---
title: "AudioFileStreamGetProperty(_:_:_:_:)"
framework: audiotoolbox
role: symbol
role_heading: Function
path: "audiotoolbox/audiofilestreamgetproperty(_:_:_:_:)"
---

# AudioFileStreamGetProperty(_:_:_:_:)

Retrieves the value of the specified property.

## Declaration

```swift
func AudioFileStreamGetProperty(_ inAudioFileStream: AudioFileStreamID, _ inPropertyID: AudioFileStreamPropertyID, _ ioPropertyDataSize: UnsafeMutablePointer<UInt32>, _ outPropertyData: UnsafeMutableRawPointer) -> OSStatus
```

## Parameters

- `inAudioFileStream`: The ID of the parser from which you wish to obtain data. The parser ID is returned by the doc://com.apple.audiotoolbox/documentation/AudioToolbox/AudioFileStreamOpen(_:_:_:_:_:) function.
- `inPropertyID`: A four-character ID indicating the audio file stream property whose value you want to read. See doc://com.apple.audiotoolbox/documentation/AudioToolbox/1391506-audio-file-stream-properties for possible values.
- `ioPropertyDataSize`: On input, the size of the buffer in the outPropertyData parameter. Call the doc://com.apple.audiotoolbox/documentation/AudioToolbox/AudioFileStreamGetPropertyInfo(_:_:_:_:) function to obtain the size of the property value. On output, the number of bytes of the property value returned.
- `outPropertyData`: On output, the value of the specified property.

## Return Value

Return Value A result code. See Result Codes.

## Discussion

Discussion Some Core Audio property values are C types and others are Core Foundation objects. If you call this function to retrieve a value that is a Core Foundation object, then this function—despite the use of “Get” in its name—duplicates the object. You are responsible for releasing the object, as described in The Create Rule in Memory Management Programming Guide for Core Foundation.

## See Also

### Related Documentation

- [AudioFileStreamOpen(_:_:_:_:_:)](audiotoolbox/audiofilestreamopen(_:_:_:_:_:).md)

### Working with Data Stream Property Information

- [AudioFileStreamGetPropertyInfo(_:_:_:_:)](audiotoolbox/audiofilestreamgetpropertyinfo(_:_:_:_:).md)
- [AudioFileStreamSetProperty(_:_:_:_:)](audiotoolbox/audiofilestreamsetproperty(_:_:_:_:).md)