Line 21 Settings for Closed Captions

To add text to a video on a DVD, most users use the subtitle feature. To meet accessibility requirements, however, you may also need to consider closed captions.

Note: The closed caption settings apply only to NTSC SD DVD projects.

About Subtitles and Closed Captions

Subtitles have several advantages: You can create them within DVD Studio Pro or using a third-party subtitle authoring application, you can set their font and color, and they can be displayed by any DVD player. Closed captions offer other advantages.

Subtitles generally provide a text version of the dialogue only—they do not describe any other sounds that may be in the title (such as a dog barking or a phone ringing). Closed captions typically include descriptive text along with the dialogue, which makes them better suited for viewers with impaired hearing.

You can add descriptive text to subtitles and make them more similar to the content of closed captions, and there are third-party programs that will convert closed captions to a suitable subtitle format.

Closed captions require a decoder for playback. The decoder can be built in to the television or it can be a standalone box. Computers typically do not have closed caption decoders, so they cannot display captions. The font used by closed captions is determined by the decoder.

Adding Closed Captions to a DVD

With DVD Studio Pro, you can import closed caption files as part of a track. This is the most reliable way to include closed captions with your title.

Do not assume that just because the closed-captioning information was present in the video during the MPEG encode that it will be available when the disc is played by the viewer. Be sure to perform a test before relying on this method of adding closed captions to your title.

Some MPEG encoders can create separate closed caption files that DVD Studio Pro can use to add the function to your disc.

DVD Studio Pro supports closed caption files in the “.cc” and “.scc” formats.

About the Field 1 and Field 2 Settings

The closed caption standard provides for encoding up to four caption streams in Line 21. The two most commonly used streams (C1 and C2) use field 1, and the other two streams (C3 and C4) use field 2.

A closed caption file assigned to a track in DVD Studio Pro can have captions only in field 1 (C1 and C2) or in both fields (support for all four streams). It is important for you to configure the track’s Line 21 settings to match the file’s configuration.

Note: Because the C3 and C4 streams are rarely used, you may assume the closed caption file contains only the C1 and C2 streams, and only supports field 1. Be sure to verify this with a test disc and a DVD player connected to a television monitor before sending your disc to a replicator.

To assign a closed caption file to a track
  1. Select the track so that it appears in the Track Editor and its properties appear in the Inspector.

  2. Click the Other tab in the Track Inspector.

  3. To choose the closed caption file, do one of the following:

    • In the Closed Caption (Line 21) area, click Choose. In the navigation dialog, locate and select the closed caption file to assign to this track. Click Choose.

    • Control-click in the Track Editor’s video stream, then choose Import Line 21 File from the shortcut menu. Locate the closed caption file in the navigation dialog and click Import.

      Figure. Closed Caption section of Other tab of the Track Inspector.
  4. Select the Field 1 and Field 2 boxes to match the configuration of the caption file.

    Note: Most often you should select Field 1 and leave Field 2 unselected.

You can only assign one file to a track.