<!--
{
  "availability" : [

  ],
  "documentType" : "symbol",
  "framework" : "QuickTime File Format",
  "identifier" : "/documentation/quicktime-file-format/Version_check_atom",
  "metadataVersion" : "0.1.0",
  "role" : "Atom",
  "symbol" : {
    "kind" : "Atom",
    "modules" : [
      "QuickTime File Format"
    ],
    "preciseIdentifier" : "__docc_universal_symbol_reference_$Version_check_atom"
  },
  "title" : "Version check atom ('rmvc')"
}
-->

# Version check atom ('rmvc')

A version check atom specifies a software package, such as QuickTime or QuickTime VR, and the version of that package needed to display a movie.

## Overview

The package is specified using a
Macintosh Gestalt type, such a `'qtim'` for QuickTime (QuickTime provides support for these Gestalt tests in the Windows computing environment).
You can specify a minimum required version to be returned by the Gestalt check, or you can require that a specific value be returned after performing a binary AND operation on the
Gestalt bitfield and a mask.
Multiple version check atoms are allowed within a given reference movie descriptor atom. Applications should not attempt to play a movie unless all version checks are successful.

## Topics

### Data fields

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

The number of bytes in this version check atom.

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

The type of this atom.

[`Flags`](/documentation/quicktime-file-format/Version_check_atom/Flags)

A 32-bit integer.

[`Software package`](/documentation/quicktime-file-format/Version_check_atom/Software_package)

A 32-bit Gestalt type specifying the software package to check for.

[`Version`](/documentation/quicktime-file-format/Version_check_atom/Version)

An unsigned 32-bit integer containing either the minimum required version or the required value after a binary `AND` operation.

[`Mask`](/documentation/quicktime-file-format/Version_check_atom/Mask)

The mask for a binary `AND` operation on the Gestalt bitfield.

[`Check type`](/documentation/quicktime-file-format/Version_check_atom/Check_type)

The type of check to perform, expressed as 16-bit integer.


---

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)