Type Alias


Prototype for the block invoked when frame compression is complete.


typedef void (^VTCompressionOutputHandler)(OSStatus status, VTEncodeInfoFlags infoFlags, CMSampleBufferRef sampleBuffer);



noErr if compression was successful; an error code if compression was not successful.


Contains information about the encode operation.

The kVTEncodeInfo_Asynchronous bit may be set if the encode ran asynchronously.

The kVTEncodeInfo_FrameDropped bit may be set if the frame was dropped.


Contains the compressed frame if compression was successful and the frame was not dropped; otherwise, NULL.


When you encode a frame, you pass in a callback block to be called for that compressed frame. This block is called in decode order (which is not necessarily the same as display order).

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