---
title: Format Description Constants
framework: coremedia
role: collectionGroup
role_heading: API Collection
path: coremedia/format-description-constants
---

# Format Description Constants

Constants that identify format descriptions.

## Topics

### Description Constants

- [kCMFormatDescriptionAlphaChannelMode_PremultipliedAlpha](coremedia/kcmformatdescriptionalphachannelmode_premultipliedalpha.md)
- [kCMFormatDescriptionAlphaChannelMode_StraightAlpha](coremedia/kcmformatdescriptionalphachannelmode_straightalpha.md)
- [kCMFormatDescriptionTransferFunction_ITU_R_2100_HLG](coremedia/kcmformatdescriptiontransferfunction_itu_r_2100_hlg.md)
- [kCMFormatDescriptionTransferFunction_Linear](coremedia/kcmformatdescriptiontransferfunction_linear.md)
- [kCMFormatDescriptionTransferFunction_SMPTE_ST_2084_PQ](coremedia/kcmformatdescriptiontransferfunction_smpte_st_2084_pq.md)
- [kCMFormatDescriptionTransferFunction_sRGB](coremedia/kcmformatdescriptiontransferfunction_srgb.md)

### Description Extension Keys

- [kCMFormatDescriptionExtensionKey_MetadataKeyTable](coremedia/kcmformatdescriptionextensionkey_metadatakeytable.md)

### Description Extension Constants

- [kCMFormatDescriptionExtension_AlphaChannelMode](coremedia/kcmformatdescriptionextension_alphachannelmode.md)
- [kCMFormatDescriptionExtension_AlternativeTransferCharacteristics](coremedia/kcmformatdescriptionextension_alternativetransfercharacteristics.md)
- [kCMFormatDescriptionExtension_AmbientViewingEnvironment](coremedia/kcmformatdescriptionextension_ambientviewingenvironment.md)
- [kCMFormatDescriptionExtension_AuxiliaryTypeInfo](coremedia/kcmformatdescriptionextension_auxiliarytypeinfo.md)
- [kCMFormatDescriptionExtension_BitsPerComponent](coremedia/kcmformatdescriptionextension_bitspercomponent.md)
- [kCMFormatDescriptionExtension_BytesPerRow](coremedia/kcmformatdescriptionextension_bytesperrow.md)
- [kCMFormatDescriptionExtension_ChromaLocationBottomField](coremedia/kcmformatdescriptionextension_chromalocationbottomfield-swift.var.md)
- [kCMFormatDescriptionExtension_ChromaLocationTopField](coremedia/kcmformatdescriptionextension_chromalocationtopfield-swift.var.md)
- [kCMFormatDescriptionExtension_CleanAperture](coremedia/kcmformatdescriptionextension_cleanaperture-swift.var.md)
- [kCMFormatDescriptionExtension_ColorPrimaries](coremedia/kcmformatdescriptionextension_colorprimaries-swift.var.md)
- [kCMFormatDescriptionExtension_ContainsAlphaChannel](coremedia/kcmformatdescriptionextension_containsalphachannel.md)
- [kCMFormatDescriptionExtension_ContentLightLevelInfo](coremedia/kcmformatdescriptionextension_contentlightlevelinfo.md)
- [kCMFormatDescriptionExtension_Depth](coremedia/kcmformatdescriptionextension_depth.md)
- [kCMFormatDescriptionExtension_FieldCount](coremedia/kcmformatdescriptionextension_fieldcount-swift.var.md)
- [kCMFormatDescriptionExtension_FieldDetail](coremedia/kcmformatdescriptionextension_fielddetail-swift.var.md)
- [kCMFormatDescriptionExtension_FormatName](coremedia/kcmformatdescriptionextension_formatname.md)
- [kCMFormatDescriptionExtension_FullRangeVideo](coremedia/kcmformatdescriptionextension_fullrangevideo.md)
- [kCMFormatDescriptionExtension_GammaLevel](coremedia/kcmformatdescriptionextension_gammalevel-swift.var.md)
- [kCMFormatDescriptionExtension_HorizontalFieldOfView](coremedia/kcmformatdescriptionextension_horizontalfieldofview.md)
- [kCMFormatDescriptionExtension_ICCProfile](coremedia/kcmformatdescriptionextension_iccprofile.md)
- [kCMFormatDescriptionExtension_MasteringDisplayColorVolume](coremedia/kcmformatdescriptionextension_masteringdisplaycolorvolume.md)
- [kCMFormatDescriptionExtension_OriginalCompressionSettings](coremedia/kcmformatdescriptionextension_originalcompressionsettings.md)
- [kCMFormatDescriptionExtension_PixelAspectRatio](coremedia/kcmformatdescriptionextension_pixelaspectratio-swift.var.md)
- [kCMFormatDescriptionExtension_ProtectedContentOriginalFormat](coremedia/kcmformatdescriptionextension_protectedcontentoriginalformat.md)
- [kCMFormatDescriptionExtension_SampleDescriptionExtensionAtoms](coremedia/kcmformatdescriptionextension_sampledescriptionextensionatoms.md)
- [kCMFormatDescriptionExtension_TransferFunction](coremedia/kcmformatdescriptionextension_transferfunction-swift.var.md)
- [kCMFormatDescriptionExtension_VerbatimISOSampleEntry](coremedia/kcmformatdescriptionextension_verbatimisosampleentry.md)
- [kCMFormatDescriptionExtension_VerbatimImageDescription](coremedia/kcmformatdescriptionextension_verbatimimagedescription-swift.var.md)
- [kCMFormatDescriptionExtension_VerbatimSampleDescription](coremedia/kcmformatdescriptionextension_verbatimsampledescription.md)
- [kCMFormatDescriptionExtension_YCbCrMatrix](coremedia/kcmformatdescriptionextension_ycbcrmatrix-swift.var.md)

## See Also

### Constants

- [Audio Format Description Mask Codes](coremedia/audio-format-desc-codes.md)
- [Chroma Location Extension Constants](coremedia/chroma-location-extension-constants.md)
- [Clean Aperture Extension Constants](coremedia/clean-aperture-extension-constants.md)
- [Closed Caption Format Type Constants](coremedia/closed-caption-formats.md)
- [Color Primary Extension Constants](coremedia/color-primary-extension-constants.md)
- [Field Detail Extension Constants](coremedia/field-detail-extension-constants.md)
- [Format Description Bridge Error Codes](coremedia/format-description-bridge-errors.md)
- [Format Description Error Codes](coremedia/format-description-errors.md)
- [HEVC Temporal Level Info Constants](coremedia/hevc-temporal-level-info-constants.md)
- [Metadata Format Description Constants](coremedia/metadata-format-description-constants.md)
- [MPEG-2-conformant Formats](coremedia/mpeg-2-conformant-formats.md)
- [Pixel Aspect Ratio Extension Constants](coremedia/pixel-aspect-ratio-extension-constants.md)
- [Text Display Flags](coremedia/text-display-flags.md)
- [Text Format Constants](coremedia/text-format-constants.md)
- [Text Format Description Constants](coremedia/text-format-description-constants.md)