---
title: AVMutableMetadataItem
framework: avfoundation
role: symbol
role_heading: Class
path: avfoundation/avmutablemetadataitem
---

# AVMutableMetadataItem

A mutable metadata item for an audiovisual asset or for one of its tracks.

## Declaration

```swift
class AVMutableMetadataItem
```

## Overview

Overview You can initialize a mutable metadata item from an existing AVMetadataItem object or with a one or more of the basic properties of a metadata item: a key, a key space, a locale, and a value.

## Topics

### Identifying metadata items

- [identifier](avfoundation/avmutablemetadataitem/identifier.md)

### Accessing keys and key spaces

- [key](avfoundation/avmutablemetadataitem/key.md)
- [keySpace](avfoundation/avmutablemetadataitem/keyspace.md)

### Accessing values

- [value](avfoundation/avmutablemetadataitem/value.md)
- [extraAttributes](avfoundation/avmutablemetadataitem/extraattributes.md)
- [dataType](avfoundation/avmutablemetadataitem/datatype.md)
- [stringValue](avfoundation/avmutablemetadataitem/stringvalue.md)
- [numberValue](avfoundation/avmutablemetadataitem/numbervalue.md)
- [dateValue](avfoundation/avmutablemetadataitem/datevalue.md)
- [dataValue](avfoundation/avmutablemetadataitem/datavalue.md)

### Accessing timing

- [time](avfoundation/avmutablemetadataitem/time.md)
- [startDate](avfoundation/avmutablemetadataitem/startdate.md)
- [duration](avfoundation/avmutablemetadataitem/duration.md)

### Accessing language support

- [locale](avfoundation/avmutablemetadataitem/locale.md)
- [extendedLanguageTag](avfoundation/avmutablemetadataitem/extendedlanguagetag.md)

## Relationships

### Inherits From

- [AVMetadataItem](avfoundation/avmetadataitem.md)

### Conforms To

- [AVAsynchronousKeyValueLoading](avfoundation/avasynchronouskeyvalueloading.md)
- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSCopying](foundation/nscopying.md)
- [NSMutableCopying](foundation/nsmutablecopying.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### Metadata

- [Retrieving media metadata](avfoundation/retrieving-media-metadata.md)
- [AVMetadataItem](avfoundation/avmetadataitem.md)
- [AVMetadataIdentifier](avfoundation/avmetadataidentifier.md)
- [AVMetadataKey](avfoundation/avmetadatakey.md)
- [AVMetadataKeySpace](avfoundation/avmetadatakeyspace.md)
- [AVMetadataExtraAttributeKey](avfoundation/avmetadataextraattributekey.md)
- [AVMetadataFormat](avfoundation/avmetadataformat.md)
- [AVMetadataItemFilter](avfoundation/avmetadataitemfilter.md)