# AudioConverterInputDataProc Deprecated. Use [`AudioConverterFillComplexBuffer(_:_:_:_:_:_:)`](/documentation/AudioToolbox/AudioConverterFillComplexBuffer(_:_:_:_:_:_:)) instead. ``` typealias AudioConverterInputDataProc = (AudioConverterRef, UnsafeMutablePointer, UnsafeMutablePointer, UnsafeMutableRawPointer?) -> OSStatus ``` ## Discussion If you named your callback function `MyAudioConverterInputDataProc`, you would declare it like this: ### Discussion This deprecated callback supplies input data to the [`AudioConverterFillBuffer`](/documentation/AudioToolbox/AudioConverterFillBuffer) function. Use [`AudioConverterComplexInputDataProc`](/documentation/AudioToolbox/AudioConverterComplexInputDataProc) instead. --- 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)