# start(_:ofImageParameter:) Provides the start time of the clip the user assigned to the given image parameter for the effect. ``` func start(_ startTime: UnsafeMutablePointer!, ofImageParameter parameterID: UInt32) ``` ## Parameters `startTime` The start time of the clip, in `CMTime`. `parameterID` The ID of the image parameter. ## Discussion In Motion, `startTime` represents the native start time of the image well input, relative to timeline time. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)