Audio data fingerprint searching

1 . A method of matching a set of input fingerprint blocks, each fingerprint block representing at least a part of an information signal, with fingerprints stored in a database that identify respective information signals, the method comprising the steps of:

selecting a first fingerprint block of said input set of fingerprint blocks;

finding at least one fingerprint block in said database that matches the selected fingerprint block;

selecting a further fingerprint block from said set of fingerprint blocks at a predetermined position relative to said first selected fingerprint block;

locating at least one corresponding fingerprint block in said database at the predetermined position relative to said found fingerprint block; and

determining if said located fingerprint block matches said selected further fingerprint block.

2 . A method as claimed in claim 1 , the method further comprising iteratively repeating the steps of

selecting a further fingerprint block, locating a corresponding fingerprint block in said database and determining if said located fingerprint block matches said selected further fingerprint block for different predetermined positions relative to the first selected fingerprint block.

3 . A method as claimed in claim 1 , wherein said predetermined position is an adjacent position.

4 . A method as claimed in claim 1 , wherein a match in said finding step is deemed to have occurred if the number of differences between the fingerprint block is below a first threshold, and a match in said determining step is deemed to have occurred if the number of differences between the fingerprint blocks is below a second threshold.

5 . A method as claimed in claim 4 , wherein said second threshold is different from said first threshold.

6 . A method as claimed in claim 1 , further comprising the steps of: receiving an information signal;

dividing the information signal into sections; and

generating said input block by calculating a fingerprint block for each section.

7 . A method of generating a logging report for an information signal comprising the steps of:

dividing the information signal into similar content segments;

generating an input fingerprint block for each segment; and

repeating the method steps as claimed in claim 1 so as to identify each of said blocks.

8 . A method as claimed in claim 7 , wherein said information signal comprises an audio signal, and wherein each segment corresponds to at least a portion of a song.

9 . A computer program arranged to perform the method as claimed in claim 1 .

10 . A record carrier comprising a computer program as claimed in claim 9 .

11 . A method of making available for downloading a computer program as claimed in claim 9 .

12 . An apparatus arranged to match a set of input fingerprint blocks, each fingerprint block representing at least a part of an information signal, with fingerprints stored in a database that identify respective information signals, the apparatus comprising a processing unit arranged to:

select a first fingerprint block of said set of input fingerprint blocks;

find at least one fingerprint block in said database that matches the selected fingerprint block;

select a further fingerprint block from said set of input blocks at a predetermined position relative to said first selected fingerprint block;

locate at least one corresponding fingerprint block in said database at the predetermined position relative to said found fingerprint block; and

determine if said located fingerprint block matches said selected further fingerprint block.

13 . An apparatus as claimed in claim 12 , further comprising a database arranged to store fingerprints identifying respective information signals and meta-data associated with each signal.

14 . An apparatus as claimed in claim 12 , further comprising a receiver for receiving an information signal, and a fingerprint generator arranged to generate said set of input fingerprint blocks from said information signal.