Subtitling and Closed Captioning

Broadcasters and distributors often have specific requirements about including closed captions and subtitles with a program that you’re delivering for broadcast, for DVD replication, or for archiving.

In the U.S., closed captioning for broadcast is mandated by the Federal Communications Commission (FCC). If you’re delivering tape masters for broadcast, closed captioning may be an important consideration. Subtitles are usually provided as a convenience, although translation to a country’s native language may be required for film festival or theatrical exhibition and will certainly enhance your ability to find theatrical or DVD distribution there.

For more information, see:

Handling Closed Captioning

Closed captioning is a subtitling system designed to make television more accessible to the hearing-impaired. Unlike movie subtitles, which are intended to translate dialogue for people who can hear the rest of the soundtrack, closed captions need to convey all important sound effects, music cues, nonverbal expressions, and dialogue that occur as a program plays.

The FCC mandates that distributors of programming for residential use must provide a minimum number of hours of closed-captioned programming per calendar quarter. This rule affects terrestrial and satellite broadcasters as well as cable operators. Although there are exceptions, the result is that many broadcasters insist on a closed-captioned tape master as one of their deliverables.

Closed captioning is encoded in a variety of ways, depending on the video format.

  • SD analog and digital NTSC broadcast, tape, and DVDs: Closed captioning for SD analog television is a text-only data stream that’s encoded into line 21 of an NTSC video signal. This is one of the reasons for the series of blinking dashes and lines that runs along the edge of a video image when you put a monitor into underscan mode. SD digital video uses the CEA-608 standard of closed captioning, which can be encoded into an MPEG-2 stream. Because closed captioning is encoded right into the video signal, it can be included and recorded on videotapes; broadcast over the air, via satellite or cable; included on DVDs; and even recorded using digital video recorders (DVRs) such as TIVO.
  • SD and HD digital television broadcast and tape: Although high definition television (HDTV) originally supported line 21–style closed captioning, the proliferation of new HD digital video formats necessitated a new approach. To accommodate HD video encoded using a variety of methods, the EIA-708 closed captioning standard for ATSC digital television was developed. This standard has since been superseded by CEA-708, which covers both SD and HD digital television. In this standard, closed captioning data is stored in the vertical ancillary (VANC) data of a digital video stream. Final Cut Pro and Compressor both support the embedding of CEA-608 closed captioning within the CEA-708 standard.
  • European television: Closed captioning in European television is based on teletext, a text-only information retrieval system for television originally developed in England. Digital broadcasters in Europe currently use the DVB-T and DVB-S standards for encoding teletext-style data into digital video streams. Final Cut Studio does not support these standards.

Closed captioning is actually displayed by the television receiving the video signal, which means that it can be turned on and off at will. This also means that the font and style of the closed captioning is dependent on the television. Closed captions are simply plain text.

Capturing Video with Closed Captioning Using Final Cut Pro

If you’re using a video capture card that supports the preservation of closed captioning, closed captioning is preserved during capture in one of two ways:

  • The Apple ProRes codecs support the capture and preservation of either line 21 or VANC closed captioning data, including both the CEA-608 (for SD) and CEA-708 (for HD) standards of closed captioning.

  • Apple’s 8- and 10-bit Uncompressed 4:2:2 codecs preserve line 21 closed captioning. However, the Apple Uncompressed codecs do not preserve VANC closed captioning data directly. Instead, if VANC closed captioning is present in a video signal being captured, it is extracted and preserved via a QuickTime closed captioning track.

Outputting Video with Closed Captioning Using Final Cut Pro

When outputting to tape, either CEA-608 or CEA-708 closed captioning can be encoded to the video stream being output using the Closed Captions controls in the Print to Video and Edit to Tape windows. Select “Insert closed captioning data from file,” click the Choose File button, and choose one of the following:

  • A Scenarist-formatted file (with an .scc extension)

  • A QuickTime file with a closed captioning track

Scenarist files are always CEA-608 encoded. This means that if you output a program with a Scenarist-formatted closed captioning file to an HD tape format, Final Cut Pro outputs CEA-708 closed captioning that “carries” CEA-608-formatted closed captioning (supported by QuickTime 7.6 and later).

However, you can use a third-party utility (such as CPC MacCaption) to reformat CEA-608 closed captioning as true CEA-708-encoded closed captioning, saving the result as a QuickTime closed captioning track that you can use for output instead.

Adding Closed Captioning Using Compressor

Using Compressor, you can insert a closed caption track into a movie file being encoded by choosing either a Scenarist file (identifiable by the .scc file extension) or a QuickTime file with a closed caption track. These options are available in the Additional Information tab of the Inspector window and let you include closed captioning in the following formats:

  • For QuickTime output: Compressor can add a closed caption file as a CEA-608 closed caption track within the QuickTime output file. Closed captions can be viewed using QuickTime Player (version 7.2 or later).
  • For MPEG-2 elementary stream output: Compressor embeds CEA-608 closed captioning data in an elementary MPEG-2 video stream so that it can be used for authoring in DVD Studio Pro. DVD Studio Pro retains this closed captioning data when the video stream is added to a track of a standard definition NTSC DVD project. You can use Apple DVD Player to play the resulting DVD Studio Pro build files to verify that the closed captioning data is present.
  • For MPEG-2 program and transport stream output: Compressor embeds the closed captioning data in program and transport MPEG-2 streams using the CEA-708 standard.

The timecode values used to synchronize the text with the video must be based on those of the source media file being encoded. Scenarist files contain timecode-delineated lines of closed captioning data in two-byte hexadecimal format. These files are not easily readable and are typically created using specialized third-party applications.

Adding Closed Captioning Using Third-Party Utilities and Hardware

There are third-party applications, such as MacCaption from CPC, that provide the means to import transcripts, edit them with timing information, encode closed captioning data in the necessary format, and insert the closed captioning data into a QuickTime file in preparation for tape output or DVD encoding.

Having Someone Else Do It

It’s very common to have another post-production facility take care of your closed captioning needs. Some facilities do all the transcribing, whereas others request a transcript prepared in advance. Some facilities do the insertion while outputting the program to tape, and others can insert closed captioning onto a previously recorded videotape.

Handling Subtitles

Subtitling is usually done for the purpose of translating either particular scenes or an entire program. It may be done because the dialogue is in another language or because the dialogue is simply unintelligible to the intended audience. If you need to add subtitles to your program, there are two primary methods using Final Cut Studio.

Adding Subtitles Using Text Generators in Final Cut Pro

The easiest way to add permanent subtitles (sometimes called open captioning) to your program is also the most time-consuming: editing superimposed text generators into your sequence one at a time. If you follow this workflow, it’s best to add one or two dedicated video tracks to contain every subtitle you create. You can then easily turn them all off and on at once using the Track Visibility controls.

Tip: If you’re adding subtitles manually, consider using a master template created in Motion. This way, you can easily change the look or formatting of all your subtitles at once, if necessary. For more information, see Using Master Templates in Final Cut Pro.

You can also use a third-party utility. Most subtitling utilities take advantage of the Final Cut Pro XML Interchange Format to automate the process of creating subtitles to match a timed script that you provide. Some subtitling utilities provide an interface for actually assembling the script, whereas others require one that’s premade. Most of these utilities use one of two approaches. Some facilitate the automated placement of text generators within your sequence, whereas others automatically create TIFF graphics that are edited into your sequence. Do a bit of research to determine which of these approaches best suits your needs.

Adding Subtitles in DVD Studio Pro

The DVD standard is designed to accommodate up to 32 subtitle streams, which makes it possible to offer subtitles in multiple languages for international distribution. The viewer is then able to select the appropriate language to view using the DVD player’s controls.

There are two ways you can create subtitles in DVD Studio Pro. You can create them manually, one at a time, by entering timecode values or dragging in the Timeline and then setting the position, font, size, style, color, and start and end fades of each subtitle.

You can also import specially formatted files that contain all of the subtitles for a particular video track. DVD Studio Pro supports subtitle files in the following formats:

  • STL: The Spruce Technologies subtitle format
  • SON: The Sonic Solutions bitmap-based format
  • TXT: A plain text file
  • SCR: The Daikin U.S. Comtec Laboratories Scenarist bitmap-based format

The timecode values used to synchronize the text with the video must be based on those of the encoded MPEG-2 program.

Adding Text Tracks to QuickTime Movies

QuickTime supports dedicated text tracks that can be turned on and off by the viewer within QuickTime Player. These text tracks are useful for programs intended for Internet distribution. The QuickTime format supports multiple text tracks that users can switch among, and individual text tracks can be identified as one of a standardized list of languages, to provide international support. Additionally, text in QuickTime text tracks can be extensively formatted using a variety of descriptors for font, size, color, background, justification, aliasing, and so on. These options make QuickTime text tracks extremely versatile for multimedia use.

Text tracks can be formatted by hand in any text editor and then inserted into a QuickTime movie using QuickTime Player. For more information, go to http://www.apple.com/quicktime/tutorials/texttracks.html. You can also use one of several third-party utilities to create and format text tracks in a more structured fashion.