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# Closed captioning sample data ('cdat')

A sequence of one or more atoms that store closed captioning sample data.

## Overview

The format of the closed captioning sample data is a sequence of one or more atoms, one of which must be a `'cdat'` atom. Unrecognized atoms should be ignored.

## Topics

### Data fields

[`Size`](/documentation/quicktime-file-format/Closed_captioning_sample_data/Size)

A 32-bit integer that specifies the number of bytes in this closed captioning media data atom.

[`Type`](/documentation/quicktime-file-format/Closed_captioning_sample_data/Type)

A 32-bit integer that identifies the atom type.

[`Sample data`](/documentation/quicktime-file-format/Closed_captioning_sample_data/Sample_data)

An array of one or more byte pairs for data channel 1/field 1 (“CC1”) of a CEA-608 data stream, each byte pair corresponding to a video frame.


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