---
title: "Reference movie descriptor atom ('rmda')"
framework: quicktime-file-format
role: symbol
role_heading: Atom
path: quicktime-file-format/reference_movie_descriptor_atom
---

# Reference movie descriptor atom ('rmda')

An atom that contains other atoms that describe where to find a particular movie, the system requirements to play that movie, and a quality rating.

## Overview

Overview The reference movie descriptor atom contains other atoms that describe where a particular movie can be found, and optionally what the system requirements are to play that movie, as well as an optional quality rating for that movie. A reference movie descriptor atom’s parent is always a movie reference atom ('rmra'). Multiple reference movie descriptor atoms are allowed in a given movie reference atom, and more than one is usually present.

## Topics

### Data fields

- [Size](quicktime-file-format/reference_movie_descriptor_atom/size.md)
- [Type](quicktime-file-format/reference_movie_descriptor_atom/type.md)
- [Data reference atom](quicktime-file-format/reference_movie_descriptor_atom/data_reference_atom.md)
- [Data rate atom](quicktime-file-format/reference_movie_descriptor_atom/data_rate_atom.md)
- [CPU speed atom](quicktime-file-format/reference_movie_descriptor_atom/cpu_speed_atom.md)
- [Version check atom](quicktime-file-format/reference_movie_descriptor_atom/version_check_atom.md)
- [Component detect atom](quicktime-file-format/reference_movie_descriptor_atom/component_detect_atom.md)
- [Quality atom](quicktime-file-format/reference_movie_descriptor_atom/quality_atom.md)

## See Also

### Describing reference movies

- [Reference movie atom ('rmra')](quicktime-file-format/reference_movie_atom.md)
- [Data reference atom](quicktime-file-format/reference_movie_data_reference_atom.md)
- [Data rate atom ('rmdr')](quicktime-file-format/data_rate_atom.md)
- [CPU speed atom ('rmcs')](quicktime-file-format/cpu_speed_atom.md)
- [Version check atom ('rmvc')](quicktime-file-format/version_check_atom.md)
- [Component detect atom ('rmcd')](quicktime-file-format/component_detect_atom.md)
- [Movie importer component flags](quicktime-file-format/movie_importer_component_flags.md)
- [Quality atom ('rmqu')](quicktime-file-format/quality_atom.md)