---
title: "CVDisplayLinkGetNominalOutputVideoRefreshPeriod(_:)"
framework: corevideo
role: symbol
role_heading: Function
path: "corevideo/cvdisplaylinkgetnominaloutputvideorefreshperiod(_:)"
---

# CVDisplayLinkGetNominalOutputVideoRefreshPeriod(_:)

Retrieves the nominal refresh period of a display link.

## Declaration

```swift
func CVDisplayLinkGetNominalOutputVideoRefreshPeriod(_ displayLink: CVDisplayLink) -> CVTime
```

## Parameters

- `displayLink`: The display link whose refresh period you want to obtain.

## Return Value

Return Value A CVTime structure that holds the nominal refresh period. This value is indefinite if an invalid display link was specified.

## Discussion

Discussion This call allows one to retrieve the device’s ideal refresh period.   For example, an NTSC output device might report 1001/60000 to represent the exact NTSC vertical refresh rate.

## See Also

### Inspecting Display Links

- [CVDisplayLinkGetCurrentCGDisplay(_:)](corevideo/cvdisplaylinkgetcurrentcgdisplay(_:).md)
- [CVDisplayLinkGetCurrentTime(_:_:)](corevideo/cvdisplaylinkgetcurrenttime(_:_:).md)
- [CVDisplayLinkTranslateTime(_:_:_:)](corevideo/cvdisplaylinktranslatetime(_:_:_:).md)
- [CVDisplayLinkGetActualOutputVideoRefreshPeriod(_:)](corevideo/cvdisplaylinkgetactualoutputvideorefreshperiod(_:).md)
- [CVDisplayLinkGetOutputVideoLatency(_:)](corevideo/cvdisplaylinkgetoutputvideolatency(_:).md)
- [CVDisplayLinkIsRunning(_:)](corevideo/cvdisplaylinkisrunning(_:).md)
- [CVDisplayLinkGetTypeID()](corevideo/cvdisplaylinkgettypeid().md)