CMFormatDescription

Overview

CMFormatDescriptions are immutable Core Foundation objects that describe media data of various types, including audio, video, and muxed media data. There are two types of API: media-type-agnostic APIs (supported by all CMFormatDescriptions) and media-type-specific APIs. The media-type-agnostic APIs are prefixed with CMFormatDescription, and the media-type-specific APIs are prefixed with CMAudioFormatDescription, CMVideoFormatDescription, and so on.

Topics

Creating Format Descriptions

• CMFormatDescriptionCreate(allocator:mediaType:mediaSubType:extensions:formatDescriptionOut:)

Comparing Format Descriptions

• CMFormatDescriptionEqual(_:otherFormatDescription:)
• CMFormatDescriptionEqualIgnoringExtensionKeys(_:otherFormatDescription:extensionKeysToIgnore:sampleDescriptionExtensionAtomKeysToIgnore:)

Inspecting Format Descriptions

• CMFormatDescriptionGetMediaType(_:)
• CMFormatDescriptionGetMediaSubType(_:)
• CMFormatDescriptionGetExtension(_:extensionKey:)
• CMFormatDescriptionGetExtensions(_:)
• CMFormatDescriptionGetTypeID()

Working with Audio Descriptions

• CMSoundDescriptionFlavor
• CMAudioFormatDescriptionCreateSummary(allocator:formatDescriptionArray:flags:formatDescriptionOut:)
• CMAudioFormatDescriptionCreate(allocator:asbd:layoutSize:layout:magicCookieSize:magicCookie:extensions:formatDescriptionOut:)
• CMAudioFormatDescriptionEqual(_:otherFormatDescription:equalityMask:equalityMaskOut:)
• CMAudioFormatDescriptionGetChannelLayout(_:sizeOut:)
• CMAudioFormatDescriptionGetFormatList(_:sizeOut:)
• CMAudioFormatDescriptionGetMagicCookie(_:sizeOut:)
• CMAudioFormatDescriptionGetMostCompatibleFormat(_:)
• CMAudioFormatDescriptionGetRichestDecodableFormat(_:)
• CMAudioFormatDescriptionGetStreamBasicDescription(_:)
• CMDoesBigEndianSoundDescriptionRequireLegacyCBRSampleTableLayout(_:flavor:)
• CMSwapBigEndianSoundDescriptionToHost(_:_:)
• CMSwapHostEndianSoundDescriptionToBig(_:_:)
• CMAudioFormatDescriptionCreateFromBigEndianSoundDescriptionData(allocator:bigEndianSoundDescriptionData:size:flavor:formatDescriptionOut:)
• CMAudioFormatDescriptionCreateFromBigEndianSoundDescriptionBlockBuffer(allocator:bigEndianSoundDescriptionBlockBuffer:flavor:formatDescriptionOut:)
• CMAudioFormatDescriptionCopyAsBigEndianSoundDescriptionBlockBuffer(allocator:audioFormatDescription:flavor:blockBufferOut:)

Working with Video Descriptions

• CMImageDescriptionFlavor
• CMVideoFormatDescriptionCreate(allocator:codecType:width:height:extensions:formatDescriptionOut:)
• CMVideoFormatDescriptionCreateForImageBuffer(allocator:imageBuffer:formatDescriptionOut:)
• CMVideoFormatDescriptionGetCleanAperture(_:originIsAtTopLeft:)
• CMVideoFormatDescriptionGetDimensions(_:)
• CMVideoFormatDescriptionGetExtensionKeysCommonWithImageBuffers()
• CMVideoFormatDescriptionGetPresentationDimensions(_:usePixelAspectRatio:useCleanAperture:)
• CMVideoFormatDescriptionMatchesImageBuffer(_:imageBuffer:)
• CMVideoFormatDescriptionCreateFromH264ParameterSets(allocator:parameterSetCount:parameterSetPointers:parameterSetSizes:nalUnitHeaderLength:formatDescriptionOut:)
• CMVideoFormatDescriptionCreateFromHEVCParameterSets(allocator:parameterSetCount:parameterSetPointers:parameterSetSizes:nalUnitHeaderLength:extensions:formatDescriptionOut:)
• CMVideoFormatDescriptionGetH264ParameterSetAtIndex(_:parameterSetIndex:parameterSetPointerOut:parameterSetSizeOut:parameterSetCountOut:nalUnitHeaderLengthOut:)
• CMVideoFormatDescriptionCopyAsBigEndianImageDescriptionBlockBuffer(allocator:videoFormatDescription:stringEncoding:flavor:blockBufferOut:)
• CMVideoFormatDescriptionCreateFromBigEndianImageDescriptionBlockBuffer(allocator:bigEndianImageDescriptionBlockBuffer:stringEncoding:flavor:formatDescriptionOut:)
• CMVideoFormatDescriptionCreateFromBigEndianImageDescriptionData(allocator:bigEndianImageDescriptionData:size:stringEncoding:flavor:formatDescriptionOut:)
• CMSwapBigEndianImageDescriptionToHost(_:_:)
• CMSwapHostEndianImageDescriptionToBig(_:_:)

Working with Muxed Descriptions

• CMMuxedFormatDescriptionCreate(allocator:muxType:extensions:formatDescriptionOut:)

Working with Metadata Descriptions

• CMMetadataDescriptionFlavor
• CMMetadataFormatDescriptionCreateWithKeys(allocator:metadataType:keys:formatDescriptionOut:)
• CMMetadataFormatDescriptionGetKeyWithLocalID(_:localKeyID:)
• CMMetadataFormatDescriptionCopyAsBigEndianMetadataDescriptionBlockBuffer(allocator:metadataFormatDescription:flavor:blockBufferOut:)
• CMMetadataFormatDescriptionCreateByMergingMetadataFormatDescriptions(allocator:sourceDescription:otherSourceDescription:formatDescriptionOut:)
• CMMetadataFormatDescriptionCreateFromBigEndianMetadataDescriptionBlockBuffer(allocator:bigEndianMetadataDescriptionBlockBuffer:flavor:formatDescriptionOut:)
• CMMetadataFormatDescriptionCreateFromBigEndianMetadataDescriptionData(allocator:bigEndianMetadataDescriptionData:size:flavor:formatDescriptionOut:)
• CMMetadataFormatDescriptionCreateWithMetadataFormatDescriptionAndMetadataSpecifications(allocator:sourceDescription:metadataSpecifications:formatDescriptionOut:)
• CMMetadataFormatDescriptionCreateWithMetadataSpecifications(allocator:metadataType:metadataSpecifications:formatDescriptionOut:)
• CMSwapBigEndianMetadataDescriptionToHost(_:_:)
• CMSwapHostEndianMetadataDescriptionToBig(_:_:)
• CMMetadataFormatDescriptionGetIdentifiers(_:)

Working with Text Descriptions

• CMTextDescriptionFlavor
• CMTextFormatDescriptionGetDefaultStyle(_:localFontIDOut:boldOut:italicOut:underlineOut:fontSizeOut:colorComponentsOut:)
• CMTextFormatDescriptionGetDefaultTextBox(_:originIsAtTopLeft:heightOfTextTrack:defaultTextBoxOut:)
• CMTextFormatDescriptionGetDisplayFlags(_:displayFlagsOut:)
• CMTextFormatDescriptionGetFontName(_:localFontID:fontNameOut:)
• CMTextFormatDescriptionGetJustification(_:horizontalOut:verticalOut:)
• CMTextFormatDescriptionCopyAsBigEndianTextDescriptionBlockBuffer(allocator:textFormatDescription:flavor:blockBufferOut:)
• CMTextFormatDescriptionCreateFromBigEndianTextDescriptionBlockBuffer(allocator:bigEndianTextDescriptionBlockBuffer:flavor:mediaType:formatDescriptionOut:)
• CMTextFormatDescriptionCreateFromBigEndianTextDescriptionData(allocator:bigEndianTextDescriptionData:size:flavor:mediaType:formatDescriptionOut:)
• CMSwapBigEndianTextDescriptionToHost(_:_:)
• CMSwapHostEndianTextDescriptionToBig(_:_:)

Working with Time Code Descriptions

• CMTimeCodeDescriptionFlavor
• CMTimeCodeFormatDescriptionCreate(allocator:timeCodeFormatType:frameDuration:frameQuanta:flags:extensions:formatDescriptionOut:)
• CMTimeCodeFormatDescriptionGetFrameDuration(_:)
• CMTimeCodeFormatDescriptionGetFrameQuanta(_:)
• CMTimeCodeFormatDescriptionGetTimeCodeFlags(_:)
• CMTimeCodeFormatDescriptionCopyAsBigEndianTimeCodeDescriptionBlockBuffer(allocator:timeCodeFormatDescription:flavor:blockBufferOut:)
• CMTimeCodeFormatDescriptionCreateFromBigEndianTimeCodeDescriptionBlockBuffer(allocator:bigEndianTimeCodeDescriptionBlockBuffer:flavor:formatDescriptionOut:)
• CMTimeCodeFormatDescriptionCreateFromBigEndianTimeCodeDescriptionData(allocator:bigEndianTimeCodeDescriptionData:size:flavor:formatDescriptionOut:)
• CMSwapBigEndianTimeCodeDescriptionToHost(_:_:)
• CMSwapHostEndianTimeCodeDescriptionToBig(_:_:)

Working with Closed Captioning Descriptions

• CMClosedCaptionDescriptionFlavor
• CMClosedCaptionFormatDescriptionCopyAsBigEndianClosedCaptionDescriptionBlockBuffer(allocator:closedCaptionFormatDescription:flavor:blockBufferOut:)
• CMClosedCaptionFormatDescriptionCreateFromBigEndianClosedCaptionDescriptionBlockBuffer(allocator:bigEndianClosedCaptionDescriptionBlockBuffer:flavor:formatDescriptionOut:)
• CMClosedCaptionFormatDescriptionCreateFromBigEndianClosedCaptionDescriptionData(allocator:bigEndianClosedCaptionDescriptionData:size:flavor:formatDescriptionOut:)
• CMSwapHostEndianClosedCaptionDescriptionToBig(_:_:)
• CMSwapBigEndianClosedCaptionDescriptionToHost(_:_:)

Format Description Types

• CMFormatDescription
• CMAudioFormatDescription
• CMClosedCaptionFormatDescription
• CMMetadataFormatDescription
• CMMuxedFormatDescription
• CMTextFormatDescription
• CMTimeCodeFormatDescription
• CMVideoFormatDescription

Format Description Extension Keys

• kCMFormatDescriptionExtension_ContentColorVolume
• kCMFormatDescriptionExtension_HasAdditionalViews
• kCMFormatDescriptionExtension_HasLeftStereoEyeView
• kCMFormatDescriptionExtension_HasRightStereoEyeView
• kCMFormatDescriptionExtension_HeroEye
• kCMFormatDescriptionExtension_HorizontalDisparityAdjustment
• kCMFormatDescriptionExtension_LogTransferFunction
• kCMFormatDescriptionExtension_StereoCameraBaseline
• kCMFormatDescriptionHeroEye_Left
• kCMFormatDescriptionHeroEye_Right

Format Types

• CMClosedCaptionFormatType
• CMMetadataFormatType
• Metadata Format Types
• CMSubtitleFormatType
• Subtitle Format Types
• CMTimeCodeFormatType
• Time Code Formats
• CMTextFormatType
• CMPixelFormatType
• Tagged Buffer Group Format Types

Data Types

• CMVideoDimensions
• CMAudioFormatDescriptionMask
• CMMediaType
• CMAudioCodecType
• CMVideoCodecType
• CMTextDisplayFlags
• CMTextJustificationValue
• Media Type Constants
• Muxed Stream Types
• Audio Codec Types

Constants

• Audio Format Description Mask Codes
• Chroma Location Extension Constants
• Clean Aperture Extension Constants
• Closed Caption Format Type Constants
• Color Primary Extension Constants
• Field Detail Extension Constants
• Format Description Bridge Error Codes
• Format Description Constants
• Format Description Error Codes
• HEVC Temporal Level Info Constants
• Metadata Format Description Constants
• MPEG-2-conformant Formats
• Pixel Aspect Ratio Extension Constants
• Text Display Flags
• Text Format Constants
• Text Format Description Constants
• Text Justification Constants
• Time Code Flags
• Time Code Format Description Constants
• Transfer Function Extension Constants
• Video Codec Constants
• Video Pixel Formats
• Video Profile Constants
• YCbCrMatrix Extension Constants

See Also

Sample Processing

• CMSampleBuffer
• CMBlockBuffer
• CMTaggedBufferGroup
• CMAttachment
• CMTaggedBuffer
• CMMutableDataBlockBuffer
• CMReadOnlyDataBlockBuffer
• CMReadySampleBuffer
• CMSampleDataReference
• CMTaggedDynamicBuffer