Type out transcript (script) of your lecture video to easily type in captions in a video editor or upload them to Canvas.
You can type this out into any word processor, and then upload it into a video editor. 

You have the capability of adding captions to video's and audio recordings uploaded or recorded in the Rich Content Editor. You can find out more about captioning at this Canvas tutorial or HSU Screen Steps video upload resource.

YouTube does the difficult work of creating auto-synced captions. Be sure to check the accuracy! How to add subtitles and closed captions on YouTube.

You can use your transcript to check the accuracy and easily edit the captions in the caption editor within youtube. 

You can invite others to edit to get support from Academic Technology and your students in editing captions even providing subtitles in different languages!

• You will have to give permission to submitted caption changes after reviewing them. 

Contact Academic Technology to submit a request for captions for your videos or video's you've found online. The return time for the process can take up to a week, but this provides high-quality professional captions to your videos. 

• If your video is owned by you, you're captioned video will be returned to you with the captions burned into the file or with the caption file so you can upload the caption file into your video yourself using a video editor. 
• If the video source doesn't belong to you, the video will be returned to you with a Smart Player link.

Use this AST Caption Request Form  to request videos you need captioned.

You can add subtitles in Camtasia, but this will directly embed the text within the video. With this option, viewers won't have the capability to turn captions on or off. 

You can find out how to add captions and the importance of caption at this Camtasia tutorial guide.