---
title: kVTCompressionPropertyKey_MaxFrameDelayCount
framework: videotoolbox
role: symbol
role_heading: Global Variable
path: videotoolbox/kvtcompressionpropertykey_maxframedelaycount
---

# kVTCompressionPropertyKey_MaxFrameDelayCount

The maximum number of frames that a compressor is allowed to hold before it must output a compressed frame.

## Declaration

```swift
let kVTCompressionPropertyKey_MaxFrameDelayCount: CFString
```

## Discussion

Discussion This value limits the number of frames that may be held in the compression window. If the maximum frame delay count is M, then before the call to encode frame N returns, frame N-M must have been emitted. The default is kVTUnlimitedFrameDelayCount, which sets no limit on the compression window.

## Topics

### Delay Counts

- [kVTUnlimitedFrameDelayCount](videotoolbox/kvtunlimitedframedelaycount.md)

## See Also

### Runtime Restrictions

- [kVTCompressionPropertyKey_MaxH264SliceBytes](videotoolbox/kvtcompressionpropertykey_maxh264slicebytes.md)
- [kVTCompressionPropertyKey_MaximizePowerEfficiency](videotoolbox/kvtcompressionpropertykey_maximizepowerefficiency.md)
- [kVTCompressionPropertyKey_RealTime](videotoolbox/kvtcompressionpropertykey_realtime.md)