# Trick-play track via I-frames
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In an HLS output group, you can support a trick-play track by providing an I-frame-only manifest.

## How the method works
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When you create the HLS output group, you create one or more video outputs, in the usual way. In each video output, you enable the field to create an I-frame-only manifest that conforms to the HLS specification. 

Elemental Live produces two child manifests for each encode (stream)—one manifest for handling the video in the usual way, and the I-frame-only manifest. The I-frame-only manifest lets the downstream player identify specific video frames to request, to construct the trick-play track. So this trick-play track method doesn't produce additional encodes in the output group. 

Each I-frame-only manifest contains the following:
+ One `#EXT-X-I-FRAMES-ONLY `tag, to indicate that the manifest is I-frame-only.
+ Many `#EXT-X-BYTERANGE `entries. Each entry identifies the position of an I-frame position.

## Setting up
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You set up the trick-play track once for the entire HLS output group.

**Note**  
The information in this section assumes that you are familiar with the general steps for creating an event.

**To set up an I-frame-only manifest**

Include these steps when you create the HLS output group. 

1. In the **HLS Output Group**, in **HLS Outputs**, choose **Add Output** to add an output. Or display an existing output.

1. In the output, choose **Advanced** to open that section, then select **Add I-frame Only Manifest**.

1. Set up the remaining fields in the output group as you normally would. Set up the video, audio, and captions outputs and encodes as you normally would.