Creating a custom Media Engine allows you to use new media software to perform Media Actions on files in ADAM, such as creating previews, extracting textual content or reading XMP metadata. The provider model in ADAM allows you to easily plug this custom provider in together with the built-in Media Engines.

Basic information about how to create a custom MediaEngine can be found in the Adam Developer Guide. If you are developing your first MediaEngine you should definitely take a look at our documentation.

The actual purpose of this blog post is to give a few hints and tricks when creating your own MediaEngine. Some frequently asked questions or things to make your coding process easier.

Return value

The return value of the Run method is a boolean. Remember the following rules:

• The requested media action was executed successfully: return true.
• The requested media action failed during the process: throw an exception.
• The requested media action is not supported in your MediaEngine: return false.

Switch Case

Use a Switch Case statement in the 'Run' method for processing each MediaAction. e.g.

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switch (action.Id)
{
  case CreatePreviewImagesMediaAction.ActionId:
    return RunCreatePreviewImagesAction((CreatePreviewImagesMediaAction)action);

  case ReadContentMediaAction.ActionId:
    return RunReadContentAction((ReadContentMediaAction)action);

  default:
    return false;
}

Disposing

A frequent mistake is to think that no private Fields can be used in your engine. It is important to know that the 'Run' method is executed repeatedly for every available MediaAction, but the 'Dispose' method is only executed once, after the engine is done processing.
That's why you can safely store some information in private fields and you do not need to reload or reassign values for each time 'Run' is executed.

MediaEngine Exception

When creating your engine a 'MediaEngineException' is available. You can throw this exception for an appropriate error that occured during processing.

Getting it done

When you When you are finished coding you only need to register and activate your custom provider into ADAM. Detailed information on how to do this can be found in the Adam Developer Guide.
After this your engine is ready to use. Remember that it is also possible to test it in the Adam MediaEngineTester utility. A blog post about how to use this utility can be found here.