Function

CMAudioFormatDescriptionGetMagicCookie

Returns a read-only pointer to (and size of) the magic cookie inside an audio CMFormatDescription.

Declaration

const void * CMAudioFormatDescriptionGetMagicCookie(CMAudioFormatDescriptionRef desc, size_t *sizeOut);

Parameters

desc

CMFormatDescription being interrogated.

cookieSizeOut

Pointer to variable that will be written with the size of the cookie. Can be NULL.

Return Value

A read-only pointer to the magic cookie inside the audio format description.

Discussion

The magic cookie is a completely opaque piece of data, written and read only by the codec itself. A magic cookie is only present for codecs that require it; this API will return NULL if one does not exist. This API is specific to audio format descriptions, and will return NULL if called with a non-audio format description.

See Also

Audio-Specific Functions

CMAudioFormatDescriptionCreateSummary

Creates a summary audio format description from an array of audio format descriptions.

CMAudioFormatDescriptionCreate

Creates a format description for an audio media stream.

CMAudioFormatDescriptionEqual

Evaluates equality for the specified parts of two audio format descriptions.

CMAudioFormatDescriptionGetChannelLayout

Returns a read-only pointer to (and size of) the AudioChannelLayout inside an audio CMFormatDescription.

CMAudioFormatDescriptionGetFormatList

Returns a read-only pointer to (and size of) the array of AudioFormatListItem structs inside an audio CMFormatDescription.

CMAudioFormatDescriptionGetMostCompatibleFormat

Returns a read-only pointer to the appropriate AudioFormatListItem inside an audio CMFormatDescription.

CMAudioFormatDescriptionGetRichestDecodableFormat

Returns a read-only pointer to the appropriate AudioFormatListItem inside an audio CMFormatDescription.

CMAudioFormatDescriptionGetStreamBasicDescription

Returns a read-only pointer to the AudioStreamBasicDescription inside an audio CMFormatDescription.

CMDoesBigEndianSoundDescriptionRequireLegacyCBRSampleTableLayout

Examine a big-endian SoundDescription data structure in a CMBlockBuffer, and report whether the sample tables will need to use the legacy CBR layout.

CMSwapBigEndianSoundDescriptionToHost

Converts a SoundDescription data structure from big-endian to host-endian in place.

CMSwapHostEndianSoundDescriptionToBig

Converts a SoundDescription data structure from host-endian to big-endian in place.

CMAudioFormatDescriptionCreateFromBigEndianSoundDescriptionData

Creates a CMAudioFormatDescription from a big-endian SoundDescription data structure.

CMAudioFormatDescriptionCreateFromBigEndianSoundDescriptionBlockBuffer

Creates a CMAudioFormatDescription from a big-endian SoundDescription data structure in a CMBlockBuffer.

CMAudioFormatDescriptionCopyAsBigEndianSoundDescriptionBlockBuffer

Copies the contents of a CMAudioFormatDescription to a CMBlockBuffer in big-endian byte ordering.