Using the Alignment Tool to Caption Videos in Kaltura

The Kaltura Reach Alignment service is a free and easy way to add closed captions to videos by uploading a word-for-word transcript to Kaltura.


Step 1. Save the audio transcript of the video as a plain text (.txt) file.

When following best practices for creating narrated lecture presentations, a word-for-word script should be created either as a stand alone document and/or saved in the notes section of each slide of the narrated PowerPoint presentation.

Note: It is important to clean up the transcript to remove any slide headers, page numbers, or text that was part of the slide image.

  • Option 1: Use Adobe Acrobat to convert a PDF transcript file to plain text file

If the transcript is a PDF (such as a “Notes” page from a PowerPoint) you can open the PDF in Adobe Acrobat and then Export it as a plain text file.

  • Option 2: Use Microsoft Word to convert a .doc transcript file to plain text

Open the document and Save As .txt file, making sure to choose Unicode UTF8. An alternate method is to open the file from Word (if it is a PDF, it may take a minute to convert), use your keyboard shortcuts or the edit menu to select all, and then copy. In a new document, use the paste option to Keep Text Only. Save your file as a plain text file.


Step 2. Log in to and select a video

The Alignment service is only accessible in the Kaltura Media Service (KMS); the aligment service is not accessible via the KMC.

Note: Ordering ANY services in Kaltura requires editor rights to the video. It may be necessary to first access the video via the KMC and add your UserID as "editor". Be aware there may be a short period of time before the change is updated from the KMC to the KMS.


Step 3. Access the Alignment service

From the Actions menu on the selected video in Kaltura, select Caption and Enrich

Menu to select Caption and Enrich


Step 3. Select the Alignment feature

Under the heading “Order Captions & Enrichment Services,” you will select Machine and Alignment from their respective drop-down menus.

Menu to select Machine Service and Alignment Feature


Step 4. Upload the text file for alignment

Click on the Upload txt button.

Note: If the Upload file button is greyed out, wait until editing privileges to the video have been updated.

Menu to select Upload txt


Click the Select File button, select the plain text file of the transcript then Submit. Adding a title and description to your file is optional.

NOTE: Best practice is to add a title that matches the name of your presentation and a brief 1-2 sentence description. These details will be available to viewers in the "Attachments" section below the video player. Viewers will also have the option to download the transcript file. 

Menu to select the txt file


Step 5. Check the alignment of the closed captions to the audio of the video

After Kaltura has notified you that the video has been captioned, it is recommended that you “spot-check” the video’s beginning, middle, and end to make sure the captions are properly aligned to the audio in the video.



Article ID: 128201
Wed 2/17/21 2:33 PM
Mon 3/1/21 12:50 PM