---
title: kVTCompressionPropertyKey_RecommendedParallelizationLimit
framework: videotoolbox
role: symbol
role_heading: Global Variable
path: videotoolbox/kvtcompressionpropertykey_recommendedparallelizationlimit
---

# kVTCompressionPropertyKey_RecommendedParallelizationLimit

The recommended number of compression sessions to instantiate in a parallel encoding configuration.

## Declaration

```swift
let kVTCompressionPropertyKey_RecommendedParallelizationLimit: CFString
```

## Discussion

Discussion Configuring a compression session for parallel encoding requires the use of the kVTCompressionPropertyKey_MoreFramesBeforeStart, kVTCompressionPropertyKey_MoreFramesAfterEnd, and kVTCompressionPropertyKey_SourceFrameCount properties. For example, if the recommended parallelization limit is 4, a setup for 4 compression sessions for a 400 frame movie might look like the following:

## See Also

### Parallelization

- [kVTCompressionPropertyKey_RecommendedParallelizedSubdivisionMinimumDuration](videotoolbox/kvtcompressionpropertykey_recommendedparallelizedsubdivisionminimumduration.md)
- [kVTCompressionPropertyKey_RecommendedParallelizedSubdivisionMinimumFrameCount](videotoolbox/kvtcompressionpropertykey_recommendedparallelizedsubdivisionminimumframecount.md)