# outputCaptionProviderWithRandomAccess(for:validationDelegate:) Attaches the output to the reader and returns a tuple with an output provider for reading caption groups, and an associated random access controller. ``` func outputCaptionProviderWithRandomAccess(for output: AVAssetReaderTrackOutput, validationDelegate: (any AVAssetReaderCaptionValidationHandling)? = nil) -> sending (AVAssetReaderOutput.Provider, AVAssetReaderOutput.RandomAccessController) ``` ## Parameters `output` The output to be attached to the reader. ## Return Value A tuple with an output provider for reading caption groups, and an associated random access controller. --- 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)