An object that describes the requirements, such as source time ranges to append or re-append, to the current pass.
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
If the value of this property is
nil, there is no request to be fulfilled and
mark should be called on the asset writer input.
During the first pass, the request will contain a single time range from zero to positive infinity, indicating that all media from the source should be appended. This will also be true when
NO, in which case only one pass will be performed.
The value of this property will be
start is called on the attached asset writer. It will transition to an initial non-
nil value during the call to
start. After that, the value of this property will change only after a call to
respond method allows for notification at the beginning of each pass.
This property supports Key-value observing. Observers should not assume that they will be notified of changes on a specific thread.