similar to: Using the vorbis psychoacoustics model

(Disclaimer: this is not an LPC vs. LSP question) After looking at the Vorbis code I was wondering why you were using LSP to quantize the spectral envelope instead of simply quantizing the cepstrum (DCT(log(envelope))) or modified cepstrum (DCT(envelope.^alpha)). To me it seems like when the information is already in the frequency domain, there's no need to go back to LPC. Also, I think a DCT

Hi, I'd like to contribute to Vorbis and I think this may be of some interest for low bitrate coding. I have been experimenting with low bit-rate coding for the high-band (11 kHz to 22 kHz) and, though I haven't yet started quantizing my coefficients (a gain and an LPC filter), I expect to be able to approximate the whole 11-22 kHz band with around 1000 bits/s per channel (maybe even 500

Hi I have gone through the document available in the net regarding the Vorbis encoder /Decoder. Based on that i have prepared a understanding document on the encoder/decoder block. I would like to know whether my understanding of the coder is OK. If there are any other additional block /information pl. provide me with the same. Thanks and regards S.Padmashri <HR NOSHADE> <UL>

I saw from the interview on Slashdot that there is no support for channel coupling in Vorbis. I would like to help work on that. Has anything been started about that? I don't know yet whether if could work "in real life", but I have started to work on a way to do adaptative coupling between two channels (by finding the best transformation to predict one channel from the other). I

I have noticed may broken links in the vorbis documentation. For instances, none of the links in the "Vorbis analysis and synthesis" and "Vorbis coding and decoding" sections work. Where has that documentation been? Jean-Marc Valin -- Jean-Marc Valin Universite de Sherbrooke - Genie Electrique valj01@gel.usherb.ca --- >8 ---- List archives:

After playing with the vorbis code for a while and doing tons of hacks and analysis on it, I've found it to perform very poorly with impulse signals. The MDCT seems to cause lots of spreading, and it seems to result in much worse impulse performance then mp3. What is the current plan on handling this? Will a smart quantizer be able to avoid it? I've been looking at various ways of

I've been reading through the source, and I can't understand where compression is occuring! It appears that it should be ouputing all of the LSP and residule data, but the output is smaller then the input (it's about 500Kb/s+, but it bzip2's to about 320Kb/s). The output sounds okay, but has signifantly worse S/N then mp3 at 320. --- >8 ---- List archives:

xiphmont@xiph.org (Monty) writes: > Really, folks, several of you are debating the most fundamental of signal > processing concepts. Go get an undergraduate level book on signal > processing (eg, _Understanding Signal Processing_ or _Signals and Systems_) > and read it. This is all covered first month. On this subject, could you (all) recommend some good vorbis-relevant dsp and

Hello folks, An incredible amount of work got done in the past week and a half. And I missed the arbitrary, meaningless launch deadline. Not much new there... In the past week, developers contributed plugins for Winamp (thanks Jack and Michael), and kmpg (thanks Martin). Sonique added Vorbis support (thanks Andrew), although that won't appear in the 1.5 version just released; expect to

Hello folks, An incredible amount of work got done in the past week and a half. And I missed the arbitrary, meaningless launch deadline. Not much new there... In the past week, developers contributed plugins for Winamp (thanks Jack and Michael), and kmpg (thanks Martin). Sonique added Vorbis support (thanks Andrew), although that won't appear in the 1.5 version just released; expect to

Hi folks, I've been dickering around again, wasting the time away.... and today Brian Zisk (chief Vorbis Evangelist among other things) said, "Hey! We need to demo to the world on the 4th of April!" Hooo boy. Time to suck it up and bang it out. The Vorbis libs are not a problem. I'm in process of checking in my new psychoacoustics (they're real pretty!) based on

Hi, I have included the oggvorbis encoding and playback stuff in the Linux-Mandrake distro back in August 2000. At that time I put the "nightly CVS" version, which worked just fine. Then on Mon Nov 27 I noticed some RPM's labelled "1.0beta3" on the website so I upgraded with these ones. Since then we have had some serious problems in encoding: approx 20% of the WAV

Hello, I'd like to know there is any place (web, document...) where I can see which the vorbis' psychoacoustic model is, at least for the reference encoder (how it works, algorithms, filter banks, scalefactors, etc., or if it doesn't use any of this things at all...), or if the only way of looking at it is within the psy.c. I've been looking for it in the Vorbis' site and in

Hi folks, I'm doing a merge of my current branch onto the mainline (for testing) today. I believe it to be stable. Just a little more vorbisfile testing. After the merge, I have a few more patches to apply, then onto cascading/coupling. New stuff: Floor backend 1 and residue backend 1; both are present, but the mainline modes won't use either yet. Naturally, both are enabled for

Hello! I don`t know C or C++, but I want to prepare some psychocuostic experiments in the MatLab. Shuold you tell me where I can find detailed description of the Vorbis psychoacoustic model? <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'

During the interesting interview that binaryfreedom has made with Monty and Jack, Monty mentions cascading, a feature that will be added, quote: "Cascading is the ability to make multiple passes through the frequency spectrum, iteratively filling in more detail, like a progressive jpeg". What are the advantages of something like this - does this generally improves quality or is it used

Hi Guys, I want to compile libvorbis, but I get this error message if I made a make. I use Sun Solaris 9 on a UltraSPARC Server and gcc 3.3 can anyone help me, please? <p>Best Thanks Daniel Here the message output from compiling. ----------------------------------------- /usr/ccs/bin/ld -G -z defs -h libvorbis.so.0 -o .libs/libvorbis.so.0.3.0 mdct.lo smallft.lo block.lo envelope.lo

Is anybody interested in cleanly separating encode and decode in vorbis? I'm trying to take a stab at it myself from the head of cvs as of this morning, but it looks like a lot of files contain both encode-only and decode-only functions. An obvious one is mdct.c, which contains mdct_forward and mdct_backward (which isn't that big of a deal, since both are pretty well-contained, but it

ltconfig placeholder shoud be removed. Makefile.am : some stuff copied from branch_beta3 ogg lib must be added only where necesary. vq subdir Makefile.am'ized, (but installs nothing) made distclean target slightly more clean -- check it by hand first, please --- also you'll want to remove vq/Makefile if the ...am passes inspection ------------------------------------------------- diff

Hi, Does anyone have an idea about the possibility to apply psychoacoustic models as the ones in mp3 or AAC to a CELP coder? Thanks! /Pontus <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 'speex-dev-request@xiph.org' containing only the word 'unsubscribe' in the