The process of converting the audio portion of a production into text that can be displayed using several mediums: videotape, DVD, film, webcasting and video CDs. Captions are typically white, uppercase letters on a black background.
OFF-LINE CAPTIONING
The quality alternative for programs taped in advance. Captions are created from your final recorded master rather than during the live recording. A transcript of the program's dialogue is used to create a caption file which is properly edited and precisely synchronized with your master's audio and video.
Pop-on or Roll-up caption styles can be used.
CLOSED CAPTIONS
A decoding device is required to view these captions. Closed captions are recorded on Line 21 of the vertical blanking interval of the television signal and made visible by using a decoder. All televisions made after July 1993 which are 13 inches or larger are required to have built-in decoders.
OPEN CAPTIONS
Captions that are visible without using a decoder. When a video is open captioned, the captions are a permanent part of the picture.
CLOSED CAPTION DECODER
A small electronic device that decodes the captioning signal recorded on Line 21 of the vertical blanking interval of the television signal. All televisions made after July 1993 which are 13 inches or larger are required to have built-in decoders.
CAPTION DISK
A computer disk that stores a program's caption data which includes the text, placement and timing information. The caption disk is used in conjunction with an encoder to create the captioned submaster.
ENCODING
The process of inserting the caption data onto Line 21 of the vertical blanking interval of the television signal.
ENCODER
A device that electronically inserts the caption data onto Line 21 of the vertical blanking interval of the television signal.
LINE 21
The television signal is comprised of 525 lines. The vertical blanking interval includes Line 1 through 21. Caption information is recorded on Line 21 and the active video begins on Line 22.
TIME CODE
An electronic signal embedded in a videotape that identifies each frame of video
by hours, minutes, seconds and frames: hh:mm:ss:ff.
MASTER
The first generation videotape of the final edited version of a program. The master is the source tape used to create a captioned submaster.
SUBMASTER
Any duplicate tapes created from the master video. The captioned videotape is a submaster of the original master.
SUBTITLES
Subtitles are a permanent part of the picture and are visible at all times. You do not need a decoder to view subtitles. Subtitles are created with a character generator and can appear in upper and lowercase letters. They do not appear in a black background and are typically placed at the bottom of the screen.
POP-ON CAPTIONS
Pop-on captions are timed to pop on and off the screen. They are precisely timed with your master's audio utilizing time codes to synchronize each frame. The caption blocks contain 1 to 3 lines of text and are carefully placed on the screen to avoid covering up text, graphics or critical parts of the video. Pop-on captions are positioned on the screen to appear with the speaker and are the preferred viewing style of the hearing impaired. They are used mostly for TV programs and movies, home videos, commercials and music videos.
ROLL-UP CAPTIONS
With this caption style, the text appears line-by-line and creates a two- to three-line block of captions. The text rolls up from either the bottom or top of the screen. As one line of text rolls up and disappears, a new bottom line is added. Roll-up captions follow double chevrons (>>) which are used to indicate different speaker identifications. Roll-up captioning is more economical and requires less time to produce in the post production process. Roll-up captions are often preferred for documentaries, newscasts, educational programs and corporate training tapes.
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