Methods and apparatus to extract a pitch-independent timbre attribute from a media signal
Methods and apparatus to extract a pitch-independent timbre attribute from a media signal are disclosed. An example apparatus includes an audio characteristic extractor to determine a logarithmic spectrum of an audio signal; transform the logarithmic spectrum of the audio signal into a frequency domain to generate a transform output; determine a magnitude of the transform output; and determine a timbre attribute of the audio signal based on an inverse transform of the magnitude.
1 . A computing device comprising:
one or more processors; and
a tangible, non-transitory computer readable storage medium comprising instructions which, when executed cause the one or more processors to perform a set of operations comprising:
accessing a media signal;
extracting a pitch-independent timbre spectrum of the accessed media signal; and
classifying the accessed media signal based on data corresponding to the pitch-independent timbre spectrum.
2 . The computing device of claim 1 , wherein the media signal comprises an audio signal.
3 . The computing device of claim 1 , wherein the media signal comprises an audio component of a video signal.
4 . The computing device of claim 3 , wherein the set of operations further comprise extracting the media signal from the video signal.
5 . The computing device of claim 1 , wherein extracting a pitch-independent timbre of the accessed media signal comprises determining a logarithmic spectrum of the media signal and transforming the logarithmic spectrum of the media signal into a frequency domain to generate a transform output.
6 . The computing device of claim 5 , wherein determining the logarithmic spectrum of the media signal comprises using a constant Q transform.
7 . The computing device of claim 5 , wherein extracting a pitch-independent timbre of the accessed media signal comprises determining a magnitude of the transform output and a timbre attribute of the media signal based on an inverse transform of the magnitude.
8 . The computing device of claim 7 , wherein determining the transform of the logarithmic spectrum is based on a Fourier transform and determining the inverse transform is based on using an inverse Fourier transform.
9 . The computing device of claim 7 , wherein determining a timbre-independent pitch attribute of the media signal is based on an inverse transform of a complex argument of the transform of the logarithmic spectrum.
10 . The computing device of claim 1 , wherein the classification corresponds to at least one of an instrument or a genre.
11 . The computing device of claim 1 , wherein the set of operations further comprises identifying a media source of the media signal based on the classification.
12 . The computing device of claim 1 , wherein the set of operations further comprises comparing the pitch-independent timbre spectrum of the media signal to one or more reference pitch-independent timbre spectrums, and wherein classifying the media signal is based on matching one or more reference pitch-independent timbre spectrums to the extracted pitch-independent timbre spectrum.
13 . The computing device of claim 1 , the set of operations further comprises comparing the pitch-independent timbre spectrum of the media signal to one or more reference pitch-independent timbre spectrums, and based on determining that the extracted pitch-independent timbre spectrum does not match the one or more reference pitch-independent timbre spectrums, prompt for additional information corresponding to the media signal.
14 . The computing device of claim 1 , wherein the set of operations further comprises determining a device setting adjustment based on the classification.
15 . A tangible, non-transitory computer readable storage medium comprising instructions which, when executed cause one or more processors to perform a set of operations comprising:
accessing a media signal;
extracting a pitch-independent timbre spectrum of the accessed media signal; and
classifying the accessed media signal based on data corresponding to the pitch-independent timbre spectrum.
16 . The tangible, non-transitory computer readable storage medium of claim 15 , wherein the media signal comprises an audio signal.
17 . The tangible, non-transitory computer readable storage medium of claim 15 , wherein the media signal comprises an audio component of a video signal.
18 . The tangible, non-transitory computer readable storage medium of claim 17 , wherein the set of operations further comprises extracting the media signal from the video signal.
19 . The tangible, non-transitory computer readable storage medium of claim 15 , wherein extracting a pitch-independent timbre of the accessed media signal comprises determining a logarithmic spectrum of the media signal and transforming the logarithmic spectrum of the media signal into a frequency domain to generate a transform output.
20 . A computer-implemented method comprising:
accessing, by one or more processors, a media signal;
extracting, by the one or more processors, a pitch-independent timbre spectrum of the accessed media signal; and
classifying, by the one or more processors, the accessed media signal based on data corresponding to the pitch-independent timbre spectrum.