pixelBufferAndDisplayTime(forItemTime:)
Retrieves an image that is appropriate for display at the specified item time, and marks the image as acquired
Declaration
func pixelBufferAndDisplayTime(forItemTime itemTime: CMTime) -> (pixelBuffer: CVReadOnlyPixelBuffer?, itemTimeForDisplay: CMTime)Return Value
A tuple containing the image to be displayed and a CMTime representing the true display deadline for the pixel buffer
Discussion
itemTime: A CMTime that expresses a desired item time
Typically you would call this method in response to a CADisplayLink delegate invocation and if hasNewPixelBuffer(forItemTime:) also returns true.
The buffer retrieved from pixelBufferAndDisplayTime(forItemTime:) may itself be nil. A nil pixel buffer communicates that nothing should be displayed for the supplied item time.