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Example 5: Origin audience routing - AWS Elemental MediaTailor
ScenarioConfigurationFunction mappingWhat happens when the function runs

Example 5: Origin audience routing

Scenario

A broadcaster serves a linear channel from a channel assembly origin that uses program rules to deliver alternate content to different audiences. Viewers in certain postal codes must receive a regional blackout feed. The player sends the viewer's postal code as a zip query parameter. The broadcaster wants MediaTailor to translate it into the origin's aws.mediatailor.channel.audienceId query parameter on every manifest request, without exposing the audience logic to the player.

Configuration

Map postal code to audience (CUSTOM_OUTPUT):

{
    "FunctionId": "zipAudienceRouting",
    "FunctionType": "CUSTOM_OUTPUT",
    "CustomOutputConfiguration": {
        "Runtime": "JSONATA",
        "Output": {
            "manifest.aws.mediatailor.channel.audienceId": "{% player_params.zip in ['02101', '02102', '02108', '02110'] ? 'blackout' : 'allowed' %}"
        }
    }
}

The output key uses the manifest. namespace, so MediaTailor removes the prefix and appends the remainder, aws.mediatailor.channel.audienceId, as a query parameter on requests to the origin. The audience identifiers blackout and allowed must match the audiences defined in the channel's program rules. For more information, see Defining audience cohorts and alternate content with Program Rules.

Function mapping

{
    "FunctionMapping": {
        "PRE_SESSION_INITIALIZATION": "zipAudienceRouting"
    }
}

What happens when the function runs

  1. A viewer starts a playback session with ?zip=02101 on the session initialization request.

  2. MediaTailor runs the PRE_SESSION_INITIALIZATION lifecycle hook and runs zipAudienceRouting. The function reads player_params.zip, finds it in the blackout list, and writes blackout to manifest.aws.mediatailor.channel.audienceId.

  3. MediaTailor stores the value as a manifest query parameter on the session. Every request that MediaTailor makes to the origin for this session includes ?aws.mediatailor.channel.audienceId=blackout, and the origin returns the blackout feed.

  4. A viewer whose postal code is not in the list receives audienceId=allowed and the regular feed. A viewer who sends no zip parameter also receives allowed, because player_params.zip is undefined and the in test evaluates to false.

Tip

If the player also sends manifest.aws.mediatailor.channel.audienceId as a query parameter, the function's value takes precedence, so viewers cannot select their own audience by editing the URL.

For more information, see Custom output, Pre-session initialization, and MediaTailor manifest query parameters.