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Collection: Video and Captioning

purple arrow (1137 bytes) About Captioning Software

This resource provides basic information about hardware and software necessary for captioning in a school.

For information about applications of captioning for students who are deaf and hard-of-hearing and for students with learning disabilities, click here for the companion resource: Learning with Captioning.

For descriptions of available captioning software, click here for Captioning Software. The author of this resource, Mardi Loeterman, will be happy to provide more in-depth information about applications and equipment; her address is at the end of this resource.

What Equipment is Needed for Captioning?

A captioning workstation consists of a personal computer and monitor, two VCRs (one to play the video and the other to record video with captions-you cannot caption directly onto your original video) and color monitor, a character generator that superimposes text onto video, and captioning software. Actual equipment specifications vary, depending on the software used. Other useful equipment are a printer and a camcorder. If captions will be synchronized with timecode (see below for explanation), you will also need a timecode reader and your videotapes will need to have timecode.

In evaluating a potential captioning system for an educational setting, the most important features to keep in mind are:

  1. how well the word processing software suits the needs of the students or teachers who will be using it,

  2. the workstation's ability to use timecode (which automates the caption-recording process) and the school's potential need for such a feature, and

  3. the level of technical support available from the vendor and from the school.

What Skills are Needed for Captioning?

Word Processing: The core of a captioning system is the word processor. Some systems allow you to use your own word processor while others have a word processor built in. If the system is DOS-based, you also need to know DOS basics.

Video: In order to keep a copy of your captioned video, you need to record from one VCR to another. In addition, if the video you caption is to be produced by a teacher and/or students, they will need to know the basics of operating a camcorder, lighting, camera movements, etc.

Synchronization: Captions can be automatically synchronized to the video; however, many systems are designed for manually sequenced captions only, because synchronization capability adds to the price of the workstation and to the time required to caption. To manually sequence captions, the students and teacher will need to develop a new skill: as the video plays, the student or teacher displays the captions one at a time by pressing a key on the keyboard (in most systems, the same keystroke advances your cursor to the next caption automatically). Many students find this step the most difficult and initially frustrating part of captioning. The activity takes practice and is easier (a) when the captioner is very familiar with the text, or script, and any special cues for displaying or erasing captions, (b) when the captioner has a partner who can provide a prompt for changing captions, and (c) when the captioner or partner has a printout of the caption text to use as a guide.

How Practical is Captioning?

That depends on a number of factors, including how closely the captioning activity fits with the instructional goals of the teacher. Keep in mind that captioning takes longer than other writing activities because it involves more than writing. It also can require a significant amount of teacher preparation, including selecting or producing what the students will caption and deciding what they will write (see Learning with Captioning for ideas on this). In addition, teachers need to consider issues of classroom management; depending on the number of workstations in the classroom, students may need to rotate onto the captioning workstation, or work in pairs or small groups. Teachers should also consider issues of supervision and the independence of their students.

Captioning Technology of the Future:

Captioning technology today uses analog video, consistent with the type of video most commonly found in industry and education. As video and multimedia become digital, captioning technology will follow suit. In fact, captioning capability--the ability to display text on the screen--should be incorporated into standard multimedia workstations. If properly designed into multimedia packages, captioning of the future will not require a separate set of equipment or software, but will be affordable and available to anyone. Dr. Cynthia King and her colleagues at Gallaudet University conduct cutting edge development and research into digital media and captioning. See Digital Media for more information.

Captioning Software Basics:

When considering which captioning system to install in a school, it is important to recognize a number of features or factors.

Word processor: Some software operates with your own word processor, while others have a word processor or text editor built in. If it operates with your own word processor, you will need to make sure it supports the particular word processor you use. You will also need to find out how it incorporates your text into the captioning system and how easy it is to edit that text once it has been converted.

Display style: Captions can either pop on the screen one at a time or roll up line by line (either way, the viewer sees two or three lines of text at a time). Many teachers prefer "pop-on" captions, because roll-up captions scroll upwards during reading. For readers familiar with broadcast captions, pop-on captions are generally found on dramas, sit-coms, most documentaries and children's programs, while roll-up captions are used for many news, public affairs and other live programs. Some software allows the user to choose between the two ways of displaying captions, while others have only one option.

Type style: Most captioning systems create a single style of text, the one designed for closed (broadcast) captioning, also called line-21 captioning. CaptionWorks for the Macintosh, which is still in development, does not use broadcast captioning technology but a video overlay device called the TelevEyes. In addition, the CPC-600 Caption Maker can address the Chyron Codi character generator. These devices give the user options with regard to style, size and color.

Synchronization: Once you've written and corrected your captions, there are two ways to synchronize them to the video, by computer timecode or manually. Before you buy a captioning system, consider the advantages and disadvantages of each. When captions are synchronized by computer, each one appears and disappears at a precise point in time that you enter into the computer in advance. When captions are synchronized by hand, or manually sequenced, they appear and disappear when you touch a key on the keyboard.

Manually sequenced captions are like a performance; make a mistake and you have to restart at the beginning. On the whole though, this is the quickest and least expensive way to caption. Computer-synchronized captions look more professional but require more preparation time, especially if you want the captions to be frame-accurate (accurate to 1/30th of a second). Also, computer-synchronized captions have more technical requirements: your source video (the video you are captioning) must have timecode (a reference point for every frame of video, which you can create yourself with a timecode generator), the video must be high quality to play timecode realiably, and your computer must be able to read the timecode (using a timecode reader board inside the computer). Check with a technical specialist before making the decision to have timecode-driven captions.

Software to create computer-synchronized captions generally costs more than software to create captions sequenced by hand. It also costs more in additional equipment and in preparation time; however, it can be worth it depending on the amount of video you plan to caption, the purpose of the captioned video and your need to create professional-looking captions.

Character Generator & Closed vs. Open Captions: A character generator converts text from your word processor into a form that can be superimposed on your video. Different software addresses different character generators, which vary widely in price. The most common options are the DE352 ($950) from EEG Enterprises, Hubcap ($250) from SoftTouch, TelevEyes (call for educator's price), the Codi character generator from Chyron ($3,000-$4,000) and the Ultech ($3,500) character generator. The DE352 and Hubcap create the type of captions used for broadcast television-white letters inside a black box-known as line-21 captions (named after the line of video where the caption data is broadcast). The TelevEyes, Codi and Ultech create text that looks like film subtitles. Captioning software from ImageLogic has the character generator (line-21 type) built in, but can also address outboard character generators.

Chyron Corporation (Codi)
5 Hub Drive
Melville, NH 11747
(516) 845-2000 phone

Digital Vision, Inc. (TelevEyes)
270 Bridge Street
Dedham, MA 02026
(617) 329-5400 (Voice)
(800) 346-0090 (Toll Free)
(617) 329-6286 (FAX)

EEG Enterprises, Inc. (DE352)
One Rome Street
Farmingdale, NY 11735
(516) 293-7472 phone
(516) 293-7417 fax

Soft Touch, Inc. (Hubcap)
400 N. Columbus Street, Suite 205
Alexandria, VA 22314
(703) 549-8445 phone
(703) 836-8691 fax

28C Great Hill Rd.
Seymour, CT 06483
(203) 735-5805 phone
(203) 735-6653 fax

Controlling the VCR: Some captioning software allows you to control the VCR from the computer keyboard. This is a convenient feature, especially if you are doing a high volume of captioning (as you become more proficient at captioning, this becomes a real time-saver). It usually adds to the price of the software.


Mardi Loeterman, National Center for Accessible Media ,WGBH Educational Foundation 125 Western Avenue, Boston, MA 02134, 617/492-9258 (voice & TTY)

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This material was developed by the National Center to Improve Practice (NCIP), located at Education Development Center, Inc. in Newton, Massachusetts.  NCIP was funded by the U.S. Department of Education, Office of Special Education Programs from October 1, 1992 - September 30, 1998, Grant #H180N20013.  Permission is granted to copy and disseminate this information.  If you do so, please cite NCIP.   Contents do not necessarily reflect the views or policies of the Department of Education, nor does mention of trade names, commercial products, or organizations imply endorsement by NCIP, EDC, or the U.S. Government.  This site was last updated in September 1998. 

ŠEducation Development Center, Inc.