# preservesDynamicHDRMetadata Indicates whether the receiver should preserve dynamic HDR metadata as an attachment on the output sample buffer’s underlying pixel buffer. ``` var preservesDynamicHDRMetadata: Bool { get set } ``` ## Discussion Set this property to `true` if you wish to use [`AVCaptureVideoDataOutput`](/documentation/AVFoundation/AVCaptureVideoDataOutput) with [`AVAssetWriter`](/documentation/AVFoundation/AVAssetWriter) to record HDR movies. You must also set `kVTCompressionPropertyKey_PreserveDynamicHDRMetadata` to `true` in the compression settings you pass to your [`AVAssetWriterInput`](/documentation/AVFoundation/AVAssetWriterInput). These compression settings are represented under the [`AVVideoCompressionPropertiesKey`](/documentation/AVFoundation/AVVideoCompressionPropertiesKey) sub-dictionary of your top-level AVVideoSettings (see ). When you set this key to `true`, performance improves, as the encoder is able to skip HDR metadata calculation for every frame. The default value is `false`. --- Copyright © 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)