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# Sound sample description version 0 ('stsd')

A sound sample description that supports only uncompressed audio in raw or twos-complement format.

## Overview

There are currently three versions of the sound sample description, versions 0, 1 and 2. Version 0 supports only uncompressed audio in raw (`'raw '`) or twos-complement (`'twos'`) format, although these are sometimes incorrectly specified as either `'NONE'` or `0x00000000`.

Version 0 of the sound description format assumes uncompressed audio in `'raw '` or `'twos'` format, 1 or 2 channels, 8 or 16 bits per sample, and a compression ID of `0`.

## Topics

### Data fields

[`Sample description size`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Sample_description_size)

A 32-bit integer indicating the number of bytes in the sample description.

[`Data format`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Data_format)

A 32-bit integer indicating the format of the stored data.

[`Reserved`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Reserved)

Six bytes.

[`Data reference index`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Data_reference_index)

A 16-bit integer that contains the index of the data reference to use to retrieve data associated with samples that use this sample description.

[`Version`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Version)

A 16-bit integer that holds the sample description version.

[`Revision level`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Revision_level)

A 16-bit integer.

[`Vendor`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Vendor)

A 32-bit integer.

[`Number of channels`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Number_of_channels)

A 16-bit integer that indicates the number of sound channels used by the sound sample.

[`Sample size`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Sample_size)

A 16-bit integer that specifies the number of bits in each uncompressed sound sample.

[`Compression ID`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Compression_ID)

A 16-bit integer.

[`Packet size`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Packet_size)

A 16-bit integer.

[`Sample rate`](/documentation/quicktime-file-format/Sound_sample_description_version_0/Sample_rate)

A 32-bit unsigned fixed-point number (16.16) that indicates the rate at which the sound samples were obtained.


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