Yesterday’s Hangout On Air on American Sign Language (ASL) and Deaf culture is now a video on YouTube, and that video is being crowdsourced for subtitles at Amara. If you’ve never heard of Amara (I hadn’t until yesterday), it is a website dedicated to crowdsourcing the captioning of videos. How it works is that anyone can embed a video on Amara, and anyone can caption it on a volunteer basis. Captioning is very time-consuming. It involves both transcription, line division, and time coding. The average rate of speech is somewhere around 5 syllables per second (Kendall, 2009, p. 145). You have to listen to a few seconds of a video, pause the video, type what you just heard, and repeat the process. The transcription has to be time-coded; i.e., the words have to be matched with the time they appear on the video, usually at about 32 characters per line, so that’s time-consuming too. For these reasons, when it comes to help with closed-captioning, the more the merrier, especially because so many people make videos pro bono. This video is over 48 minutes, and of course it’s pro bono. If you would like to closed-caption a few lines of the video on Amara, please do. A little work by a lot of people will get the job done.
1. I don’t like to repeat statistics without sources, but 32 and 35 characters appeared often on webpages. Screen Subtitling’s white paper “Closed caption subtitling” [PDF] said “the number of characters per line or row is a set limitation” (Screen, 2008, p. 2) with no specification of the limit or reference to the authority. I searched the Internet for the “set limitation” on characters per line, and I found the same numbers repeated in different places with no traceable references. AutoCaption.com’s “Closed captioning defined” page said, “the features of traditional captioning are: … 32 characters per line” with no citation. Welstech wiki said the Department of Education required 35 characters per line, yet when I searched the US Department of Education website, I could find no such specification. CPC.com’s Closed Captioning FAQ answered the question, “What features are supported by CEA-608 closed captions for standard definition?” thus: ” […] A caption block can have up to 4 lines and up to 32 characters per line, although for accessibility reasons, it is recommended not to exceed 2 lines and 26 characters per line […].” I searched “CEA-608″ to find the source, and I found the Consumer Electronics Association (CEA) CEA-608-E Standard Details page. Unfortunately, the standards are published in a printed book that costs $300, $225 for members. Can anyone quote the source of authority? If so, please leave a comment.
Kendall, Tyler S. (2009). Speech rate, pause, and linguistic variation: An examination through the sociolinguistic archive and analysis project (Doctoral dissertation). Retrieved from
Screen. (July 2008). Closed caption subtitling. Retrieved from
- Amara/Universal Subtitles gets $1MM from Mozilla and the Knight Foundation to internationalize Web video (boingboing.net)
- You can now adjust the closed-captions on my YouTube vlogs (terptrans.com)
- Captions for all: more options for your viewing and reading pleasure (youtube-global.blogspot.com)