[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

"Phase-Preserving Narrowed Autocorrelation"?


In "Computational auditory pathways to music understanding" (1997), Barry
Vercoe proposes the use of the Phase-Preserving Narrowed Autocorrelation
(PPNAC) for detecting recurring patterns and estimating tempo in a
representation of the loudness of audio data (1 value each 10 ms it
However there's no indication on what that is exactly, how it is computed
and where the "phase-preserving" feature resides in. Another feature of
the PPNAC seems to be to let large time scale phenomena influence smaller
time scales (e.g. a quarter-note pulse would induce a weaker response at
eighth-note, triplet-eighths, sixteenths, etc.). I didn't find details on
that either.
Would somebody have an idea of where to look for more detailed
information? Or maybe a hint to understand? Would there be some CSound
code around?

Fabien Gouyon
Music Technology Group IUA-UPF Barcelona
tel : (00 34) 93 542 28 64