---
title: hevcSyncSampleNALUnitType
framework: coremedia
role: symbol
role_heading: Instance Property
path: coremedia/cmsamplebuffer/sampleattachments-swift.struct/hevcsyncsamplenalunittype
---

# hevcSyncSampleNALUnitType

Indicates sync sample NAL unit type.

## Declaration

```swift
var hevcSyncSampleNALUnitType: Int? { get set }
```

## Discussion

Discussion Corresponds to ‘sync’ sample group. This attachment is read from and written to media files as specified in ISO/IEC 14496-15 section 8.4.4 Sync sample sample grouping.