---
title: MEFormatReader
framework: MediaExtension
role: symbol
role_heading: Protocol
platforms: [macOS 14.0+]
path: mediaextension/meformatreader
---

# MEFormatReader

A protocol that defines the requirements for a format reader, which represents a single media asset.

## Declaration

```swift
protocol MEFormatReader : NSObjectProtocol
```

## Overview

Overview This protocol provides an interface for the Media Toolbox to interact with extension plug-in format readers, which provide information about media assets. MEFormatReader objects are always instantiated by the Media Toolbox. note: Developers who wish to build MediaExtension format readers using this API need to include a Format reader entitlement, provisioning profile, and specialized dictionary in their Info.plist file when building their extensions. For more information, see Entitlements, Create a development provisioning profile, and Format reader property list dictionaries. To create an MEFormatReader object, Media Toolbox first creates a primary MEByteSource object from a source media asset. It then creates an MEFormatReaderExtension object and calls its formatReader(with:options:) method. Once a user installs and runs the host app, embedded MediaExtension format reader extensions become available to any app on the user’s system that opts in to using them by calling MTRegisterProfessionalVideoWorkflowFormatReaders(). important: MEFormatReader objects run in a sandboxed process with restricted access to the filesystem, network, and other kernel resources.

## Topics

### Reading and parsing media assets

- [loadFileInfo(completionHandler:)](mediaextension/meformatreader/loadfileinfo(completionhandler:).md)
- [loadMetadata(completionHandler:)](mediaextension/meformatreader/loadmetadata(completionhandler:).md)
- [loadTrackReaders(completionHandler:)](mediaextension/meformatreader/loadtrackreaders(completionhandler:).md)
- [parseAdditionalFragments(completionHandler:)](mediaextension/meformatreader/parseadditionalfragments(completionhandler:).md)
- [MEFormatReaderParseAdditionalFragmentsStatus](mediaextension/meformatreaderparseadditionalfragmentsstatus.md)

### Extension requirements

- [Format reader property list dictionaries](mediaextension/format-reader-property-list-dictionaries.md)
- [Format reader entitlement](mediaextension/format-reader-entitlement.md)

## Relationships

### Inherits From

- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### Format readers

- [Supporting custom media formats and decoders](mediaextension/supporting-custom-media-formats-and-decoders.md)
- [MEFormatReaderExtension](mediaextension/meformatreaderextension.md)
- [MEFormatReaderInstantiationOptions](mediaextension/meformatreaderinstantiationoptions.md)
- [MEFileInfo](mediaextension/mefileinfo.md)
- [Format reader property list dictionaries](mediaextension/format-reader-property-list-dictionaries.md)
- [Format reader entitlement](mediaextension/format-reader-entitlement.md)