Process for identifying audio content

A method of generating a fingerprint for identifying an audio signal, said method comprising the acts of:

• selecting a set of frequency subbands of said audio signal, with each frequency having a selected frequency range;
• for each subband, generating subband energy signal having a magnitude, in decibels (dB), equal to signal energy in the subband;
• forming an energy flux signal for each subband having a magnitude equal to the difference between subband energy signals of neighboring frames;
• determining the magnitude of frequency components bins of the energy flux signal for each subband;
• and
• forming a fingerprint comprising the magnitudes of the frequency component bins of the energy flux signal for all subbands.

A method of identifying a digital audio signal by monitoring the content of the audio signal, said method comprising the acts of:

• dividing a segment of the signal into overlapping frames;
• for each frame, determining the magnitude of frequency bins at different of frequencies;
• selecting a set of frequency subbands of a desired frequency range;
• for each subband and each frame, summing the frequency bins of the frame located within the subband to form a subband energy signal having a magnitude expressed in decibels (dB) for the given frame;
• forming an energy flux signal for each subband having a magnitude equal to the difference between subband energy signals of neighboring frames;
• determining the magnitude of frequency components bins of the energy flux signal for each subband;
• forming a fingerprint comprising the magnitudes of the frequency component bins of the energy flux signal for all subbands;
• comparing the fingerprint for the audio file to fingerprints in a database to identify the audio file.

A computer program product comprising:

• a computer readable storage medium having computer program code embodied therein for forming a fingerprint for identifying an audio file, said computer program code comprising:
• program code for causing a computing system to select a set of frequency subbands of said audio signal, with each frequency having a selected frequency range;
• for each subband, program code for causing a computing system to generate subband energy signal having a magnitude, in decibels (dB), equal to signal energy in the subband;
• program code for causing a computing system to form an energy flux signal for each subband having a magnitude equal to the difference between subband energy signals of adjacent frames;
• program code for causing a computing system to determine the magnitude of frequency components bins of the energy flux signal for each subband;
• and
• program code for causing a computing system to form a fingerprint comprising the magnitudes of the frequency component bins of the energy flux signal for all subbands.