1. A method to identify at least one content within a data stream, said content being needed by a given application executed on a test device, said method comprising the steps of: capturing at least one data stream; analyzing and filtering the data stream by: isolating at least one test stream of the data stream, disabling other sub-streams, and applying the test stream to the application so as to produce an output; applying the output to a comparator, said comparator receiving a reference and determining a distance between the application output and the reference, wherein: when the distance is below a predefined level, the isolating, disabling and applying steps are repeated with a new test stream selected among the previous test stream, the new test stream being a subset of the previous test stream, when the distance is above or equal to a second predefined level, the isolating, disabling and applying steps are repeated by selecting a different test stream from the data stream not already applied to the application.