---
title: CMFormatDescription.EqualityMask
framework: coremedia
role: symbol
role_heading: Structure
path: coremedia/cmformatdescription/equalitymask
---

# CMFormatDescription.EqualityMask

A type that describes format description equality masks.

## Declaration

```swift
struct EqualityMask
```

## Topics

### Equality Masks

- [all](coremedia/cmformatdescription/equalitymask/all.md)
- [channelLayout](coremedia/cmformatdescription/equalitymask/channellayout.md)
- [extensions](coremedia/cmformatdescription/equalitymask/extensions.md)
- [magicCookie](coremedia/cmformatdescription/equalitymask/magiccookie.md)
- [streamBasicDescription](coremedia/cmformatdescription/equalitymask/streambasicdescription.md)

## Relationships

### Conforms To

- [Equatable](swift/equatable.md)
- [ExpressibleByArrayLiteral](swift/expressiblebyarrayliteral.md)
- [OptionSet](swift/optionset.md)
- [RawRepresentable](swift/rawrepresentable.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)
- [SetAlgebra](swift/setalgebra.md)

## See Also

### Constants

- [extensionKeysCommonWithImageBuffers](coremedia/cmformatdescription/extensionkeyscommonwithimagebuffers.md)
- [typeID](coremedia/cmformatdescription/typeid.md)
- [CMFormatDescription.MediaType](coremedia/cmformatdescription/mediatype-swift.struct.md)
- [CMFormatDescription.MediaSubType](coremedia/cmformatdescription/mediasubtype-swift.struct.md)
- [CMFormatDescription.TimeCode](coremedia/cmformatdescription/timecode.md)
- [CMFormatDescription.Extensions](coremedia/cmformatdescription/extensions-swift.struct.md)
- [CMFormatDescription.ParameterSetCollection](coremedia/cmformatdescription/parametersetcollection.md)