You can easily create and upload caption files when you record a new video or upload an existing video in Canvas using the Rich Content Editor. The Rich Content Editor is used in features that support the editor (Announcements, Assignments, Discussions, Pages, and Quizzes).
You can create a caption file using an external captioning tool such as Amara or YouTube.
Note: Users can view video captions in the Canvas apps. However, iOS devices can only display captions in WebVTT format. If you use another format besides WebVTT, users on iOS devices will not be able to display the video captions.
When you add captions to a media file, the file displays a CC icon.