Identification of changed broadcast media items

摘要

Small changes in a broadcast version of a base media item can be identified by performing a multi-level comparison of digital fingerprints. A fingerprint of a base media item is compared to a fingerprint of a media broadcast to determine whether a media item embedded in a broadcast is likely, to a first level of certainty, to be the base media item. A second, more stringent, match between the fingerprint of the base media item and loosely matched items can be used to identify potentially-altered versions of the base media item. Potentially-altered versions can be compared against each other, and resulting matches are flagged as altered base media items, which can be fingerprinted and tested against broadcast fingerprints in the same manner as the base media item.

主权项

1. A method comprising:
obtaining a substantially-continuous fingerprint representing content broadcast by a media station, by executing a program instruction in a processor of a computing device; obtaining a first fingerprint representing a base version of a discrete media item, by executing a program instruction in a processor of a computing device; performing a first comparison attempting to match, to a first degree of certainty, portions of the substantially-continuous fingerprint to the first fingerprint, by executing a program instruction in a processor of a computing device; identifying portions of the substantially-continuous fingerprint that match the first fingerprint to the first degree of certainty as loose matches, by executing a program instruction in a processor of a computing device; for each of the loose matches:
performing a second comparison attempting to match, to a second degree of certainty more stringent than the first degree of certainty, the loose matches to the first fingerprint, by executing a program instruction in a processor of a computing device;identifying loose matches that fail to match the first fingerprint to the second degree of certainty as potentially-altered matches, by executing a program instruction in a processor of a computing device; attempting to match individual potentially-altered matches against other potentially-altered matches to the second degree of certainty, by executing a program instruction in a processor of a computing device; and generating a flagged match in response to one or more of the individual potentially-altered matches matching another one or more of the other potentially-altered matches to the second degree of certainty, by executing a program instruction in a processor of a computing device.