7. A method of generating an inverted index for a collection of multimedia documents, the method comprising: generating a positional representation of each multimedia document, at least one entry of the positional representation including a unique annotation and at least one occurrence position within its corresponding multimedia document, wherein times within a video clip of the corresponding multimedia document are derivable from the occurrence position; determining for each unique annotation among the generated positional representations, the positional representations that contain the annotation; and creating an entry in the inverted index for each unique annotation among the generated positional representations including the annotation and document identifiers of the multimedia documents of the positional representations that contain the annotation, wherein the method is executed by a processor.
7. A method of generating an inverted index for a collection of multimedia documents, the method comprising: generating a positional representation of each multimedia document, at least one entry of the positional representation including a unique annotation and at least one occurrence position within its corresponding multimedia document, wherein times within a video clip of the corresponding multimedia document are derivable from the occurrence position; determining for each unique annotation among the generated positional representations, the positional representations that contain the annotation; and creating an entry in the inverted index for each unique annotation among the generated positional representations including the annotation and document identifiers of the multimedia documents of the positional representations that contain the annotation, wherein the method is executed by a processor. 12. The method of claim 7 , further comprising adding third entries to each of the positional representations, each third entry including a unique term of always visible text and occurrence positions of the unique term in its corresponding multimedia document.