An object that transcodes the contents of an asset source object to create an output of the form described by a specified export preset.
SDKs
- iOS 4.0+
- macOS 10.7+
- Mac Catalyst 13.0+
- tvOS 9.0+
Framework
- AVFoundation
Declaration
class AVAssetExportSession : NSObject
Overview
Prior to initializing an instance of AVAsset
, you can use all
to get the complete list of presets available. Use export
to get a list of presets that are compatible with a specific asset.
After you have initialized an export session with the asset that contains the source media, the export preset name (preset
), and the output file type (output
), you can start the export running by invoking export
. Because the export is performed asynchronously, this method returns immediately—you can use progress
to check on the progress. Depending on the capabilities of the device, some exports may be queued when multiple exports are attempted. When this happens, the status
of a queued export will indicate that it's waiting (AVAsset
).
The completion handler you supply to export
is called whether the export fails, completes, or is cancelled. Upon completion, the status
property indicates whether the export has completed successfully. If it has failed, the value of the error
property supplies additional information about the reason for the failure.