<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HEAD><META http-equiv=Content-Type content="text/html; charset=iso-8859-1"></HEAD> <BODY bgColor=#ffffff><FONT face="verdana,arial" size="2"> Hi there,</P> one step in the encoding process (if I got it right), would becomputing a "floor curve" (according to the psychoacoustic model)<BR>and then subtracting this curve is from the MDCT data.</P> It's said that this works like a "whitening filter".</P> Could somebody please explain, how this is meant ?</P> I know, that a whitening filter removes the non-whitecomponents from a noise signal. But how can this be adopted<BR>to MDCT data ?</P> Is it like subtracting only the amplitude values, or some kind offrequency filtering as well ?</P> </P> Thanks,</P> Stoffke</P></FONT></BODY> --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.
On Tuesday, November 26, 2002, at 09:52 pm, Stoffke wrote:> I know, that a whitening filter removes the non-white > components from a noise signal. But how can this be adopted > to MDCT data ?I'm not sure I understand your confusion. MDCT data is in the frequency domain, in which 'white' [noise] means a flat frequency spectrum. The floor curve is subtracted in frequency space leaving a more evenly distributed spectrum, which is encoded separately from the floor. Hope that helps, -r <p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project homepage: http://www.xiph.org/ogg/ To unsubscribe from this list, send a message to 'vorbis-dev-request@xiph.org' containing only the word 'unsubscribe' in the body. No subject is needed. Unsubscribe messages sent to the list will be ignored/filtered.