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  "title" : "Sound media information header atom ('smhd')"
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# Sound media information header atom ('smhd')

An atom that stores the sound media’s control information, such as balance.

## Overview

The layout of a sound media information header atom is as follows.

|Sound media information header atom                                                                      |Bytes|
|---------------------------------------------------------------------------------------------------------|-----|
|``doc://com.apple.qtff/documentation/quicktime-file-format/Sound_media_information_header_atom/Size``    |4    |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Sound_media_information_header_atom/Type``    |4    |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Sound_media_information_header_atom/Version`` |1    |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Sound_media_information_header_atom/Flags``   |3    |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Sound_media_information_header_atom/Balance`` |2    |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Sound_media_information_header_atom/Reserved``|2    |

## Topics

### Data fields

[`Size`](/documentation/quicktime-file-format/Sound_media_information_header_atom/Size)

A 32-bit integer that specifies the number of bytes in this sound media information header atom.

[`Type`](/documentation/quicktime-file-format/Sound_media_information_header_atom/Type)

A 32-bit integer that identifies the atom type.

[`Version`](/documentation/quicktime-file-format/Sound_media_information_header_atom/Version)

A 1-byte specification of the version of this sound media information header atom.

[`Flags`](/documentation/quicktime-file-format/Sound_media_information_header_atom/Flags)

A 3-byte space for sound media information flags.

[`Balance`](/documentation/quicktime-file-format/Sound_media_information_header_atom/Balance)

A 16-bit integer that specifies the sound balance of this sound media.

[`Reserved`](/documentation/quicktime-file-format/Sound_media_information_header_atom/Reserved)

Reserved for use by Apple.


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