---
title: "Format atom ('frma')"
framework: quicktime-file-format
role: symbol
role_heading: Atom
path: quicktime-file-format/format_atom
---

# Format atom ('frma')

An atom that shows the data format of the stored sound media.

## Mentioned in

Sound sample data

## Topics

### Data fields

- [Size](quicktime-file-format/format_atom/size.md)
- [Type](quicktime-file-format/format_atom/type.md)
- [Data format](quicktime-file-format/format_atom/data_format.md)

## See Also

### Extending sound sample descriptions

- [siSlopeAndIntercept atom](quicktime-file-format/sislopeandintercept_atom.md)
- [siDecompressionParam atom ('wave')](quicktime-file-format/sidecompressionparam_atom.md)
- [Terminator atom ('0x00000000')](quicktime-file-format/terminator_atom.md)
- [MPEG-4 elementary stream descriptor atom  ('esds')](quicktime-file-format/mpeg-4_elementary_sound_stream_descriptor_atom.md)
- [Audio channel layout atom ('chan')](quicktime-file-format/audio_channel_layout_atom.md)
- [Subtitle follows track reference atom ('folw')](quicktime-file-format/subtitle_follows_track_reference_atom.md)