# AudioConverterFillComplexBufferWithPacketDependencies(_:_:_:_:_:_:_:) ``` func AudioConverterFillComplexBufferWithPacketDependencies(_ inAudioConverter: AudioConverterRef, _ inInputDataProc: AudioConverterComplexInputDataProc, _ inInputDataProcUserData: UnsafeMutableRawPointer?, _ ioOutputDataPacketSize: UnsafeMutablePointer, _ outOutputData: UnsafeMutablePointer, _ outPacketDescriptions: UnsafeMutablePointer?, _ outPacketDependencies: UnsafeMutablePointer) -> OSStatus ``` ## Parameters `inAudioConverter` The audio converter to use for format conversion. `inInputDataProc` A callback function that supplies audio data to convert. This callback is invoked repeatedly as the converter is ready for new input data. `inInputDataProcUserData` Custom data for use by your application when receiving a callback invocation. `ioOutputDataPacketSize` On input, the size of the output buffer (in the `outOutputData` parameter), expressed in number packets in the audio converter’s output format. On output, the number of packets of converted data that were written to the output buffer. `outOutputData` The converted output data is written to this buffer. On entry, the buffers’ `mDataByteSize` fields (which must all be the same) reflect buffer capacity. On exit, `mDataByteSize` is set to the number of bytes written. `outPacketDescriptions` If not `NULL`, and if the audio converter’s output format uses packet descriptions, this must point to a block of memory capable of holding the number of packet descriptions specified in the `ioOutputDataPacketSize` parameter. (See *Audio Format Services Reference* for functions that let you determine whether an audio format uses packet descriptions). If not `NULL` on output and if the audio converter’s output format uses packet descriptions, then this parameter contains an array of packet descriptions. `outPacketDependencies` Should point to a memory block capable of holding the number of packet dependency description structures specified in the `ioOutputDataPacketSize` parameter. Must not be `NULL`. This array will be filled out only by encoders that produce a format which has a non-zero value for `kAudioFormatProperty_FormatEmploysDependentPackets`. ## Return Value A result code. ## Discussion \abstract Converts audio data supplied by a callback function, supporting non-interleaved and packetized formats, and also supporting packet dependency descriptions. \discussion For output formats that use packet dependency descriptions, this must be used instead of AudioConverterFillComplexBuffer, which will return an error for such formats. --- 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)