Video - add captions

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My Media iconThis entry relates to Kaltura, the video platform in FLO, and how to add captions to a video you've already uploaded


Why use captions?

In addition to being an important requirement for accessibility, captions have been shown to be beneficial for the learning of all students.  

A study conducted by Oregon State University in 2015 found that "more than half of students are using closed captions in their educational videos at least sometimes" and that students who did not report having disabilities "use captions almost as frequently as those who did". The respondents in the study "expressed strong agreement that captions help [them] focus, retain information, and overcome poor audio", that captions were "helpful learning aids" and that they helped "students with comprehension, accuracy, engagement, and the retention of information transmitted in course videos." (Read more about the study in this Educause review article, or find the full study.)

You're able to add captions to all videos in Kaltura. However, if you're working with student who has a Disability Access Plan (DAP), you should seek advice from a Disability Advisor at Health Counselling and Disability Services to discuss the student's needs and whether particular captioning services or requirements are included in the student's DAP. 


Steps to request machine generated captions for a video

The Kaltura video platform in FLO allows you to to request machine generated captions. Once you make a request, the captions are added to your video within approximately 30 minutes. 

  1. Log into FLO. You can add captions to the uploaded video in either:
    • your My Media repository: in the FLO navigation bar across the top of screen, open the drop-down menu next to your name and profile picture, then click My Media
    • the topic Media Vault, if you have published it there: open the topic, click the Navigation menu, then open the Media Vault (you'll find it after all the topic modules). 

  2. From the list of media, find the video you want to have captioned. Click its title to open. 
    Open video to caption

  3. Under the video, click the Actions drop-down menu and select Captions Requests.
    Action dropdwon open with caption request selected

  4. From the drop-down menus, select Service> Machine and Language >English, then click Submit
    Select Machine and English and submit

  5. You'll see a notification that your request is pending.


  6. Wait for around 30 minutes for the machine-generated captions to appear. Unfortunately, you don't get a notification when they arrive so you should check back after half an hour. One way to know they've arrived is that on your My Media or Media Vault entries page, auto-generated tags will appear next to the video.


  7. Open and play the video to review the caption quality. You'll notice:
    •  the video dimensions have changed slightly to accommodate the caption text
    •  a CC icon is now shown on the player. Use it to toggle the captions on/off
    • Show transcript button appears under the video. Click it to display the entire caption transcript. As the video plays, the relevant section of text is highlighted. 

You can edit the captions to fix any inaccuracies – see below. 


Steps to edit machine generated captions

Once the captions been attached to your video, you should edit them for accuracy. At the moment the machine-generated captions have an accuracy rate of about 70%. 

The caption accuracy will vary depending on things like:

  • how often you use acronyms or slang
  • how much subject specific terminology or jargon you use
  • your accent (the AI is currently best with American accents. If you have an Australian accent, you may find it struggles with the letter R)

  1. Open the video from your list of media entries in My Media or the topic Media Vault, by clicking its title to open. 

  2. Under the video, click the Actions drop-down menu and select Captions Requests.
    Actions dropdownwith captions requests selected

  3. You'll see your caption request with a status of Completed. Click the Edit icon (pencil) to open the caption editor.
    click the pencil icon

  4. The Closed Captions Editor opens, and from here you'll have the options here to adjust the caption text in a couple of different ways. 
    Closed Captions editor interface

  5. You can simply click a caption to open the text box, and type in / delete text as necessary. When you're finished within each caption textbox, just click away from it to close it.
    editing caption text

  6. There's also a very handy Search and Replace feature that lets you correct multiple transcription errors quickly, much like the one in Word. If the caption text repeatedly has error for the same word (eg as in the examples below where FLO was always transcribed as flow, and invigilation was always transcribed as visualization), then enter the wrongly-transcribed word in the Search in Captions field, enter the correct word in the Replace with field, then click Replace. It'll change them all.
    Search and replace fields empty
     examples:
    search and replace tool

  7. When you've finished editing, click Save then Yes when prompted to confirm.
    Save caption edits  Confirm save caption edits

  8. If you've finished editing the captions and are ready to return to the video, click Back in the top right of screen.
    Back button


Steps to delete a caption file

If you want to delete the entire caption file from a video, you can do this but be aware that you cannot recover or re-order those captions once deleted. Depending on why you're deleting the captions, it may be a good idea to download and keep a copy of the file, in case you want to re-upload them in future. 

To download the caption file (in case of future use)

  1. Open the video from your list of media entries in My Media or the topic Media Vault, by clicking its title to open. 
  2. Under the video, click the Actions drop-down menu and select Edit.
  3. Open the Captions tab. You'll see the captions file listed. To the right, there's a series of Action icons. Click the download icon
    download v ideo captions

  4. The caption file downloads in .srt format. Save it somewhere with your teaching resources in case you need it for future use. 

Note: if you want to delete immediately after downloading, skip to step 3 below. 


To delete the caption file

  1. Open the video from the My Media or the topic Media Vault  by clicking its title.
  2. From the Actions drop-down menu, click Edit.
  3. Open the Captions tab. You'll see the captions file listed. In the Action icons section, click Delete (cross icon).
    delete captions

  4. On the confirmation pop-up, click Delete to confirm. 
    confirm delete captions

  5. The file will be removed from the Captions tab. 


What to do if you've deleted the caption track and need to reinstate it

If you accidentally delete the caption track, at the moment you cannot reorder the machine generated captions within the tool. 

If you go back into the Captions Request section (via the Actions drop-down menu), you'll still see the previous caption order you submitted. Although the request is listed here, you can't recover the captions. This listing is now simply a record of the request and you'll notice that the status indicator next to Completed is red, not green. If you try to re-order the caption track, you'll see this error message:

error message for reordering captions


You now have two options if you need to reinstate the caption file:

  • If you didn't download a copy of the captions file prior to deleting it, you'll need to re-upload the video using the replace  video tool , then order the captions for the newly uploaded version (as per the steps above).

  • If you downloaded and saved a copy of the original captions .srt file before deleting, you can just re-upload this in Captions Tab in Edit mode.
  1. Open the video from your list of entries in My Media or the topic Media Vault by clicking its title.
  2. From the Actions drop-down menu, click Edit.
  3. Click the Captions tab then click Upload captions file.
    click upload captions file

  4. Follow the prompts in the pop-up window to browse and find the saved .srt file on your computer and upload it, select the language and save.
    upload prompts for caption file

  5. You'll see the captions file listed in the Captions tab, and it'll be added back in to the video. Note: You cannot edit these captions via the Caption Editor.
    captions uploaded

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