preview player, but your viewers can no longer see it in the embedded player. Clevercast automatically detects the status change and replaces the live stream with the Paused image/message. - Ended: When you set the event status to
Ended
, Clevercast stops processing the live stream. The player detects the status change and shows the Ended image/message instead of the live stream.
Event status and multilingual live streams
If your event includes remote interpretation, real-time correction of AI-generated closed captions and/or speech translations and/or real-time human subtitling, the language rooms (for interpreters, correctors and subtitlers) are only available when the event status is set to Preview
, Paused
or Started
. When the status is set to Inactive
or Ended
it is not possible to connect to the language rooms.
Event status and cloud recordings
A cloud recording is automatically started when you set the event status to Started
. When you change the status (to any other status), the cloud recording stops. When you start the event again, a new cloud recording is started.
Live stream latency
What is latency (delay) ?
It is important to realize that a live stream is always served with a certain delay, inherent to the technology and protocols involved. For one-to-many streaming, this is mainly to allow the video player to buffer a short part of the stream. To guarantee smooth streaming while bandwidth fluctuates, the video player uses the internal buffer while delivering streaming video.
The technical term for this is 'latency', which refers to the delay between when content is captured or generated and when it reaches the viewer. Several factors influence latency in HTTP Live Streaming (HLS):
- Segment Duration: HLS breaks the video into segments (typically 2–10 seconds). Lower segment durations can reduce latency, but too-short segments may increase buffering.
- Buffering: players buffer several segments to ensure smooth playback. The more segments buffered, the greater the latency.
- Playback Device: certain devices may add additional latency.
It is important to be aware of latency, as this has implications on the Event management flow (see below).
Latency in Clevercast
By default, Clevercast uses HTTP Live Streaming (HLS) with segments of 4 seconds. Due to player buffering this will result in a typical latency of about 16-18 seconds, but this may be higher on some connections and devices. In particular, iOS devices (iPhone, iPad) allow latency to grow to a maximum of 2 minutes. Any live stream (also live streams from YouTube, Facebook ...) can therefore have a delay of 2 minutes on these devices.
You can reduce the segment size to 2 seconds by setting your event to 'Low latency', which will result in a latency of 8-10 seconds. However, iOS devices will still allow latency to grow to a maximum of 2 minutes. Also, take into account that 'Low latency' results in the player doing less buffering, which may causes disruptions to viewers with a slow internet connection.
For AI events, Clevercast increases the latency to 60-120 seconds, to improve the accuracy and quality of AI-generated closed captions and/or speech translations. The exact delay depends on the settings of your event, e.g. the latency will be lower when not using real-time correction and speech translations.
Notes:
- Latency is also determined by your player settings: you can change these via player profiles. But to do this, you need to know how the HLS protocol works. If you don't, please contact us.
- Latency does not affect the synchronization of video and audio streams and closed captions. Clevercast automatically ensures that these always remain in-sync, regardless of latency.
- For certain features, latency is reduced to a few milliseconds (e.g. real-time transcription of closed captions for on-site use).
Event management flow
Because of latency, you should broadcast at least a couple of minutes in advance and wait a couple of minutes after your event has ended before pressing the End event button in Clevercast. We recommend the following:
- Before the start of the live action (at least 5 minutes in advance) set the event status to
Preview
and start broadcasting. - Use the Preview player to see whether the incoming stream is okay, including possible closed captions and/or audio translations. Your viewers won’t see the stream in the embedded player until you start the event. If you are using human interpreters, correctors or subtitlers, let them connect to their rooms and verify if their connection and equipment is okay.
- When the live action is about to start, press the Start event button. This will make the live stream visible to your participants. Do this at least two minutes before the live action starts. This allows the player to start buffering and ensures that nobody misses the start. It also ensures that the cloud recording is complete.
- When the live action ends, wait at least 2 minutes for a regular event, and 4 minutes for an AI event before pressing the End event button or Pause event button. When the embedded player detects that the event status is set to
Ended
, it will show a poster image or message instead of the live stream. If you set the event toEnded
immediately after the live action ends, some viewers may still be watching the stream (due to latency). Waiting for two minutes is necessary because of iOS devices, which allow HLS latency to grow to two minutes. In case of AI events, two extra minutes are necessary because of the increased latency.
If this is your first time using Clevercast, we highly recommend testing out this workflow beforehand.
Note: when you are done with an event, set its status to Inactive
or Ended
. This will stop it from using server resources. Don’t forget to turn off your encoder after a live stream has ended, otherwise you will be using extra live processing hours.