# AVAudioIONodeInputBlock The type that represents a block to render operation calls to get input data when in manual rendering mode. ``` typealias AVAudioIONodeInputBlock = (AVAudioFrameCount) -> UnsafePointer? ``` ## Parameters `inNumberOfFrames` The number of frames the system needs to complete the request. ## Return Value An that contains the data to render, or `nil` if no data is available. ## Discussion Don’t clear or refill the data in the return value until the framework calls the input block again or the rendering finishes. The format of the buffer list must match the format you specify when registering the block. --- 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)