In preparation for the next Student Hub Live event, Karen Foley asked me to look into the options available for Closed Captioning, here’s what I found out…
Closed Captioning (CC) is a process for including text captions within a video or audio clip. The captioning can either be done automatically (by machine), manually (e.g. by a stenographer) or through some combination of the two. YouTube currently provides an automated service for generating closed captions in videos on their platform (try out the CC button for yourself). Interestingly, there is also an option to download the closed caption file for your own videos, edit it using a text editor and then upload the corrected version. For pre-recorded videos this seems to be a good option, although there are also commercial companies that provide a similar service at pretty competitive rates (e.g. $1 per minute).
Things are a little different for live broadcasts, here the automatic services are not always accurate enough, so closed captioning software is used to send the captions typed live by someone at the event (or on Skype) to the broadcasting service as a data stream, the captioning is then embedded in the video broadcast. LiveStream, You Tube Live and Wowser all ingest captioning data and then embed it within the broadcast. Most browser-based video players detect the caption data and then include a CC (Closed Caption) button for viewers to switch on and off the visible captions. As with pre-recorded videos, there are commercial companies that offer a live captioning service (sometimes referred to as STT – Speech to Text Service).
Here are a few links to the information I found – I havn’t used these directly, but I’d be keen to try them out.
- You Tube captioining (video) – Enabling captioning using YouTube speech recognition
- Example commercial captioining service – https://www.rev.com/caption
- Embedding live captions into a video stream
- LiveStream – How to enable Closed Captioning in LiveStream Studio
- You Tube Live – Live caption requirements
- Wowser – Closed Captioning for Adaptive Bitrate Streaming
- Closed captioning software applications (c/o You Tube Help page)
- Example commercial live captioning service: http://stagetext.co.uk/
- Wired Watershed’s post blogpost – Accessibility: How to live stream subtitles, and MORE…
