---
title: kVTCompressionPropertyKey_NumberOfPendingFrames
framework: videotoolbox
role: symbol
role_heading: Global Variable
path: videotoolbox/kvtcompressionpropertykey_numberofpendingframes
---

# kVTCompressionPropertyKey_NumberOfPendingFrames

The number of pending frames in the compression session.

## Declaration

```swift
let kVTCompressionPropertyKey_NumberOfPendingFrames: CFString
```

## Discussion

Discussion This number may decrease asynchronously.

## See Also

### Buffers

- [kVTCompressionPropertyKey_PixelBufferPoolIsShared](videotoolbox/kvtcompressionpropertykey_pixelbufferpoolisshared.md)
- [kVTCompressionPropertyKey_VideoEncoderPixelBufferAttributes](videotoolbox/kvtcompressionpropertykey_videoencoderpixelbufferattributes.md)