Displaying 20 results from an estimated 7000 matches similar to: "State of the code 19991022"
1999 Aug 15
1
Vorbis transform description
OK, into the nitty-gritty, albeit a high-level version. If it sounds
like I'm glossing important details, you're right. This discusses
only the basic DSP; precise coding, framing, sync, etc, will be in
another mail.
Vorbis is a hybrid transform domain general purpose audio encoder,
like MPEG in some respects (it is rooted in much of the same basic
theory). For the most part, the
2003 Mar 14
0
encoder block diagram
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(Vorbis Illuminated seems a bit outdated,
2003 Mar 12
2
encoder block diagram
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
2006 Mar 27
2
Speex for sampling freq >48KHz
Hi,
I have one doubt again, that is Vorbis use DCT/MDCT based algorithm and also use psychoacoustic model so this is lossy codec. And I dont think it ca regenerate a better matching waveform than speex.
Then there comes FLAC which is the perfect answer to my question, I suppose. But my concern is this that FLAC use simple prediction algorithm and doesnt use any CELP based algo which could have
2006 Mar 27
0
Speex for sampling freq >48KHz
> I have one doubt again, that is Vorbis use DCT/MDCT based algorithm
> and also use psychoacoustic model so this is lossy codec.
Speex is also a lossy codec.
> And I dont think it ca regenerate a better matching waveform than
> speex.
At bit-rates above 32 kbps, Vorbis tends to produce better results than
Speex, even for speech. The only advantages of Speex over Vorbis at
these
2006 Mar 27
1
Speex for sampling freq >48KHz
Hi,
I chose speex initially because i had some work in VQ on speex i.e. modifying split VQ to GMM based parametric VQ and I thought If I train the GMM based VQ codebooks with audio signal and then do audio coding with speex, I probably get a better(smaller) residual signal even with speex. But I couldnt get that.
I was trying to get a lossless bitstream by MUXing the speex-bitstream and the
2004 Jun 02
4
Transient coding: AAC vs. Vorbis
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>>
2007 Dec 09
1
Experimental release of Ghost/CELT 0.0.1
Hi everyone,
I've just made the first public release of some new *experimental* codec
work I've been doing (part of the vague Ghost project) with help from
Monty and Timothy. This is mainly intended with developers with DSP
knowledge, not for doing anything useful with it (but it does encode and
decode already). Also, the main idea is *not* to replace either Speex or
Vorbis, but to code
2007 Dec 09
1
Experimental release of Ghost/CELT 0.0.1
Hi everyone,
I've just made the first public release of some new *experimental* codec
work I've been doing (part of the vague Ghost project) with help from
Monty and Timothy. This is mainly intended with developers with DSP
knowledge, not for doing anything useful with it (but it does encode and
decode already). Also, the main idea is *not* to replace either Speex or
Vorbis, but to code
2007 Dec 09
1
Experimental release of Ghost/CELT 0.0.1
Hi everyone,
I've just made the first public release of some new *experimental* codec
work I've been doing (part of the vague Ghost project) with help from
Monty and Timothy. This is mainly intended with developers with DSP
knowledge, not for doing anything useful with it (but it does encode and
decode already). Also, the main idea is *not* to replace either Speex or
Vorbis, but to code
2007 Dec 09
1
Experimental release of Ghost/CELT 0.0.1
Hi everyone,
I've just made the first public release of some new *experimental* codec
work I've been doing (part of the vague Ghost project) with help from
Monty and Timothy. This is mainly intended with developers with DSP
knowledge, not for doing anything useful with it (but it does encode and
decode already). Also, the main idea is *not* to replace either Speex or
Vorbis, but to code
2002 Nov 26
1
floor curve question (whitening filter)
<!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
2004 Mar 03
1
Matlab implementation
Hello!
I´m just interested if there exists a matlab implementation of the
vorbis encoder / decoder or at least of some parts of it (psychoacoustic model,
MDCT, VQ), would need it for my diploma thesis.
Thanks
Stefan Bayer
<p>--- >8 ----
List archives: http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
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1999 Nov 19
2
Impulses
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
2000 Nov 18
0
Problem linking libvorbisfile on Mac OS X
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
2009 Jan 14
0
[PATCH] Pitch now quantised at the band level, got rid of all the VQ code.
---
libcelt/Makefile.am | 6 +-
libcelt/bands.c | 26 +++++++++-
libcelt/bands.h | 2 +-
libcelt/celt.c | 23 +++-----
libcelt/pgain_table.h | 133 -------------------------------------------------
libcelt/quant_pitch.c | 117 -------------------------------------------
libcelt/quant_pitch.h | 44 ----------------
7 files changed, 37 insertions(+), 314
2000 Jan 07
0
VQ generation utilities ready + usage instructions
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:
1999 Nov 11
1
VQ codebook sanity check (please help)
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
2002 Jul 09
1
Vorbis Block Diagram
Hi,
I have looked through the documentation available from the downloads and the
web and haven't yet come across a block diagram which shows exactly how the
process of going from a .wav file to a .ogg file works. I suspect it is the
same as the mp3 process (with a different psychoacoustic model). I found
this document:
2015 Dec 04
1
A few questions about libvorbis from a newbie
Hello Martin,
> how a number of samples with no defined size is translated into 8, 16, or 32 bit values in my buffer
Although I do not know in detail about the actual implementation of libvorbis, most of the decoders should internally produce single-precision (32bit) floating point values, or 32bit integers as the result of PCM decoding.
They are downcast to PCM samples with 8bit, 16bit, or