AVVideoCompositionInstruction Protocol Reference

Conforms to
Framework
/System/Library/Frameworks/AVFoundation.framework
Availability
Available in iOS 7.0 and later.
Declared in
AVVideoCompositing.h

Overview

The AVVideoCompositionInstruction protocol represents operations to be performed by a compositor. An AVVideoComposition object maintains an array of instructions to perform its composition.

Tasks

Getting Track ID Settings

Getting Tweening Settings

Getting Post Processing Status

Getting Timing Settings

Properties

containsTweening

A Boolean value that indicates whether the composition contains tweening. (required) (read-only)

@property(nonatomic, readonly) BOOL containsTweening
Discussion

If YES, rendering a frame from the same source buffers and the same composition instruction at two different compositionTime may yield different output frames. If NO, two such compositions will yield the same frame.

The media pipeline may be able to avoid some duplicate processing when this property is set to NO.

Availability
  • Available in iOS 7.0 and later.
Declared In
AVVideoCompositing.h

enablePostProcessing

A Boolean value that indicates whether post-processing is enabled for a composition. (required) (read-only)

@property(nonatomic, readonly) BOOL enablePostProcessing
Discussion

If NO, indicates that post-processing should be skipped for the duration of this instruction.

Availability
  • Available in iOS 7.0 and later.
Declared In
AVVideoCompositing.h

passthroughTrackID

Ehe track ID of the video composition if a single source frame should be displayed for the duration of the instruction. (required) (read-only)

@property(nonatomic, readonly) CMPersistentTrackID passthroughTrackID
Discussion

If for the duration of the instruction, the video composition result is one of the source frames, this property returns the corresponding track ID. The compositor won't be run for the duration of the instruction and the proper source frame is used instead.

The dimensions, clean aperture and pixel aspect ratio of the source buffer are matched to the required values automatically.

Availability
  • Available in iOS 7.0 and later.
Declared In
AVVideoCompositing.h

requiredSourceTrackIDs

An array of video track IDs required to compose frames for this instruction. (required) (read-only)

@property(nonatomic, readonly) NSArray *requiredSourceTrackIDs
Availability
  • Available in iOS 7.0 and later.
Declared In
AVVideoCompositing.h

timeRange

The time range during which the instruction is effective. (required) (read-only)

@property(nonatomic, readonly) CMTimeRange timeRange
Discussion

See the AVVideoComposition class instructions property for information on the requirements for the timeRanges of instructions.

Availability
  • Available in iOS 7.0 and later.
See Also
Declared In
AVVideoCompositing.h