similar to: Conformance (was Re: Why is Vorbis development slow?)

Reinventing the wheel is fun. I've just got working a (sort of) complete implementation of vorbis using (very nearly) only the documentation. This was quite easy overall as the documentation is very comprehensive and clear. Nice job, whoever put it together! The one spot I had some trouble with was the low level residue decode. The pseudo code at

Hi everybody: Here is this week's Ogg Traffic with all new updates on recent activities in the world of Xiph.org. The HTML version is up at http://www.vorbis.com/ot/20030415.html. Enjoy! -Carsten <p>Ogg Traffic for Tuesday, April 15, 2003 [1]Carsten "Purple" Haese April 15, 2003 _________________________________________________________________ Table of

Hi all, I'm porting the Tremor code to an ARM platform. Unfortunately, we didn't use the low mem branch code for CPU performance consideration, and now I find the memory use in it is huge for the embedded system. After looking into the code, I found the header parse, especially, the codebook unpack part takes a lot of memory. Tremor decodes the codebooks to a cache to store

Dear All, As i have understood it , the Huffman codebook uses a huffman code present in the bitstream ( lets us say it is decoding a floor 1 Y value using the specifed codebook number ) to walk through the huffman code book tree till it hits a leaf node which is nothing but the entry number. If we consider our floor 1 Y value example , this entry number is directly being used as the Y value.

libvorbis 1.3.6 has been released. This release fixes several vulnerabilities, including CVE-2018-5146, that could allow code execution from a specially crafted Ogg Vorbis file. * Fix CVE-2018-5146 - out-of-bounds write on codebook decoding. * Fix CVE-2017-14632 - free() on unitialized data * Fix CVE-2017-14633 - out-of-bounds read * Fix bitrate metadata parsing. * Fix out-of-bounds read in

libvorbis 1.3.6 has been released. This release fixes several vulnerabilities, including CVE-2018-5146, that could allow code execution from a specially crafted Ogg Vorbis file. * Fix CVE-2018-5146 - out-of-bounds write on codebook decoding. * Fix CVE-2017-14632 - free() on unitialized data * Fix CVE-2017-14633 - out-of-bounds read * Fix bitrate metadata parsing. * Fix out-of-bounds read in

Hi, While following the developer mailing list, I came across "tremor-lowmem" version. I did some search of it in Xiph.org and "tremor" source code but wasn't able to find it. I would like to know if there is any separate thread for the "tremor-lowmem" version as we are working on the fixed point implementation of Vorbis code and we are looking forward for

We've implemented a vorbis decoder based on Tremor and as part of the documentation we're also writing about psycho acoustic models and encoding. We're quite up to date with the decoding process and psycho acoustics in general but unfortunately not on the psycho acoustic encoding used in Vorbis. We have a few questions that would we would be very thankful to have answer to: Which

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:

As to tremor fixed-point implementation, i got several questions, and hopefully some one can help me out. Thanks a lot! 1. For DSP chips with small and limited memory, how much memory do we really need for saving all codebooks before we start to decode audio packets? Can the bit-rate give us some clues? Is there some simple guidelines for this? 2. For CRC error protection, it seems to me that

Hi all, Below is the Vorbis RTP Internet Draft as sent to the AVT working group of the IETF. Comments and feedback is still welcomed from the Vorbis community. Cheers Phil ---------------------------8<-----------------8<------------------------ Network Working Group Phil Kerr Internet-Draft The Ogg Vorbis January 07, 2003 Community / OpenDrama

Monty lost this one. :) ---------- Forwarded message ---------- Date: Fri, 21 Apr 2000 09:30:31 -0700 From: Monty <xiphmont@xiph.org> To: Gregory Maxwell <greg@linuxpower.cx> Subject: Re: Branch: residue codebook trainer. > > I was looking at the residue trainer in the branch, and I noticed: > > " /* seed the inputs to input points, but points on unit

Hi, Please brace yourselves for some possibly stupid questions. Why are there only 2 codebooks for floors and many more for residue values? What makes the encoding of floor values fundamentally different from encoding residue values? I have a basic understanding of VQ, and looking at the floor decode function, it all makes sense 1) Read the codebook index from the stream 2) Do a

The following has been committed to the Vorbis I spec as of r19445: Errata 20150226: Single entry codebooks A ?single-entry codebook? is a codebook with one active codeword entry. A single-entry codebook may be either a fully populated codebook with only one declared entry, or a sparse codebook with only one entry marked used. The Vorbis I spec provides no means to specify a codeword length of

Hi, From the vorbis decoder specification, it is clear that the decoder needs to have all the codebooks before decoding can actually begin. I will appreciate if someone can clear the following questions: 1. I guess the codebooks are derived from the actual input data. Probably the encoder may be making two passes through the input. The first pass finds out the frequency of different symbols

Hello, First off, please don't ask development questions directly from a single developer. I tend to answer emails only a few times a month. You will get much faster help by asking on IRC (#vorbis on freenode) or on the vorbis mailing list (vorbis at xiph.org or vorbis-dev at xiph.org). I am cc:inf vorbis-dev at xiph.org; please continue discussion there. > Initially i was not able to

Hello, Vorbis uses codebooks, for example to do vectorquantization and huffman-encoding. My question is - are all these codebook dynamicly generated ("trained") or are there also static codebooks used ? If yes, what specific tasks are these 2 types used for, during encoding ? Thanks Stoffke <p>--- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project

Monty Montgomery wrote: > Yes. Without the first three packets (which hold all the codec > settings and all the instruction how to handle the subsequent packets) > the rest of the stream is gibberish. Vorbis can't even unpack the > bits without the codebooks packed into the third header. Curiosity man here. Is there a finite set of predetermined codebooks or is the codebook

Hi, Am I correct in understanding that the codebooks are *not* adaptive during compression? I see that Packet #3 is written to the stream in the beginning of the encode process with no modification. If the codebooks are not adaptive, then why are codebooks included in the stream at all? Why not pass the mode type (A or B or C...) instead of all the mode info and let the decoder load it's

2009/6/18 Adam Rosi-Kessel <adam at rosi-kessel.org>: > On Thu, Jun 18, 2009 at 11:12:30PM +0900, Conrad Parker wrote: >> yow, that's pretty badly corrupted, the vorbis codebooks (usually the >> third packet) is completely gone. It looks like you'd need to throw >> away the first 16 packets, start with fresh headers, and copy in the >> rest of the data