A method for encapsulating media data, the method comprising: identifying, according to a parameter independent from the encapsulation, a portion of the media data or a set of items of information related to a portion of the media data, and encapsulating the portion of media data or the set of items of information as entities in a media file, the entities being grouped into a set of entities associated with a first indication representative of the parameter, wherein the media file comprises a second indication signalling to a client that the set of entities is to be parsed only if the client has knowledge about the first indication.