Returns the identifiers compatible with a given asset.
- iOS 4.0+
- macOS 10.7+
- tvOS 9.0+
An asset that is ready to be exported.
An array of
NSString objects representing the identifiers compatible with
The array is a complete list of the valid identifiers that can be used with
export with the specified asset. For possible values, see Export Preset Names for Device-Appropriate QuickTime Files, Export Preset Names for QuickTime Files of a Given Size,
AVAsset, Export Preset Name for iTunes Audio, and Export Preset Name for Pass-Through.
Not all export presets are compatible with all assets. For example, a video-only asset is not compatible with an audio-only preset. This method returns only the identifiers for presets that are compatible with the given asset.
In order to ensure that the setup and running of an export operation will succeed using a given preset, you should not make significant changes to the asset (such as adding or deleting tracks) between retrieving compatible identifiers and performing the export operation.
If the asset’s tracks are not currently loaded, they may be loaded by this method before any checks are performed.