Contents

CMVideoFormatDescriptionGetExtensionKeysCommonWithImageBuffers()

Returns an array of keys that you use for video format description extensions, image buffer attachments, and attributes.

Declaration

func CMVideoFormatDescriptionGetExtensionKeysCommonWithImageBuffers() -> CFArray

Discussion

When specifying a CMFormatDescription for a CMSampleBuffer, the format description must be consistent with formatting information attached to the CVImageBuffer. The width, height, and codecType must match (for CVPixelBuffers the codec type is given by CVPixelBufferGetPixelFormatType(pixelBuffer); for other CVImageBuffers, the codecType must be 0). The format description extensions must match the image buffer attachments for all the keys in the list returned by this function (if absent in either they must be absent in both). Currently, the list is:

  • kCMFormatDescriptionExtension_CleanAperture

  • kCMFormatDescriptionExtension_FieldCount

  • kCMFormatDescriptionExtension_FieldDetail

  • kCMFormatDescriptionExtension_PixelAspectRatio

  • kCMFormatDescriptionExtension_ColorPrimaries

  • kCMFormatDescriptionExtension_TransferFunction

  • kCMFormatDescriptionExtension_GammaLevel

  • kCMFormatDescriptionExtension_YCbCrMatrix

  • kCMFormatDescriptionExtension_ICCProfile

  • kCMFormatDescriptionExtension_ChromaLocationTopField

  • kCMFormatDescriptionExtension_ChromaLocationBottomField

See Also

Working with Video Descriptions