Signature retrieval and matching for media monitoring

A media monitoring system comprising:

• a processor;
• and
• at least one memory storing instructions that, when executed by the processor, cause the media monitoring system to perform operations comprising:
• obtaining, from a first table, first qualifier data descriptive of a first reference signature, wherein the first reference signature is associated with a first site signature obtained from a monitored site, and wherein the first qualifier data comprises an offset that specifies a position of the first reference signature in a first block of reference signatures obtained from a second table different from the first table;
• aligning a first block of site signatures with a portion of the first block, a second block, and a third block of reference signatures based on the offset;
• comparing the first block of site signatures with the portion of the first block, the second block, and the third block of reference signatures;
• and
• crediting media, monitored at the monitored site, as corresponding to reference media represented by the first reference signature when the first block of site signatures matches with the portion of the first block, the second block, and the third block of reference signatures.

A non-transitory machine readable storage medium comprising instructions that, when executed, cause a processor to perform operations comprising:

• obtaining, from a first table, first qualifier data descriptive of a first reference signature, wherein the first reference signature is associated with a first site signature obtained from a monitored site, and wherein the first qualifier data comprises an offset that specifies a position of the first reference signature in a first block of reference signatures obtained from a second table different from the first table;
• aligning a first block of site signatures with a portion of the first block, a second block, and a third block of reference signatures based on the offset;
• comparing the first block of site signatures with the portion of the first block, the second block, and the third block of reference signatures;
• and
• crediting media, monitored at the monitored site, as corresponding to reference media represented by the first reference signature when the first block of site signatures matches with the portion of the first block, the second block, and the third block of reference signatures.