CaptionKeeper FAQS

Q: Does your technology require a specific line-21 decoder? Does NCAM sell the hardware, who do you recommend? A: CaptionKeeper requires line-21 closed-caption data as input. Currently the only input method is via the serial port. Several manufacturers sell line-21 data-recovery hardware. The one we've been using for development is the DE-241-DR made by EEG Enterprises ( Other manufacturers include Norpak (, Link Electronics ( As more products become available and we are able to test, we'll add to the list and post it at the website.
*Note that WGBH / NCAM doesn't sell the hardware, we just license the software.

Q: What are the hardware costs? A: Hardware costs vary.  The EEG DE-241-DR lists for around $950.  If you happen to already have a line-21 *encoder*, then the data recovery capability is generally built in already, but encoders tend to be quite pricey, in the $3,000-5,000 range.  Note that WGBH / NCAM doesn't sell the hardware, we just license the software. 

Q: Can one decoder feed multiple encoders? A: No, in the current version of CaptionKeeper, only a single video encoder of any particular type (RealServer, Windows Media Encoder) is supported.  You can simultaneously feed a RealServer and a Windows Media Encoder, but you you cannot simultaneously feed two RealServers.  We expect to offer multiple encoder support in a later version.

Q: What does the license cost? A: Licensing fees vary based on the size of the organization. Non-profit discounts are available. Please contact for pricing information.

Q: Does CaptionKeeper support digitizing cards? A: No, CaptionKeeper does not currently support any digitizing cards for caption input, it only supports external serial devices like the EEG data recovery box.  We recognize that support for digitizing cards is a desired feature, and we may support it in the future.  There are a couple of digitizing cards that we've peeked at, including the Osprey family, and the Digital Rapids family.  Both of these cards offer rudimentary (at best) line-21 extraction in their respective API, and we may support them in future releases.  As a side note, we find that digitizing board manufacturers come and go with some regularity, so building in support for each idiosyncratic board is costly wth limited shelf life.  Contrast this to line-21 manufacturers and their hardware, which has been around since the early 1980s.

Q: Is there a demo available? A: We are not currently running a 24-7 online demo of the real-time capabilities of CaptionKeeper. Feel free to contact us to set up an online demo.

Q: Can this software take output from a stenographer? A: Yes, CaptionKeeper can take live input directly from a stenocaption computer, as long as it can be routed to a serial port on the computer running CaptionKeeper.  If the stenocaptioning software is closed caption / line-21 enabled, then it will create output in line-21 data format.  For stenography packages that are not outfitted with closed caption / line-21 modules, CaptionKeeper has an input module which responds to normal ASCII text.  The steno software should be set to wrap lines at 32 columns, so that the output will mimic closed caption displays.

Q: Once the files are archived how do I attach them to my media? A: If you're capturing captions to files for archiving and on-demand display, they need to be integrated into their particular rich media environments.  For example, a RealText file is integrated with RealVideo or RealAudio files by using a SMIL file as a wrapper.  SAMI files can be integrated with Windows Media files using ASX files.  QTtext files are integrated in a number of ways, including SMIL wrappers or by using the QTtext file to create a text track placed directly inside the QuickTime file. 

For more information on integration of captions with the various players, go to:

There, you'll find in-depth information about multimedia caption integration.

Q: What if I already digitized my content? A: You can use CaptionKeeper to add the captions to your digitized video. You do not need to redigitize, just play the program out again, running the video through a line-21 data recovery decoder. CaptionKeeper will capture the timecoded text file in the format of choice. Offset the timecodes to line up the text and audio and you are done.

Q:Really like your website. Who designed and coded it? A: The CaptionKeeper website was a donation from freelance designer Eric Sagalyn. You can learn more about him and his services at his website,


©2004-2005 WGBH Educational Foundation. All rights reserved. CAPTIONKEEPER is a trademark of WGBH.