About Final Cut Pro X caption validation

Final Cut Pro automatically checks your captions for errors as you edit.

Final Cut Pro supports three caption formats—CEA-608, iTT, and SRT. Each format has certain specifications it must meet. Final Cut Pro continuously validates your captions as you edit. When a caption doesn’t meet the specifications of a caption format, Final Cut Pro instantly alerts you in several ways:

  • Invalid captions turn red in the caption lane in the timeline.
  • A message appears in the Validation section of the Captions inspector, with helpful suggestions on how to fix the error.

iTT validation error messages

There are three types of iTT caption validation error messages: overlap errors, invalid character errors, or too many lines of text errors.

Overlap error

In all languages except Japanese, captions can’t overlap in time. In Japanese, captions can overlap in time if they’re placed in different areas of the screen. If you get an overlap error, change the position or the duration of the caption. Or, choose Edit > Captions > Resolve Overlaps.

Invalid character

The ITT format supports most of the unicode character set. However, if you’re creating an iTunes Store Package, some characters might prevent your project from being accepted by the iTunes Store. Remove the invalid characters.

Too many lines of text

For all languages except for Japanese, iTT allows for one line break (two lines of text) per caption.  For Japanese, iTT allows for three line breaks (four lines). Create a new caption for the extra text.

CEA-608 validation error messages

The CEA-608 format provides three caption display styles available: Pop-On, Paint-On, and Roll-Up. Because each of these styles is encoded into the video differently, you might encounter some of these errors with certain styles only.

Timing errors

Formatting text in the CEA-608 format adds control characters to captions, which appear as blank spaces before lines of text in a caption. Control characters make the lines of text in a caption longer. Because CEA-608 has a 32-character limit per line, these added control characters can create timing errors between adjacent captions.

You can’t delete control characters in the caption editor. If you want to keep the text formatting, you have to move some of the text from the caption with the error to another caption. Or, remove some of the formatting in the original caption.

Here are the three types of timing errors you might encounter with CEA-608.

Captions occur too close

This occurs when a caption begins too close to the beginning of the project timeline, or too close to the previous caption. Final Cut Pro suggests where to move the caption to fix the error. You are more likely to encounter this error with Pop-On captions.

Caption duration is too short

To fix this error, extend the duration of the caption in the timeline.

Caption occurs too close to the end of the project

A caption can’t extend beyond the end of a project. To fix this error, shorten the caption.

Adjacent caption error

This occurs when a caption is too close to an adjacent caption. To fix this error, in the timeline, move the caption with this error message away from the adjacent caption. This error occurs when you’re using Paint-On and Roll-Up captions.

Formatting error

If you’ve changed the formatting of text in a caption, it can add space that might cut off the text at the end of the caption. If you want to keep the formatting, you’ll have to insert a line break, or move the truncated text to an existing or new caption.

Invalid character

CEA-608 supports a limited number of languages and character sets. To fix this error, remove the invalid character.

Too many lines of text

CEA-608 characters are positioned on a grid of 15 lines and 32 columns.  If you type more text than will fit on a line, you’ll encounter this error. To fix this error, create a new caption for the extra lines of text.

SRT validation error messages

SRT captions have two validation warnings: overlap errors and invalid characters errors.

Overlap error

Captions can't overlap in time. If you get an overlap error, change the position or the duration of the caption. Or, choose Edit > Captions > Resolve Overlaps.

Invalid characters error

SRT captions can't have multiple adjacent line breaks. If you encounter this error, remove any extra line breaks until Final Cut Pro validates the caption.

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