---
title: nominalFrameRate
framework: MediaExtension
role: symbol
role_heading: Instance Property
platforms: [macOS 14.0+]
path: mediaextension/metrackinfo/nominalframerate
---

# nominalFrameRate

The frame rate of the track in frames per second, as a 32-bit floating point number.

## Declaration

```swift
var nominalFrameRate: Float32 { get set }
```

## Discussion

Discussion For field-based video tracks that carry one field per media sample, the value of this property is the field rate, not the frame rate. MediaToolbox uses this property to calculate the maximum playback speed.

## See Also

### Inspecting track information

- [mediaType](mediaextension/metrackinfo/mediatype.md)
- [trackID](mediaextension/metrackinfo/trackid.md)
- [isEnabled](mediaextension/metrackinfo/isenabled.md)
- [naturalTimescale](mediaextension/metrackinfo/naturaltimescale.md)
- [extendedLanguageTag](mediaextension/metrackinfo/extendedlanguagetag.md)
- [naturalSize](mediaextension/metrackinfo/naturalsize.md)
- [preferredTransform](mediaextension/metrackinfo/preferredtransform.md)
- [requiresFrameReordering](mediaextension/metrackinfo/requiresframereordering.md)