<!--
{
  "documentType" : "article",
  "framework" : "Quartz",
  "identifier" : "/documentation/Quartz/standard-protocol-input-keys",
  "metadataVersion" : "0.1.0",
  "role" : "collectionGroup",
  "title" : "Standard Protocol Input Keys"
}
-->

# Standard Protocol Input Keys

Input ports of a composition.

## Topics

### Constants

[`QCCompositionInputImageKey`](/documentation/Quartz/QCCompositionInputImageKey)

An image input port whose key is  `inputImage`.

[`QCCompositionInputSourceImageKey`](/documentation/Quartz/QCCompositionInputSourceImageKey)

An  image input port whose key is `inputSourceImage`.

[`QCCompositionInputDestinationImageKey`](/documentation/Quartz/QCCompositionInputDestinationImageKey)

An image input port whose key is `inputDestinationImage`.

[`QCCompositionInputRSSFeedURLKey`](/documentation/Quartz/QCCompositionInputRSSFeedURLKey)

A string input port whose key is `inputRSSFeedURL`. This port must be passed an http or feed scheme URL.

[`QCCompositionInputRSSArticleDurationKey`](/documentation/Quartz/QCCompositionInputRSSArticleDurationKey)

A number input port whose key is `inputRSSArticleDuration`. The value must be expressed in seconds.

[`QCCompositionInputPreviewModeKey`](/documentation/Quartz/QCCompositionInputPreviewModeKey)

A Boolean input port whose key is `inputPreviewMode`. When the value of this input port is set to `TRUE`, the composition that provides this port must be able to run in a low-quality mode that produces a preview of the composition.

[`QCCompositionInputXKey`](/documentation/Quartz/QCCompositionInputXKey)

A number input port whose key is `inputX`. The value must be normalized to the image width with the origin on the left.

[`QCCompositionInputYKey`](/documentation/Quartz/QCCompositionInputYKey)

A number input port whose key is `inputY`. The value must be normalized to the image height with the origin at the bottom.

[`QCCompositionInputScreenImageKey`](/documentation/Quartz/QCCompositionInputScreenImageKey)

An image input port whose key is `inputScreenImage`.

[`QCCompositionInputAudioPeakKey`](/documentation/Quartz/QCCompositionInputAudioPeakKey)

A number input port whose key is `inputAudioPeak`. The value must be in the `[0,1]` range as a mono signal with no decay applied.

[`QCCompositionInputAudioSpectrumKey`](/documentation/Quartz/QCCompositionInputAudioSpectrumKey)

A structure input port whose key is `inputAudioSpectrum`. The structure must contain 16 values in the `[0,1]` range representing 16 spectrum bands of the mono signal from low to high frequencies with no decay applied.

[`QCCompositionInputTrackPositionKey`](/documentation/Quartz/QCCompositionInputTrackPositionKey)

A number input port whose key is `inputTrackPosition`. The value must be expressed in seconds.

[`QCCompositionInputTrackInfoKey`](/documentation/Quartz/QCCompositionInputTrackInfoKey)

A structure input port whose key is `inputTrackInfo`. The structure contains optional entries, such as “name”, “artist”, “album”, “duration”, “artwork”, and so on.

[`QCCompositionInputTrackSignalKey`](/documentation/Quartz/QCCompositionInputTrackSignalKey)

A Boolean input port whose key is `inputTrackSignal`.

[`QCCompositionInputPrimaryColorKey`](/documentation/Quartz/QCCompositionInputPrimaryColorKey)

A color input port whose key is `inputPrimaryColor`.

[`QCCompositionInputSecondaryColorKey`](/documentation/Quartz/QCCompositionInputSecondaryColorKey)

A color input port whose key is `inputSecondaryColor`.

[`QCCompositionInputPaceKey`](/documentation/Quartz/QCCompositionInputPaceKey)

A number input port whose key is `inputPace`. The value must be in the `[0,1]` range.


---

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)