Data playback context
======================

The context handles incoming eye tracker data before to pass them to a processing pipeline.

## data_playback_context.json

For this use case we need to read Tobii Pro Glasses 2 records: **ArGaze** provides a [ready-made context](../../user_guide/eye_tracking_context/context_modules/tobii_pro_glasses_2.md) class to playback data from records made by this device.

While *segment* entry is specific to the [TobiiProGlasses2.SegmentPlayback](../../argaze.md/#argaze.utils.contexts.TobiiProGlasses2.SegmentPlayback) class, *name* and *pipeline* entries are part of the parent [ArContext](../../argaze.md/#argaze.ArFeatures.ArContext) class.

```json
{
	"argaze.utils.contexts.TobiiProGlasses2.SegmentPlayback": {
		"name": "Tobii Pro Glasses 2 segment playback",
		"segment": "/Volumes/projects/fbr6k3e/records/4rcbdzk/segments/1",
		"pipeline": "post_processing_pipeline.json"
	}
}
```

The [post_processing_pipeline.json](pipeline.md) file mentioned above is described in the next chapter.