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# AudioUnitParameterOptions

Value options for audio unit parameters.

```
struct AudioUnitParameterOptions
```

## Overview

These constants are relevant only in macOS, and not in iOS.

Audio unit parameter flags, for use in the [`AudioUnitParameterInfo`](/documentation/AudioToolbox/AudioUnitParameterInfo) data structure , serve as a dictionary-like set of information about an audio unit parameter. Parameter flag bit position 19 is reserved.

## Topics

### Constants

[`flag_CFNameRelease`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_CFNameRelease)

If an audio unit can generate parameter names dynamically, it should set this flag.

[`flag_CanRamp`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_CanRamp)

[`flag_DisplayCubeRoot`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_DisplayCubeRoot)

[`flag_DisplayCubed`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_DisplayCubed)

[`flag_DisplayExponential`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_DisplayExponential)

[`flag_DisplayLogarithmic`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_DisplayLogarithmic)

[`flag_DisplayMask`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_DisplayMask)

[`flag_DisplaySquareRoot`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_DisplaySquareRoot)

[`flag_DisplaySquared`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_DisplaySquared)

[`flag_ExpertMode`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_ExpertMode)

[`flag_HasCFNameString`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_HasCFNameString)

[`flag_HasClump`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_HasClump)

[`flag_IsElementMeta`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_IsElementMeta)

[`flag_IsGlobalMeta`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_IsGlobalMeta)

[`flag_IsHighResolution`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_IsHighResolution)

[`flag_IsReadable`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_IsReadable)

[`flag_IsWritable`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_IsWritable)

[`flag_MeterReadOnly`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_MeterReadOnly)

[`flag_NonRealTime`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_NonRealTime)

[`flag_OmitFromPresets`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_OmitFromPresets)

[`flag_PlotHistory`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_PlotHistory)

If set, getting the `kAudioUnitProperty_ParameterHistoryInfo` property fills out the [`AudioUnitParameterHistoryInfo`](/documentation/AudioToolbox/AudioUnitParameterHistoryInfo) struct containing the recommended update rate and history duration.

[`flag_ValuesHaveStrings`](/documentation/AudioToolbox/AudioUnitParameterOptions/flag_ValuesHaveStrings)


---

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