---
title: CMBlockBufferAttachmentKeyDefinitions
framework: coremedia
role: symbol
role_heading: Enumeration
path: coremedia/cmblockbufferattachmentkeydefinitions
---

# CMBlockBufferAttachmentKeyDefinitions

A namespace for block buffer attachment keys.

## Declaration

```swift
enum CMBlockBufferAttachmentKeyDefinitions
```

## Relationships

### Conforms To

- [CVAttachmentKeyDefinitions](corevideo/cvattachmentkeydefinitions.md)