# Trick-play track via I-frames


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

## How the method works


When you create the HLS output group, you create one or more video outputs, in the usual way. For a reminder of the output group structure, look at the diagrams in [Organize encodes in an HLS output group](design-hls-package.md). In the output group, you enable the field to create an I-frame-only manifest that conforms to the HLS specification. 

MediaLive produces two child manifests for each encode—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


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

**Note**  
The information in this section assumes that you are familiar with the general steps for [creating a channel](creating-channel-scratch.md).

**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 **Manifest and segments**, for **I-frame only playlists**, choose **ENABLED**.

1. Set up the remaining fields in the output group [as you normally would](creating-hls-output-group.md). Set up the video, audio, and captions outputs and encodes [as you normally would](creating-a-channel-step6.md).