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I wonder if there’s some iterative algorithm that would work here. When synthesizing audio from the short-time Fourier transform (STFT) sometimes you have unkn
by ssfrr 5y ago
I wonder if there’s some iterative algorithm that would work here.
When synthesizing audio from the short-time Fourier transform (STFT) sometimes you have unknown or noisy phase, and there’s an algorithm called Griffey-Lim that’s pretty common for finding the corresponding time-domain signal. You start in the STFT-domain and continually swap between time and STFT domains, each time fixing the STFT magnitudes. Eventually the phase tends to converge (but not sure if that’s guaranteed).
Maybe there’s something similar here where you keep swapping back and forth while applying the blue spectrum and uniform sample histogram constraints (or partially applying them in a gradient-descent fashion).
(Side note that there are other/better phase estimation algos for this problem, but Griffin-Lim is simple and relatively common)
- nitrogen 5y agoCan you link to a paper, summary, or textbook with this algorithm? I'd like to learn more, but searching for "Griffey-Lim" only returns this HN thread, and a bunch of very unrelated news items about money laundering.
- raphlinus 5y agoPretty sure it's this paper: https://ieeexplore.ieee.org/document/1164317 https://ieeexplore.ieee.org/document/1164317 That is Griffin-Lim, which matches the second mention but not the first. It's a fairly well known algorithm for reconstructing speech from spectrum, though I believe is largely superseded these days by vocoders based on neural techniques. (Actually I just checked and the original Tacotron paper cites Griffin-Lim; I do think newer neural TTS approaches have gone beyond it, however)