Re: Confusion about linear prediction within flac
"Timothy B. Terriberry" <[email protected]> Sun, 9 Sep 2018 13:01:41 -0700
| Newsgroups | gmane.comp.audio.compression.flac.devel |
|---|---|
| Message-ID | <[email protected]> |
Robin Patrick Decker wrote: > I would really appriciate an explanation or information on a good > resource to learn more about how the prediction coefficients are solved > for. The Wikipedia page on this subject is not terrible: https://en.wikipedia.org/wiki/Linear_prediction The very high-level answer is that if want to choose your coefficients to minimize the mean squared error of the prediction, then you get a least-squares problem where the matrix you're inverting is just the auto-correlation matrix of your signal (the Yule-Walker equations). The discrete Fourier transform is just a computationally efficient means of computing the auto-correlation, at least if your order is sufficiently high. > Once the lpc coefficients have been solved, as far as I understand you > must also store part of original signal with length equal to the > prediction order since you need the previous samples to predict the > next sample of which only the residual is known. For the next values > the residual is used to retrieve the original value which is fed into > the predction model to further reconstruct the time series. Is this > correct? Yes. _______________________________________________ flac-dev mailing list [email protected] http://lists.xiph.org/mailman/listinfo/flac-dev