---
title: "CMTimeCodeFormatDescriptionCopyAsBigEndianTimeCodeDescriptionBlockBuffer(allocator:timeCodeFormatDescription:flavor:blockBufferOut:)"
framework: coremedia
role: symbol
role_heading: Function
path: "coremedia/cmtimecodeformatdescriptioncopyasbigendiantimecodedescriptionblockbuffer(allocator:timecodeformatdescription:flavor:blockbufferout:)"
---

# CMTimeCodeFormatDescriptionCopyAsBigEndianTimeCodeDescriptionBlockBuffer(allocator:timeCodeFormatDescription:flavor:blockBufferOut:)

Copies the contents of a time code format description to a buffer in big-endian byte order.

## Declaration

```swift
func CMTimeCodeFormatDescriptionCopyAsBigEndianTimeCodeDescriptionBlockBuffer(allocator: CFAllocator?, timeCodeFormatDescription: CMTimeCodeFormatDescription, flavor: CMTimeCodeDescriptionFlavor?, blockBufferOut: UnsafeMutablePointer<CMBlockBuffer?>) -> OSStatus
```

## Parameters

- `allocator`: Allocator to use for allocating the CMBlockBuffer object. May be NULL.
- `timeCodeFormatDescription`: CMTimeCodeFormatDescription to be copied.
- `flavor`: Reserved for future use. Pass NULL for QuickTime Movie or ISO flavor.
- `blockBufferOut`: Receives new CMBlockBuffer containing TimeCodeDescription data structure in big-endian byte ordering.

## Discussion

Discussion On return, the caller owns the returned CMBlockBuffer, and must release it when done with it. note: The dataRefIndex field of the SampleDescription is intentionally filled with garbage values (0xFFFF).  The caller must overwrite these values with a valid dataRefIndex if writing the SampleDescription to a QuickTime/ISO file.

## See Also

### Working with Time Code Descriptions

- [CMTimeCodeDescriptionFlavor](coremedia/cmtimecodedescriptionflavor.md)
- [CMTimeCodeFormatDescriptionCreate(allocator:timeCodeFormatType:frameDuration:frameQuanta:flags:extensions:formatDescriptionOut:)](coremedia/cmtimecodeformatdescriptioncreate(allocator:timecodeformattype:frameduration:framequanta:flags:extensions:formatdescriptionout:).md)
- [CMTimeCodeFormatDescriptionGetFrameDuration(_:)](coremedia/cmtimecodeformatdescriptiongetframeduration(_:).md)
- [CMTimeCodeFormatDescriptionGetFrameQuanta(_:)](coremedia/cmtimecodeformatdescriptiongetframequanta(_:).md)
- [CMTimeCodeFormatDescriptionGetTimeCodeFlags(_:)](coremedia/cmtimecodeformatdescriptiongettimecodeflags(_:).md)
- [CMTimeCodeFormatDescriptionCreateFromBigEndianTimeCodeDescriptionBlockBuffer(allocator:bigEndianTimeCodeDescriptionBlockBuffer:flavor:formatDescriptionOut:)](coremedia/cmtimecodeformatdescriptioncreatefrombigendiantimecodedescriptionblockbuffer(allocator:bigendiantimecodedescriptionblockbuffer:flavor:formatdescriptionout:).md)
- [CMTimeCodeFormatDescriptionCreateFromBigEndianTimeCodeDescriptionData(allocator:bigEndianTimeCodeDescriptionData:size:flavor:formatDescriptionOut:)](coremedia/cmtimecodeformatdescriptioncreatefrombigendiantimecodedescriptiondata(allocator:bigendiantimecodedescriptiondata:size:flavor:formatdescriptionout:).md)
- [CMSwapBigEndianTimeCodeDescriptionToHost(_:_:)](coremedia/cmswapbigendiantimecodedescriptiontohost(_:_:).md)
- [CMSwapHostEndianTimeCodeDescriptionToBig(_:_:)](coremedia/cmswaphostendiantimecodedescriptiontobig(_:_:).md)