# Filter a Track

You can filter a track to extract records that match particular conditions. For example, you can:

- extract records from OCR analysis results that match or contain a specified string
- extract records from a speech-to-text task that match or contain a specified string
- extract records from a face detection task that describe faces that appear in a particular region of the frame
- extract records from an object recognition task that match a specific object

To filter a track

1. Create a new configuration to send to Media Server with the `process` action, or open an existing configuration that you want to modify.

2. In the `[Session]` section, add a new task by setting the `EngineN` parameter. You can give the task any name, for example:

       [Session]
       Engine0=Ingest
       ...
       Engine5=Weather

3. Create a new configuration section to contain the task settings, and set the following parameters:

   `Type` | The ESP engine to use. Set this parameter to `filter`.
   `Input` | The output track, produced by another Media Server task, that you want to filter.

4. Set one of the following parameters to specify how the input track is filtered:

   `RequiredString` | A string that a record must match to be included in the output track. (The input track must contain text data).
   `RequiredSubString` | A string that a record must contain to be included in the output track. (The input track must contain text data).
   `LuaScript` | The name of a Lua script that defines conditions that a record must meet in order to be included in the output track from the ESP engine. For more information, see Write a Lua Script for an ESP Engine.

5. Save and close the configuration file. Micro Focus recommends that you save your configuration files in the location specified by the `ConfigDirectory` parameter.

Example

The following configuration produces a new track called `Weather.Output`. This track only contains records that include the word "weather".

    [Weather]
    Type=filter
    Input=speechtotext.result
    RequiredSubString=weather

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