The lifecycle of a Timbra project – CaptionHub

A Timbra project moves through a series of stages, from the moment it's created on the dashboard to the point where captioning ends and any post-event exports are complete. This article walks through each stage and explains what to expect along the way.

1. Project creation

Create a new project from the Dashboard by selecting Create new project and choosing Live stream from HLS/RTMP/SRT. You can also import directly from a supported platform — for example, selecting Brightcove from the same menu will list your current live streams in Brightcove and allow you to import one.

Once created, the project is ready to be configured, but captioning has not yet started.

2. Configuration

Before your event starts, use the Languages & settings tab on the project page to configure captioning and translation. Key settings include:

Primary and fallback transcription services — choose your primary (and optionally fallback) speech recognition service using the Transcription service setting.

Translation languages — Timbra supports translation into 250+ languages via Amazon, DeepL, and Google.

Custom dictionaries and termbases — add speaker names, product names, and other domain-specific terms to improve transcription and translation quality.

Audio track — by default Timbra uses the first audio track in the HLS/SRT/RTMP stream; you can change the track (HLS) or PID (RTMP/SRT) in Edit project

Visibility mode — control who can see captions and the transcript, also under Advanced options.

3. Stream states

Stream status badges appear at the bottom of the event project thumbnail on the dashboard and let you identify the current state of a project at a glance.

The main statuses are:

New — the project has been created and is ready to configure.

Captioning — the event is live and captions are actively being generated.

Stopped — captioning was stopped manually, because of inactivity, or after running for 24 hours; the project can be restarted.

Ended — the source stream has ended and caption generation has stopped.

Source error — there is a problem with the incoming stream that is preventing Timbra from receiving it correctly.

Error — an issue was detected within the Timbra project itself. Open the project for more details.

Listening — for RTMP and SRT projects, Timbra is waiting for your encoder to connect. You can now start streaming.

4. Going live

Once your stream is active and you start captioning, the project moves to Captioning status. Timbra ingests the live stream and publishes captions in real time, synchronised with the audio.

For HLS-based projects, Timbra uses the stream's built-in buffer to produce captions just in time for viewers. For RTMP/SRT-based projects, audio and video are sent directly to Timbra.

During the event you can:

Mute captioning to prevent music or pre-event content from being transcribed.

Switch between transcription services manually using the Transcription service setting in Languages & settings if needed.

Control the project from a mobile device by logging in to CaptionHub and opening the project.

Control the project via the API for automated or integrated workflows.

5. Stopping captioning

Captioning can end in several ways:

Manually — you can stop captioning at any time from the project page. The project status changes to Stopped. You can restart captioning from a stopped project.

Automatically — projects stop automatically in any of these situations:

No audio is received for 60 minutes

For HLS projects, the stream ends (no new video segments appear for 60 seconds)

Captioning has been running for 24 hours (see Limits and quota)

When the source stream itself ends, the project status changes to Ended.

6. Post-event: export and reuse

After an event has finished, you can download a VTT subtitle file for every language from the History tab by clicking Download VTTs. These files are primarily intended for QA and auditing.