Global Variable


The track contains the same content as another track, but in a more widely supported format.


const AVTrackAssociationType AVTrackAssociationTypeAudioFallback;


A player that does not support the format of the original track can use the fallback track instead. For example, an asset may contain both stereo and a 5.1-channel audio tracks. In this case, marking the stereo track as the fallback for the 5.1-channel track would ensure that devices not capable of playing 5.1-channel audio can still play an equivalent track.

See Also

Track Association Types


The associated track contains chapter information for the base track.


The subtitle track containing forced and non-forced subtitles is associated with a subtitle track containing only forced subtitles.


The metadata track is associated with the track being described or annotated.


The second track in the association is considered an appropriate default for the first track.


The track is associated with a timecode track containing timing information for the original track.