Instance Property


The boundary, in bytes, for aligning media chunks.


@property(nonatomic) NSInteger preferredMediaChunkAlignment;


This property supports file types that support media chunk alignment, such as QuickTime Movie files. The default value is 0, which means that the receiver will choose an appropriate default value. A value of 1 implies that no padding should be used to achieve a particular chunk alignment. It is an error to set a negative value for chunk alignment.

This property cannot be set after startWriting has been called for the receiver.

See Also

Performing Multiple-Pass Encoding


A Boolean value that indicates whether the input might perform multiple passes over appended media data.


An object that describes the requirements, such as source time ranges to append or re-append, to the current pass.

- markCurrentPassAsFinished

Instructs the receiver to analyze the appended media data and determine whether to improve the results by re-encoding certain segments.


A Boolean value that indicates whether the input should attempt to encode the source media data using multiple passes.


The duration used for each chunk of sample data in the output file.

- respondToEachPassDescriptionOnQueue:usingBlock:

Instructs the receiver to invoke a client-supplied block whenever a new pass has begun.