---
title: Timecode sample description
framework: quicktime-file-format
role: symbol
role_heading: Atom
path: quicktime-file-format/timecode_sample_description
---

# Timecode sample description

An atom that defines how to interpret time code media data.

## Overview

Overview The timecode sample description contains information that defines how to interpret time code media data. This sample description is based on the standard sample description header, as described in Sample description atom ('stsd'). The data format field in the sample description is always set to 'tmcd'. The timecode media handler also adds some of its own fields to the sample description.

## Topics

### Data fields

- [Reserved](quicktime-file-format/timecode_sample_description/reserved.md)
- [Flags](quicktime-file-format/timecode_sample_description/flags.md)
- [Time scale](quicktime-file-format/timecode_sample_description/time_scale.md)
- [Frame duration](quicktime-file-format/timecode_sample_description/frame_duration.md)
- [Number of frames](quicktime-file-format/timecode_sample_description/number_of_frames.md)
- [Reserved](quicktime-file-format/timecode_sample_description/reserved2.md)
- [Source reference](quicktime-file-format/timecode_sample_description/source_reference.md)

## See Also

### Storing time code data

- [Timecode media information atom ('tcmi')](quicktime-file-format/timecode_media_information_atom.md)
- [Timecode sample data](quicktime-file-format/timecode_sample_data.md)
- [Creating a timecode track for 29.97 FPS video](quicktime-file-format/creating_a_timecode_track_for_2997_fps_video.md)