Martijn van Beurden wrote: > Hi, > > > If I understand this correctly, these new apodization functions only > > affect compression and that files compressed with these new functions > > will still decode correctly with older versions of the FLAC decoder. > > > > Is that right? > > Yes, that is correct. These functions are used to window the > audiodata, but only for the predictor stage. What these new > function enable, practically speaking, is using only part of the > signal to generate a predictor. My theory is that this helps > because short transients introduce noise into the predictor. The > predictor becomes very good at prediciting one part of the > signal, instead of mediocre for the whole block. > > For more information on the whole window-thing, it might be a > good idea to see this hydrogenaudio-post by Josh himself: > http://www.hydrogenaud.io/forums/index.php?showtopic=44229 > > One thing to note is that this patch only affects the encoder > stage that evaluates various possible predictors, not the actual > coding stage.
Great, thanks for the explanation. I committed this patch and then amended the commit message with some of the info from your email. > This patch only add the new windows to the codebase. My > follow-up e-mail (Retuning compression levels) suggests one > possible retuning of the compression levels 6, 7 and 8 that make > use of these new functions. I'll address that separately. Cheers, Erik -- ---------------------------------------------------------------------- Erik de Castro Lopo http://www.mega-nerd.com/ _______________________________________________ flac-dev mailing list [email protected] http://lists.xiph.org/mailman/listinfo/flac-dev
