---
title: CMIOExtensionStream.ClockType.custom
framework: coremediaio
role: symbol
role_heading: Case
path: coremediaio/cmioextensionstream/clocktype-swift.enum/custom
---

# CMIOExtensionStream.ClockType.custom

Indicates that the stream’s clock is specific to the device hosting the stream.

## Declaration

```swift
case custom
```

## Discussion

Discussion The extension doesn’t set this type directly. Instead, the system sets it automatically when you specify a CMIOExtensionStreamCustomClockConfiguration when you create a CMIOExtensionStream.

## See Also

### Clock Types

- [CMIOExtensionStream.ClockType.hostTime](coremediaio/cmioextensionstream/clocktype-swift.enum/hosttime.md)
- [CMIOExtensionStream.ClockType.linkedCoreAudioDeviceUID](coremediaio/cmioextensionstream/clocktype-swift.enum/linkedcoreaudiodeviceuid.md)