Audio signature extraction and correlation
First Claim
1. A method of correlating a test audio signal derived from a receiver to a reference audio signal, the method comprising:
- converting a first block of the test audio signal to a corresponding first frequency spectrum;
selecting segments between first frequency components of the first frequency spectrum as first test segments, the first test segments having first test slopes;
comparing, using a processor, signs of the first test slopes to signs of first reference slopes of first reference segments derived from the reference audio signal;
selecting segments between second frequency components of a second frequency spectrum as second test segments having corresponding second test slopes;
comparing, using the processor, signs of the second test slopes to signs of second reference slopes of second reference segments derived from the reference audio signal; and
determining a match between the test audio signal and the reference audio signal when at least a threshold ratio of the first test segments match the first reference segments and at least a threshold ratio of the second test segments match the second reference segments.
5 Assignments
0 Petitions
Accused Products
Abstract
A signature is extracted from the audio of a program received by a tunable receiver such that the signature characterizes the program. In order to extract the signature, blocks of the audio are converted to corresponding spectral moments. At least one of the spectral moments is then converted to the signature. Also, a test audio signal from a receiver is correlated to a reference audio signal by converting the test audio signal and the reference audio signal to corresponding test and reference spectra, determining test slopes corresponding to coefficients of the test spectrum and reference slopes corresponding to coefficients of the reference spectrum, and comparing the test slopes to the reference slopes in order to determine a match between the test audio signal and the reference audio signal.
85 Citations
22 Claims
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1. A method of correlating a test audio signal derived from a receiver to a reference audio signal, the method comprising:
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converting a first block of the test audio signal to a corresponding first frequency spectrum; selecting segments between first frequency components of the first frequency spectrum as first test segments, the first test segments having first test slopes; comparing, using a processor, signs of the first test slopes to signs of first reference slopes of first reference segments derived from the reference audio signal; selecting segments between second frequency components of a second frequency spectrum as second test segments having corresponding second test slopes; comparing, using the processor, signs of the second test slopes to signs of second reference slopes of second reference segments derived from the reference audio signal; and determining a match between the test audio signal and the reference audio signal when at least a threshold ratio of the first test segments match the first reference segments and at least a threshold ratio of the second test segments match the second reference segments. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of correlating a test audio signal derived from a receiver to a reference audio signal, the method comprising:
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converting a first block of the test audio signal to generate a first test spectrum; determining first test slopes corresponding to coefficients of the first test spectrum; converting the reference audio signal to first and second blocks of a reference spectrum; determining first reference slopes corresponding to first coefficients of the first block of the reference spectrum; determining second reference slopes corresponding to second coefficients of the second block of the reference spectrum; comparing, using a processor, signs of the first test slopes to signs of the first reference slopes in order to determine a match between the first block of the test spectrum and the first block of the reference spectrum; converting a second block of the test audio signal to generate a second test spectrum; determining second test slopes corresponding to coefficients of the second test spectrum; comparing, using a processor, signs of the second test slopes to signs of the reference slopes in order to determine a match between the second test spectrum and the reference spectrum; and determining that the test audio signal matches the reference audio signal when at least the first block of the test spectrum matches the first block of the reference spectrum and the second block of the test spectrum matches the second block of the reference spectrum. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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Specification