> For the complete documentation index, see [llms.txt](https://stage-precision.gitbook.io/grid/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://stage-precision.gitbook.io/grid/timeline/timeline-basics/timecode-and-timelines.md).

# Timecode & Timelines

Drive a Timeline from external Timecode, select and offset Timecode Providers, and use the Timeline Playhead as a Timecode source for internal or external systems.

<div align="left"><figure><img src="https://1761958297-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FDcGqBEYUYkl2mQzGbOue%2Fuploads%2Fmf7Xvh8CW29R7KPppkpA%2Fimage.png?alt=media&amp;token=1bbaf1cd-f785-4c15-8da5-4b825835c62b" alt="" width="360"><figcaption></figcaption></figure></div>

A Timeline can either run independently using its own playback controls or be driven by an **external Timecode Provider**.

Timelines can also generate Timecode from their own Playhead position, allowing a Timeline to act as a Timecode source for other internal or external systems.

***

## External Timecode

External Timecode can be used to control the current position of a Timeline.

When the Timeline is actively driven by external Timecode, the incoming Timecode determines the Playhead position.

### Arm Timecode

Enable **Arm Timecode** to allow the Timeline to listen to the selected external Timecode Provider.

Arming the Timeline does not itself define the Timecode source. The desired source is selected separately using **Timecode Provider**.

### Timecode Provider

**Timecode Provider** defines which Timecode source is used to drive the Timeline.

Some globally available Timecode Providers are available by default.

Additional sources such as:

* MTC
* LTC
* SDI Timecode

must first be created as Timecode Provider objects in the **Project Tree**.

Once created, they become available in the Timeline's **Timecode Provider** selection.

### Offset

The **Offset** setting applies a time offset to the incoming Timecode before it drives the Timeline.

This can be used to align the Timeline with a Timecode source that requires a timing offset.

### Driven by External TimeCode

**driven by external TimeCode** is a read-only status indicator.

It shows whether the Timeline is currently being actively driven by external Timecode.

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## Playback While Driven by External Timecode

When external Timecode is actively driving the Timeline, the external source controls the Playhead position.

Manual or Timeline-based changes to the Playhead cannot permanently override the incoming Timecode position.

For example:

* Moving the Playhead manually is overridden by the external Timecode.
* **Jump to Time** is overridden by the external Timecode.
* **Jump to Cue** is overridden by the external Timecode.
* A **Pause Cue** cannot hold the Timeline at its position while external Timecode continues to drive it.

These behaviors differ from normal Timeline playback, where the Timeline runs independently in free run.

***

## Output Timecode

A Timeline can also generate Timecode based on its current **Playhead position**.

The **Output Timecode** settings control this generated Timecode.

The resulting Timecode can be used as a **Timecode Provider** for:

* internal Grid Studio purposes
* external Timecode output

Detailed settings for Timecode generation, interpolation, drop behavior, and Timecode Providers are covered in the dedicated **Timecode** documentation.