---
title: kVTEncodeFrameOptionKey_ForceLTRRefresh
framework: videotoolbox
role: symbol
role_heading: Global Variable
path: videotoolbox/kvtencodeframeoptionkey_forceltrrefresh
---

# kVTEncodeFrameOptionKey_ForceLTRRefresh

A Boolean value that indicates whether to force Long Term Reference (LTR).

## Declaration

```swift
let kVTEncodeFrameOptionKey_ForceLTRRefresh: CFString
```

## See Also

### Long-Term Reference

- [kVTCompressionPropertyKey_EnableLTR](videotoolbox/kvtcompressionpropertykey_enableltr.md)
- [kVTEncodeFrameOptionKey_AcknowledgedLTRTokens](videotoolbox/kvtencodeframeoptionkey_acknowledgedltrtokens.md)
- [kVTSampleAttachmentKey_RequireLTRAcknowledgementToken](videotoolbox/kvtsampleattachmentkey_requireltracknowledgementtoken.md)