similar to: Vorbis transform description

I've made block diagram of the encoder because I tried to find out, how it works http://stoffke.freeshell.65535.net/ogg/block.html Although there are specifiation docs, that give very detailed information about single aspects of the encoding (or decoding) , I'm missing documenations that give a more general overview, about how the encoder works. (Vorbis Illuminated seems a bit outdated,

I've made a block diagram of the encoder because I tried to find out, how it works http://stoffke.freeshell.65535.net/ogg/block.html Although there are specifiation docs, that give very detailed information about single aspects of the encoding (or decoding) , I'm missing documenations that give a more general overview, about how the encoder works. (Vorbis Illuminated seems a bit

Thread-split from the vorbis-mailing list ("Vorbis determined to be as good as MPC at 128 kbps!") <p>On Sun, 30 May 2004, Segher Boessenkool wrote: [Steven So] SS>> If iTunes AAC can encode castanets with much less pre-echo at SS>> ABR 128 kbps, then hopefully there will be an imaginative SS>> (and non-patented) way of doing this in Vorbis without the SS>>

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

The VQ codebook generation utilities are more or less ready to go. Minor things are left to do, but those will have to be handled as I to them :-) The next thing to do is complete the interface to get compression modes and codebooks to the library for encoding (minor stuff), and then arrange how exactly the MDCT residue is filtered through the codebooks. VQ codebook util instructions:

Dear Stefan, In the paper "Improved Forward-Adaptive Prediction for MPEG-4 Audio Lossless Coding", a non-linear compander is applied to the parcor coefficients prior to quantization. This compander is designed in order to minimize quantization error, especially for magnitudes close to unity. If you determine the typical distribution of magnitudes of the LPC coefficients, you could

I'm working on getting the Darwin/Mac OS X port of Vorbis up and running again and have run into problems building libvorbisfile. I have installed the latest libtool (1.3.5) and modified it to handle Darwin/Mac OS X better (to create shared libraries, dylibs, that can be linked against other dylibs instead of creating bundles which cannot be used as input to the linker). But, when it tries

Hi! I've spent the last few nights digging into the Vorbis source and working to implement a vorbis_synthesis_pcmout_int() function that kicks out interleaved int16_t pcm data. I think its important to have this function available to make the job for people using the codec a little easier. This function abstracts out the conversion to int16_t and removes the extra overhead of moving the pcm

(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 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>

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

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

Hello folks, The codebook infrastructure for Vorbis is now well underway. This is it! The last piece needed for *real* bitstreams. To that end, I have a decent VQ codebook generator running. I was originally using some farily typical merge/split algorithms and then decided that the right way to do this was to model a VQ codebook as an m-dimensional set of bubbles (like a foam). I know there

So, it turns out (and another implementation actually explicitly mentions it) that LSP->LPC computation using the FIR algorithm is very sensitive to noise (iterative algorithm) and really really requires doubles [we're not kidding]. This was complicating things for folks pursuing fixed point implementations, and also was a potential source for bugs if FP optimizations got out of hand. This

I write a work over Vorbis. ? ?Now I have a few questions to the function. ? ?For what is the MDCT used? ? ?For what is the FFT used? ? ?How is the expiration with the encodieren? ?In the reference to the MDCT,FFT and the hearing model . ? ?Is there a volume fragmentation in Subband as MP3? ? ?If it is possible, the answers in the detail ?Thanks ? -------------- next

Hi Jean-Marc, Hi Jim, I have also seen some problems with the 1.1.8 release on the C55x. So far I have boiled down the issues to the following: 1) We need our own "fixed_xx.h" header file. I don't know why, and haven't had time to investigate, but there is a definite improvement when I use the attached fixed_c55x.h file which has turned all the maths into inline functions.

Hi Any help is appreciate! These days I studied ogg vorbis encoder with sample rate 44.1kbsp,and I thought the whole chart was as follows: 1. read the PCM data and store them in a buffer 2. do MDCT on those PCM data 3. do FFT on those PCM data 4. use both the FFT and MDCT coefficient to the psychoacustic modle and derive an maximum allowable noise curve, and during this curse ,do the

First my environment MinGW and MYSYS with gcc 3.4.2 under Windows XP pro. I configured and built libbogg with out a problem. I configured libvorbis and it finds libogg. When I type make it dies with: gcc -shared .libs/mdct.o .libs/smallft.o .libs/block.o .libs/envelope.o .libs/window.o .libs/lsp.o .libs/lpc.o .libs/analysis.o .libs/synthesis.o .libs/psy.o .libs/info.o .libs/floor1.o

Hi guys, I'm trying to compile vorbis-tools with libvorbis-aotuvb5. The problem is that installed libvorbis conflicts with myself-compiled libvorbis-aotuvb5, though I specified --with-vorbis-libraries and --with-vorbis-includes to the vorbis-tools configure: vorbis-tools-1.1.1# CFLAGS="-static" ./configure

I can successfully compile the libogg prebeta4 tarball, but when I try to compile libvorbis I get make[2]: Entering directory `/home/me/dl/libvorbis-1.0prebeta4/lib' /bin/sh ../libtool --mode=link gcc -O20 -ffast-math -mno-ieee-fp -D_REENTRANT -fsigned-char -DUSE_MEMORY_H -o libvorbis.la -rpath /usr/local/lib -version-info 0:1:1 mdct.lo smallft.lo block.lo envelope.lo window.lo lsp.lo