---
title: Creating an effect description
framework: quicktime-file-format
role: collectionGroup
path: quicktime-file-format/creating_an_effect_description
---

# Creating an effect description

Tell QuickTime which effect to execute and control how the effect behaves at runtime with an effect description.

## Overview

Overview An effect description tells QuickTime which effect to execute and contains the parameters that control how the effect behaves at runtime. You create an effect description by creating an atom container, inserting a QT atom that specifies the effect, and inserting a set of QT atoms that set its parameters. There are support functions you can call to assist you in this process. QTCreateStandardParameterDialog returns a complete effect description that you can use, including user-selected settings; you only need to add kEffectSourceName atoms to the description for effects that require sources. At a lower level, QTGetEffectsList returns a list of the available effects and ImageCodecGetParameterList will return a description of the parameters for an effect, including the default value for each parameter in the form of a QT atom that can be inserted directly into an effect description.

## Topics

### Effect descriptions

- [Structure of an effect description](quicktime-file-format/structure_of_an_effect_description.md)
- [Required atoms of an effects description](quicktime-file-format/required_atoms_of_an_effects_description.md)
- [Parameter atoms of an effects description](quicktime-file-format/parameter_atoms_of_an_effects_description.md)
- [Creating an input map](quicktime-file-format/creating_an_input_map.md)

## See Also

### Movie features

- [Preparing sound and subtitle alternate groups for use with Apple devices](quicktime-file-format/preparing_sound_and_subtitle_alternate_groups_for_use_with_apple_devices.md)