Subtitles in the Asset Manager: Editing and AI Generation

Subtitles make your videos and audio files easier to follow, accessible to more learners, and usable in other languages. In the Asset Manager you can add subtitles to any video or audio file. You can upload your own subtitle file, let AI generate subtitles for you, and fine-tune the text and timing in the built-in subtitle editor.

This article covers:

Where to find subtitles
Uploading a subtitle file
Generating subtitles with AI for one file
Generating subtitles with AI for many files at once
Editing subtitle text and timing
Managing your subtitle tracks

Where to Find Subtitles

Open a video or audio file in the Asset Manager to see its details. You'll find the Subtitles section there. It shows every subtitle track the file already has, plus a counter with the total number.

Each track in the list shows:

A flag and the track name. If the track has no name, you see the language instead.
The file name (for uploaded tracks only)
An AI badge if the track was generated with AI, or an upload icon if you uploaded it yourself
Action buttons: download, edit, edit text and delete

If a file has more than six tracks, only the first six are shown. Click Show all to see the rest, and Show fewer to collapse the list again.

Good to know: Each language can only be used once per file. Languages a file already has subtitles for are greyed out when you add a new track.

Adding a Subtitle

Click Add subtitle below the list. A panel opens with two tabs:

Generate with AI: AI listens to the audio and writes the subtitles for you
Upload file: you add a subtitle file you already have

You only see the Generate with AI tab if AI subtitle generation is turned on for your organisation.

Uploading a Subtitle File

Click Add subtitle and pick the Upload file tab.
Choose your subtitle file. Only WebVTT files (.vtt) are supported.
Enter a Subtitle name. Learners see this name in the player's subtitle menu.
Choose the Language code from the list. You can search the list.
Click Save.

If something is missing or wrong, you see a message right below the fields. For example, the file may be empty or have the wrong file type, or the name may be missing.

Generating Subtitles with AI (One File)

Click Add subtitle and pick the Generate with AI tab.
You don't need to set a Source language. The AI detects the spoken language from the audio.
Under Select target language, choose the language you want the subtitles in. It can be the spoken language or a different one. The AI translates for you.
Click Generate subtitles.

Generation usually takes about a minute. You can keep working in the meantime. The new track shows Generating... in the list while it's being created and is ready to use as soon as it finishes.

AI tracks are automatically named after the word for "On" in the subtitle language, for example "On" for English or "An" for German. That's what learners see in the player's subtitle menu. You can rename the track at any time (see "Managing Your Subtitle Tracks").

Generating Subtitles for Many Files at Once

Have a whole course worth of videos? You can subtitle many files in one go.

Where to Start

The Generate subtitles with AI button appears in the Asset Manager toolbar:

When you select files and/or folders. Only video and audio files are subtitled. Selected folders include all their subfolders.
When you have nothing selected and the folder you're in contains video or audio files or subfolders. The whole folder and all its subfolders are then included.

The button isn't available in search results.

Settings

Subtitle language: The language the subtitles are written in.
Track name: Learners see this in the player's subtitle menu. It's filled in for you based on the language, and you can change it.
Lines per subtitle: One line or Two lines (default).
Max. characters per line: How long a single line can get, between 20 and 80. The default is 42.

The Asset Manager remembers your line settings for next time.

Before You Start

Once you pick a language, the dialog checks your files and tells you how many will get subtitles. Click Show files to see the list.

Some files may be skipped, and the dialog tells you why:

They already have subtitles in this language
They're already being subtitled
They aren't video or audio files
You don't have access to them
They no longer exist

There's a limit on how many files you can process at once. If you select too many, you'll see how many you've chosen and what the maximum is. Split your selection into smaller batches in that case.

Click Generate subtitles to start.

Following the Progress

Once started, a progress indicator appears in the toolbar (for example "Subtitles 3 of 12"). Click it to see each file and its status:

Waiting: in the queue
Generating…: in progress
Done: finished
Failed: something went wrong with this file
Skipped: left out
Stopped: cancelled

Click Stop to cancel the rest of the batch. Files that are already done keep their subtitles.

You'll get a notification when the batch is finished. It also tells you if some files failed. If too many files fail, the batch stops on its own. The batch keeps running even if you close the Asset Manager or reload the page, and the progress indicator comes back when you return.

Editing Subtitle Text and Timing

AI-generated subtitles are usually very good, but names, technical terms or timing may need a touch-up. Click the Edit text button on a track to open the subtitle editor. You can't edit a track while it's still being generated.

The Editor at a Glance

A player at the top plays your video or audio with the subtitles you're editing. You see your changes right away, even before you save.
The List tab shows each subtitle as its own row with its time, speaker and text.
The WebVTT tab shows the whole subtitle file as plain text, for advanced editing.
A summary at the bottom shows how many errors and warnings there are.

Working in the List

Click a row to select it. The player jumps to that spot. While the media plays, the current subtitle is highlighted and the list scrolls along.

When a row is selected, you can change:

Text: what learners read
Start and End: when the subtitle appears and disappears. Click Start at current time or End at current time to use the player's current position. That's the easiest way to get the timing right.
Speaker: who is speaking (see below)

The buttons next to the selected row:

Play this subtitle: plays just this section and stops at its end
Add subtitle after: adds a new two-second subtitle right after this one
Split: splits the subtitle in two. It splits where your cursor is in the text. If your cursor isn't in the text, it splits near the middle.
Delete: removes the subtitle

If a track is empty, you'll see No subtitles yet and can add the first subtitle from there.

Speakers

If your track has speakers (for example in an interview), each row shows who is talking.

To change the speaker for one subtitle, type or pick a name in the Speaker field and press Enter. Leave it empty for No speaker.
To rename a speaker everywhere at once, use the Speakers bar. For example, you can change "Speaker 1" to "Anna" in all subtitles in one step.

Subtitles with several speakers can only be edited in the WebVTT tab. That way their text doesn't get mixed up.

Errors and Warnings

The editor checks your subtitles as you work. Rows with problems get an icon.

Errors (red) must be fixed before you can save:

The time is invalid (use the format HH:MM:SS.mmm)
The end comes before the start
The text is empty
A speaker tag has no name

Warnings (orange) don't stop you from saving, but you should take a look:

A subtitle overlaps the previous one
A subtitle starts before the previous one
A subtitle starts after the media has ended

Saving

Click Save to keep your changes. Save is only available once you've changed something and there are no errors. If you close the editor with unsaved changes, it asks if you want to Discard them or Keep editing.

Managing Your Subtitle Tracks

Each track in the list has these buttons:

Download: saves the subtitle as a .vtt file to your computer
Edit: changes the track's settings. For uploaded tracks you can replace the file and change the name and language. For AI tracks you can change the name only.
Edit text: opens the subtitle editor (see above)
Delete: removes the track after you confirm

Step-by-Step Guides

Subtitle a video in its own language and fix the names

Open the video and click Add subtitle.
Choose Generate with AI, set the target language to the spoken language and click Generate subtitles.
Wait about a minute until the track is ready.
Click Edit text. Play the video and check the subtitles.
Use the Speakers bar to replace "Speaker 1" and "Speaker 2" with real names.
Correct any misspelled terms in the Text field and click Save.

Offer a video in several languages

Open the video and click Add subtitle.
Generate an AI track in the first language.
Click Add subtitle again and pick the next language. Languages the video already has are greyed out.
Repeat for each language. Learners can switch languages in the player's subtitle menu.

Subtitle a whole course folder

Open the folder that holds your course videos. Don't select anything.
Click Generate subtitles with AI in the toolbar.
Pick the Subtitle language. Check the Track name and line settings.
Look at the file count, and click Show files if you want to check the list.
Click Generate subtitles and keep working. You'll get a notification when it's done.

Fix subtitles that appear too early or too late

Click Edit text on the track.
Select the subtitle and click Play this subtitle.
Play the media and pause where the sentence actually starts. Click Start at current time.
Pause where it ends and click End at current time.
If you see a warning about an overlap, adjust the neighbouring subtitle the same way. Then click Save.

Make long subtitles easier to read

Before generating (batch): Choose One line, or lower Max. characters per line. Shorter subtitles are easier to read on small screens.
After generating: Select a long subtitle in the editor, put your cursor where the sentence naturally breaks and click Split. Then fine-tune the start and end of both halves.