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# Audio Format Services

Access information about audio formats and codecs.

## Discussion

This document describes Audio Format Services, a C interface for obtaining information about audio formats and codecs.

## Topics

### Audio Format Services Functions

[`AudioFormatGetProperty`](/documentation/AudioToolbox/AudioFormatGetProperty(_:_:_:_:_:))

Gets the value of an audio format property.

[`AudioFormatGetPropertyInfo`](/documentation/AudioToolbox/AudioFormatGetPropertyInfo(_:_:_:_:))

Gets information about an audio format property.

### Data Types

[`AudioBalanceFade`](/documentation/AudioToolbox/AudioBalanceFade)

Describes audio left/right balance and front/back fade values.

[`AudioFormatInfo`](/documentation/AudioToolbox/AudioFormatInfo)

A structure that specifies an audio format.

  <doc://com.apple.documentation/documentation/CoreAudioTypes/AudioFormatListItem>

[`AudioPanningInfo`](/documentation/AudioToolbox/AudioPanningInfo)

Audio panning information.

[`ExtendedAudioFormatInfo`](/documentation/AudioToolbox/ExtendedAudioFormatInfo)

A specifier for the [`kAudioFormatProperty_FormatList`](/documentation/AudioToolbox/kAudioFormatProperty_FormatList) property, including the codec to use.

[`AudioFormatPropertyID`](/documentation/AudioToolbox/AudioFormatPropertyID)

A type for four-char codes for audio format property identifiers.

### Constants

[`AudioBalanceFadeType`](/documentation/AudioToolbox/AudioBalanceFadeType)

Identifiers for audio balance fade types.

[Audio Format Property Identifiers](/documentation/AudioToolbox/1577853-audio-format-property-identifier)

Constants for use with the [`AudioFormatGetPropertyInfo(_:_:_:_:)`](/documentation/AudioToolbox/AudioFormatGetPropertyInfo(_:_:_:_:)) and [`AudioFormatGetProperty(_:_:_:_:_:)`](/documentation/AudioToolbox/AudioFormatGetProperty(_:_:_:_:_:)) functions.

[Audio Codec Component Constants](/documentation/AudioToolbox/1494086-audio-codec-component-constants)

Audio codec component types.

[Audio Codec Manufacturer and Implementation Types](/documentation/AudioToolbox/1620448-audio-codec-manufacturer-and-imp)

Identifiers for audio codec manufacturers and implementation types.

[`AudioPanningMode`](/documentation/AudioToolbox/AudioPanningMode)

Identifiers for audio panning algorithms.

### Result Codes

This table lists the result codes defined for Audio Format Services.

[Audio Format Error Codes](/documentation/AudioToolbox/1577851-audio-format-error-codes)

[`kAudioFormatUnspecifiedError`](/documentation/AudioToolbox/kAudioFormatUnspecifiedError)

An unspecified error.

[`kAudioFormatUnsupportedPropertyError`](/documentation/AudioToolbox/kAudioFormatUnsupportedPropertyError)

The specified property is not supported.

[`kAudioFormatBadPropertySizeError`](/documentation/AudioToolbox/kAudioFormatBadPropertySizeError)

[`kAudioFormatBadSpecifierSizeError`](/documentation/AudioToolbox/kAudioFormatBadSpecifierSizeError)

[`kAudioFormatUnsupportedDataFormatError`](/documentation/AudioToolbox/kAudioFormatUnsupportedDataFormatError)

The playback data format is unsupported (declared in `AudioFormat.h`).

[`kAudioFormatUnknownFormatError`](/documentation/AudioToolbox/kAudioFormatUnknownFormatError)

The specified data format is not a known format.


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