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# CMIOExtensionProperty

A structure that defines the properties that providers, devices, and streams support.

```
struct CMIOExtensionProperty
```

## Topics

### Provider Properties

[`providerName`](/documentation/CoreMediaIO/CMIOExtensionProperty/providerName)

A property key for the provider name.

[`providerManufacturer`](/documentation/CoreMediaIO/CMIOExtensionProperty/providerManufacturer)

A property key for the provider manufacturer.

### Device Properties

[`deviceModel`](/documentation/CoreMediaIO/CMIOExtensionProperty/deviceModel)

A property key for the device model.

[`deviceIsSuspended`](/documentation/CoreMediaIO/CMIOExtensionProperty/deviceIsSuspended)

A property key for a Boolean value that indicates whether the device is in a suspended state.

[`deviceTransportType`](/documentation/CoreMediaIO/CMIOExtensionProperty/deviceTransportType)

A property key for the device transport type.

[`deviceLinkedCoreAudioDeviceUID`](/documentation/CoreMediaIO/CMIOExtensionProperty/deviceLinkedCoreAudioDeviceUID)

A property key for the UID of the linked Core Audio device.

[`deviceCanBeDefaultInputDevice`](/documentation/CoreMediaIO/CMIOExtensionProperty/deviceCanBeDefaultInputDevice)

A property key for a Boolean value that indicates whether the device can be a default input device.

[`deviceCanBeDefaultOutputDevice`](/documentation/CoreMediaIO/CMIOExtensionProperty/deviceCanBeDefaultOutputDevice)

A property key for a Boolean value that indicates whether the device can be a default output device.

### Stream Properties

[`streamActiveFormatIndex`](/documentation/CoreMediaIO/CMIOExtensionProperty/streamActiveFormatIndex)

A property key for the index of the active stream format.

[`streamFrameDuration`](/documentation/CoreMediaIO/CMIOExtensionProperty/streamFrameDuration)

A property key for the frame duration.

[`streamMaxFrameDuration`](/documentation/CoreMediaIO/CMIOExtensionProperty/streamMaxFrameDuration)

A property key for the maximum frame duration.

[`streamSinkBufferQueueSize`](/documentation/CoreMediaIO/CMIOExtensionProperty/streamSinkBufferQueueSize)

A property key for the sink buffer queue size.

[`streamSinkBuffersRequiredForStartup`](/documentation/CoreMediaIO/CMIOExtensionProperty/streamSinkBuffersRequiredForStartup)

A property key for the number of buffers required for startup.

[`streamSinkBufferUnderrunCount`](/documentation/CoreMediaIO/CMIOExtensionProperty/streamSinkBufferUnderrunCount)

A property key for the buffer underrun count.

[`streamSinkEndOfData`](/documentation/CoreMediaIO/CMIOExtensionProperty/streamSinkEndOfData)

A property key for a Boolean value that indicates whether the stream has more data.

### Type Properties

[`deviceLatency`](/documentation/CoreMediaIO/CMIOExtensionProperty/deviceLatency)

[`streamLatency`](/documentation/CoreMediaIO/CMIOExtensionProperty/streamLatency)


---

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