pub unsafe static AVMediaCharacteristicTranscribesSpokenDialogForAccessibility: Option<&'static AVMediaCharacteristic>AVMediaFormat only.Expand description
A media characteristic that indicates that a track or media selection option includes legible content in the language of its specified locale that:
- transcribes spoken dialog and
- identifies speakers whenever other visual cues are insufficient for a viewer to determine who is speaking.
Legible tracks provided for accessibility purposes are typically tagged both with this characteristic as well as with AVMediaCharacteristicDescribesMusicAndSoundForAccessibility.
A legible track provided for accessibility purposes that’s associated with an audio track that has no spoken dialog can be tagged with this characteristic, because it trivially meets these requirements.
The value of this characteristic is “ public.accessibility.transcribes-spoken-dialog“.
Note for content authors: for QuickTime movie and .m4v files a media option is considered to have the characteristic AVMediaCharacteristicTranscribesSpokenDialogForAccessibility only if it’s explicitly tagged with that characteristic. See the discussion of the tagging of tracks with media characteristics below.
Also see -[AVAssetTrack hasMediaCharacteristic:] and -[AVMediaSelectionOption hasMediaCharacteristic:].
See also Apple’s documentation