Patent attributes
The present invention recognizes media content using signatures generated by network devices with limited processing power. An audio signal is prepared for application of a discrete Fourier transform (DFT). Outputs from the DFT include real components and imaginary components that are used to calculate output magnitudes associated with frequency bins. The frequency-amplitude pairs include the output magnitudes and the associated frequency bins. A signature of the audio signal is generated by selecting a predetermined number of frequency-amplitude pairs having dominant output magnitudes. The network devices that generate the signatures may transmit the signatures to a server for analysis. The server may trigger actions in response to detecting known content based on the received signatures matching known signatures.
