The EMS only supports AAC audio and H.264 video for input. If you want to input MP3, you can use the EMS Transcoder to convert your audio to AAC before feeding it to EMS. The EMS API Definitions and the EMS User Guide documents have sections with details and examples for the Transcode API command.
Please refer to the EvoStream Web Services User Guide to check if the EMS Event Notification System, plus some custom PHP scripts of your own, can help you regarding Google Analytics. Several Web Service Plugins are provided free with source code in the Downloads section of the EvoStream website. You can use them for reference to develop your own plugins.