An apparatus for mapping versions of an audiovisual product comprising: a processing engine configured to perform a process to: identify an audio fingerprint associated with a temporal location within a first version of an audiovisual product; search for an audio fingerprint associated with a temporal location within a second version of the audiovisual product, which matches the audio fingerprint associated with the temporal location within the first version, to identify a first matching pair of audio fingerprints in the first version and the second version of the audiovisual product; if a first matching pair of audio fingerprints is found, determine whether a region comprising the temporal location associated with the audio fingerprint within the first version matches a corresponding region comprising the temporal location associated with the audio fingerprint within the second version by comparing the versions progressively away from the respective temporal locations to identify at least one further matching pair of audio fingerprints and thereby identify a matching region comprising the first matching pair of audio fingerprints and the at least one further matching pair of audio fingerprints in the first version and the second version of the audiovisual product; and if a matching region is found, store in a map representing at least one of the first and second versions, an indication of the temporal location of the matching region; and repeat the process by identifying further first matching pairs of audio fingerprints associated with temporal locations outside of any matching region(s), identifying further matching regions based on said further first matching pairs of audio fingerprints, and updating the map with indications of the temporal locations of the further matching regions. a processing engine configured to perform a process to: identify an audio fingerprint associated with a temporal location within a first version of an audiovisual product; search for an audio fingerprint associated with a temporal location within a second version of the audiovisual product, which matches the audio fingerprint associated with the temporal location within the first version, to identify a first matching pair of audio fingerprints in the first version and the second version of the audiovisual product; if a first matching pair of audio fingerprints is found, determine whether a region comprising the temporal location associated with the audio fingerprint within the first version matches a corresponding region comprising the temporal location associated with the audio fingerprint within the second version by comparing the versions progressively away from the respective temporal locations to identify at least one further matching pair of audio fingerprints and thereby identify a matching region comprising the first matching pair of audio fingerprints and the at least one further matching pair of audio fingerprints in the first version and the second version of the audiovisual product; and if a matching region is found, store in a map representing at least one of the first and second versions, an indication of the temporal location of the matching region; and repeat the process by identifying further first matching pairs of audio fingerprints associated with temporal locations outside of any matching region(s), identifying further matching regions based on said further first matching pairs of audio fingerprints, and updating the map with indications of the temporal locations of the further matching regions.