1. A video signal processing apparatus for processing a video signal, comprising: a metadata notation format identification block for identifying a notation format of metadata written in a predetermined language; a conversion table selection block for selecting a conversion table corresponding to said identified notation format of said metadata from among one or more conversion tables prepared in advance; a metadata notation format conversion block for converting said notation format of said metadata into a notation format compatible with said video signal processing apparatus on the basis of said selected conversion table; and a processing control block for controlling processing associated with said video signal on the basis of said metadata whose notation format has been converted, wherein the conversion table includes predetermined conversion information to convert a tag in the notation format in the predetermined language into a tag in the notation format compatible with the video signal processing apparatus, and wherein when the conversion table has no corresponding definition for the tag in the notation format in the predetermined language, a conversion of the tag in the notation format in the predetermined language generates a converted tag that includes a prefix representing the predetermined language and a name space of the tag.