Can we deliver closed captioning with our media files?

The LightcastCDN delivers closed captioning data provided by clients. You can upload your closed captions within each video upload or video edit page.
For video files uploaded through the FTP uploader instead of the Web Uploader: you can upload the closed caption files by going to the video editing page of each uploaded video once the transcoding process is completed. 

To open the video edit page, go to Video Archive and click on the video you would like to upload closed captions for. Switch to "Metadata" - there you can upload a subtitle file under "Subtitles", at the bottom of the page.