<!--
{
  "availability" : [

  ],
  "documentType" : "symbol",
  "framework" : "QuickTime File Format",
  "identifier" : "/documentation/quicktime-file-format/Track_input_map_atom",
  "metadataVersion" : "0.1.0",
  "role" : "Atom",
  "symbol" : {
    "kind" : "Atom",
    "modules" : [
      "QuickTime File Format"
    ],
    "preciseIdentifier" : "__docc_universal_symbol_reference_$Track_input_map_atom"
  },
  "title" : "Track input map atom ('imap')"
}
-->

# Track input map atom ('imap')

An atom that defines how data being sent to this track from its nonprimary sources is to be interpreted.

## Overview

This atom contains one or more track input atoms. Note that the track input map atom is a QT atom structure.

The layout of a track input map atom is as follows:

|Track input map atom                                                                               |Bytes   |
|---------------------------------------------------------------------------------------------------|--------|
|``doc://com.apple.qtff/documentation/quicktime-file-format/Track_input_map_atom/Size``             |4       |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Track_input_map_atom/Type`` = `'imap'`  |4       |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Track_input_map_atom/Track_input_atoms``|Variable|

## Topics

### Data fields

[`Size`](/documentation/quicktime-file-format/Track_input_map_atom/Size)

A 32-bit integer that specifies the number of bytes in this track input map atom.

[`Type`](/documentation/quicktime-file-format/Track_input_map_atom/Type)

A 32-bit integer that identifies the atom type.

[`Track input atoms`](/documentation/quicktime-file-format/Track_input_map_atom/Track_input_atoms)

A list of track input atoms specifying how to use the input data.


---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)