MediaCentral | UX User’s Guide : Working with Closed Captions in MediaCentral | UX : Basics of Closed Captioning

Basics of Closed Captioning
 
MediaCentral UX provides controls for viewing, creating, editing, and outputting closed captions. The purpose of closed captions is to make video accessible to those who are deaf or hard of hearing, for viewers whose native language is not English, and for instances when the audio cannot be heard due to noise (restaurants, public spaces) or a need for quiet (libraries, hospitals). The following illustration shows a closed caption displayed in the MediaCentral UX media viewer.
The term “closed captions” indicates that the captions are not visible until they are turned on by the viewer, usually through a remote control or menu option. “Open captions” are “burned in” (visible to all viewers) and cannot be turned off.
*In the United States and Canada, “subtitles” are distinguished from closed captions by using subtitles to refer specifically to translation of dialog. In other areas, subtitles can also refer to closed captions, as in “Subtitles for the hard of hearing.”
The FCC (Federal Communications Commission) requires the majority of English and Spanish programming seen on broadcast TV in the United States to be closed captioned. The CRTC (Canadian Radio-television and Telecommunications Commission) requires the same for Canadian broadcasts. Many other countries have their own requirements as well.
Types of Closed Captions
Closed captions can be displayed as one to four rows at any one time. Typically, up to three rows are shown. There are three styles of presenting closed captions:
Pop-on: One or more rows of a caption are displayed (“pop on”) at the same time. A new caption completely replaces an old caption.
Roll-up: Rows of a caption move up the screen one line at a time, giving an appearance of rolling up the screen. Up to three rows are shown.
Paint-on: Each row of a caption is displayed from left to right, one character at a time.
MediaCentral UX currently supports pop-on captions, and roll-up captions that are imported from and exported to SCC files.
Position of Closed Captions
Closed captions can be displayed in various places around the screen, depending on factors like positioning the caption closer to a speaker, centering a caption when a speaker is off screen, or positioning the caption so it does not block content like bugs or burned-in titles.
MediaCentral UX lets you position a closed caption in one of nine positions: top, middle, bottom, and left, center, and right. MediaCentral UX preserves other locations if these positions were set in the original file, but if you change the positioning in MediaCentral UX you cannot restore the original location.
Appearance of Closed Captions
A fixed-width font is used for closed captioning. The specific font depends on the display device. The Media viewer in MediaCentral UX uses the Lucida Console font. Text is displayed as white text on a black box. You can mark text as italics or underscored. You can also add a musical note. Captions that you edit in MediaCentral UX are saved, repackaged, or exported as default normal text, with italics and underscores as applied.
The standard closed caption display can use up to four rows, but typically three or fewer rows are used. Each line can have a maximum of 32 characters, including spaces. To comply with EIA-608 standards, a space before and after italicized or underscored words is required. A space is also required before the first word in the sentence, but not at the end of a sentence. If you do not include a required space, MediaCentral UX displays a message informing you that a space is required.
MediaCentral | UX Closed Caption Editing
Following is important information for working with closed captions in MediaCentral UX v2.4.
Closed caption editing requires Interplay Production v3.3 or later. If the Closed Captioning pane is open, and you try to load a sequence stored in an Interplay Production database earlier than v3.3, a message tells you that Interplay Production v3.3 is required.
You can edit or create closed captions only for Interplay Production sequences. You need to open the sequence in Asset mode. This prevents video or audio editing, so that a user working with closed captions cannot modify the sequence itself.
*There is no locking mechanism for sequences, so other users can edit the sequence while it is open for closed-caption editing. Also, a sequence saved with closed captions can be opened and edited by another user, possibly changing the timing of the closed captions.
You cannot edit closed captions when a sequence is in Output mode. Switch the Media Pane to Asset mode and load the sequence into the Media viewer.
You can edit or create closed captions for sequences in the following formats:
- NTSC formats with a frame rate of 29.97 fps (drop frame or non-drop frame). This support includes 1080i/59.94, which uses a frame rate of 29.97 fps.
- PAL formats 720p/50 and 1080i/50. 1080i/50 uses a frame rate of 25 fps. Send to playback is not currently supported for PAL formats.
You cannot edit or create closed captions for master clips, group clips, subclips, or Interplay MAM assets. If you open one of these assets, the message “This asset type is not supported” is displayed in the Closed Captioning pane.
MediaCentral UX supports all special characters in English and characters used in the following languages:
- Danish
- French
- German
- Italian
- Portuguese
- Spanish
*These characters are listed in technical standard CEA-608-C.
You can mix characters and languages in a single closed caption or a set of closed captions.
All text is displayed in a single set of closed captions. You cannot currently switch between two sets of closed captions (for example, English and Spanish).
Unsupported characters are replaced by a blank when imported or extracted.
Closed-caption editing requires that the ISIS or NEXIS hostname configured for the MCS server use all lower case letters. This is set in the Virtual Host Name in the MediaCentral UX System Settings. Select MCPS > Playback Service and select a Storage Location.
If you are working in a multi-zone environment, you cannot edit closed captions for sequences stored on a remote Interplay Production system.
Currently, only Avid AirSpeed is supported as a playback device.
Currently, only SCC (Scenarist Closed Caption) files are supported for import. SCC and TTML files are supported for export.
A sequence must be dynamically relinked in Media Composer and must be checked into the Interplay Production database before you can extract or add closed captions. If a sequence is transferred from one workgroup to another (such as through Interplay Delivery), a Media Composer system must be available in the target workgroup so that the sequence can be dynamically relinked before you can extract or add closed captions.
If an imported SCC file contains segments with timecodes beyond the end of the sequence, these segments will be lost after a repackaging or export operation.
Closed Captioning Support in Interplay | Access
Interplay Access and Interplay Engine v3.3 and later include features to identify sequences that include closed captions created or edited in MediaCentral UX. These features do not apply to assets that have closed captions created or edited in other applications.
You can use Interplay Access to search for sequences that include closed captions created or edited in MediaCentral UX. To enable this Advanced search feature, select either or both of the following new properties as Available in the System Properties tab of the Interplay Administrator:
- Has Closed Captions: The criterion in search is displayed as “Closed Captions” with options “Has Closed Captions” and “does not have Closed Captions.”
- Closed Captions Modification Time: The criterion in search is displayed as “CC Modification Time” with options for setting the date and time.
Sequences with closed captions that were created or edited in MediaCentral UX are indicated by a thin line under the normal icons.