---
title: "CMTextFormatDescriptionCopyAsBigEndianTextDescriptionBlockBuffer(allocator:textFormatDescription:flavor:blockBufferOut:)"
framework: coremedia
role: symbol
role_heading: Function
path: "coremedia/cmtextformatdescriptioncopyasbigendiantextdescriptionblockbuffer(allocator:textformatdescription:flavor:blockbufferout:)"
---

# CMTextFormatDescriptionCopyAsBigEndianTextDescriptionBlockBuffer(allocator:textFormatDescription:flavor:blockBufferOut:)

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

## Declaration

```swift
func CMTextFormatDescriptionCopyAsBigEndianTextDescriptionBlockBuffer(allocator: CFAllocator?, textFormatDescription: CMTextFormatDescription, flavor: CMTextDescriptionFlavor?, blockBufferOut: UnsafeMutablePointer<CMBlockBuffer?>) -> OSStatus
```

## Parameters

- `allocator`: Allocator to use for allocating the CMBlockBuffer object. May be NULL.
- `textFormatDescription`: CMTextFormatDescription to be copied.
- `flavor`: Reserved for future use. Pass NULL for QuickTime Movie or ISO flavor.
- `blockBufferOut`: Receives new CMBlockBuffer containing TextDescription 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 Text Descriptions

- [CMTextDescriptionFlavor](coremedia/cmtextdescriptionflavor.md)
- [CMTextFormatDescriptionGetDefaultStyle(_:localFontIDOut:boldOut:italicOut:underlineOut:fontSizeOut:colorComponentsOut:)](coremedia/cmtextformatdescriptiongetdefaultstyle(_:localfontidout:boldout:italicout:underlineout:fontsizeout:colorcomponentsout:).md)
- [CMTextFormatDescriptionGetDefaultTextBox(_:originIsAtTopLeft:heightOfTextTrack:defaultTextBoxOut:)](coremedia/cmtextformatdescriptiongetdefaulttextbox(_:originisattopleft:heightoftexttrack:defaulttextboxout:).md)
- [CMTextFormatDescriptionGetDisplayFlags(_:displayFlagsOut:)](coremedia/cmtextformatdescriptiongetdisplayflags(_:displayflagsout:).md)
- [CMTextFormatDescriptionGetFontName(_:localFontID:fontNameOut:)](coremedia/cmtextformatdescriptiongetfontname(_:localfontid:fontnameout:).md)
- [CMTextFormatDescriptionGetJustification(_:horizontalOut:verticalOut:)](coremedia/cmtextformatdescriptiongetjustification(_:horizontalout:verticalout:).md)
- [CMTextFormatDescriptionCreateFromBigEndianTextDescriptionBlockBuffer(allocator:bigEndianTextDescriptionBlockBuffer:flavor:mediaType:formatDescriptionOut:)](coremedia/cmtextformatdescriptioncreatefrombigendiantextdescriptionblockbuffer(allocator:bigendiantextdescriptionblockbuffer:flavor:mediatype:formatdescriptionout:).md)
- [CMTextFormatDescriptionCreateFromBigEndianTextDescriptionData(allocator:bigEndianTextDescriptionData:size:flavor:mediaType:formatDescriptionOut:)](coremedia/cmtextformatdescriptioncreatefrombigendiantextdescriptiondata(allocator:bigendiantextdescriptiondata:size:flavor:mediatype:formatdescriptionout:).md)
- [CMSwapBigEndianTextDescriptionToHost(_:_:)](coremedia/cmswapbigendiantextdescriptiontohost(_:_:).md)
- [CMSwapHostEndianTextDescriptionToBig(_:_:)](coremedia/cmswaphostendiantextdescriptiontobig(_:_:).md)