---
title: kCMSampleAttachmentKey_PartialSync
framework: coremedia
role: symbol
role_heading: Global Variable
path: coremedia/kcmsampleattachmentkey_partialsync
---

# kCMSampleAttachmentKey_PartialSync

Indicates whether the sample is a partial sync sample (type CFBoolean, default false).

## Declaration

```swift
let kCMSampleAttachmentKey_PartialSync: CFString
```

## Discussion

Discussion A partial sync sample can be decoded without requiring any previous samples to have been decoded. Samples following two consecutive partial sync samples also do not require samples prior to the pair to have been decoded. To treat a sample as a partial sync sample, set a value of kCFBooleanTrue for both this key and the kCMSampleAttachmentKey_NotSync key. This attachment is read from and written to media files.

## See Also

### Sample Keys

- [kCMSampleAttachmentKey_NotSync](coremedia/kcmsampleattachmentkey_notsync.md)
- [kCMSampleAttachmentKey_DependsOnOthers](coremedia/kcmsampleattachmentkey_dependsonothers.md)
- [kCMSampleAttachmentKey_IsDependedOnByOthers](coremedia/kcmsampleattachmentkey_isdependedonbyothers.md)
- [kCMSampleAttachmentKey_DisplayImmediately](coremedia/kcmsampleattachmentkey_displayimmediately.md)
- [kCMSampleAttachmentKey_DoNotDisplay](coremedia/kcmsampleattachmentkey_donotdisplay.md)
- [kCMSampleAttachmentKey_EarlierDisplayTimesAllowed](coremedia/kcmsampleattachmentkey_earlierdisplaytimesallowed.md)
- [kCMSampleAttachmentKey_HasRedundantCoding](coremedia/kcmsampleattachmentkey_hasredundantcoding.md)
- [kCMSampleAttachmentKey_PostDecodeProcessingMetadata](coremedia/kcmsampleattachmentkey_postdecodeprocessingmetadata.md)