AudioFileGetUserDataAtOffset(_:_:_:_:_:_:)
Gets part of the data from a chunk in an audio file.
Declaration
func AudioFileGetUserDataAtOffset(_ inAudioFile: AudioFileID, _ inUserDataID: UInt32, _ inIndex: UInt32, _ inOffset: Int64, _ ioUserDataSize: UnsafeMutablePointer<UInt32>, _ outUserData: UnsafeMutableRawPointer) -> OSStatusParameters
- inAudioFile:
The audio file whose chunk you want to get data from.
- inUserDataID:
The four-character code of the designated chunk.
- inIndex:
An index that specifies which chunk with the four-character code specified in the
inUserDataIDparameter you want to query. - inOffset:
An offset from the first byte of the chunk to the first byte to get.
- ioUserDataSize:
On input, a pointer to the size of the buffer that contains the designated chunk. On output, a pointer to the size of bytes that the system copied to the buffer.
- outUserData:
A pointer to a buffer in which to copy the chunk data.
Return Value
A result code if there’s an error (see Result Codes) or noErr if the operation succeeds.
Discussion
See AudioFileGetUserDataSize64(_:_:_:_:) for an example of using this function to parse the Audio Definition Model (ADM) of a BW64 file, which is 64-bit and based on WAVE.