similar to: Channel coupling in Vorbis

Hi, I need a psychoacoustics model for some experiments and would like to use the one included in vorbis. Is there any documentation about how to use it? Looks like the relevent code is in psy.c, but I can't go further. Also I would like to know whether I can be of any help in vorbis. I have some knowledge in speech coding (I doing my master at the University of Sherbrooke's speech

(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

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:

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

Richard Lee wrote: > But there is a caveat. Does Vorbis coupling preserve "phase" relations? Any references explaining this in simple detail? Sebastian : >"coupling" is a rather loose term in the sense that it doesn't exactly specify HOW it's done. It can be understood as the opposite of coding channels independently. Obviously there are many ways to do

>Yesterday I have finished writing the ambisonic pan filter for oggenc. May I ask what this "pan filter" is? I made some tentative suggestions for coupling Ambisonic B-format in a post "Vorbis Ambisonic coupling" on 4feb07 I gather from the last monthly meeting, that some of you, including Monty, had problems with the phase behaviour of B-format. Would anyone like a

It obviously would be nice to have such a mode available, for e.g. DVD audio compression. Apparently, the list doesn''t tell me too much about it. My questions are: 1. What is the current status of the 5.1 channel coupling in Vorbis? 2. If I''ll be interested in participation in its development, what is the recommended reading? -------------- next part -------------- An HTML

I'm a mathematician and programmer working on experimental surround sound techniques. Some of the ideas I'm working on require dozens of channels. These channels are often highly correlated and are very well suited to compression. I'm new to Vorbis. Does it attempt to address such issues? Thanks, --Richard --- >8 ---- List archives: http://www.xiph.org/archives/ Ogg project

Hi all, My apologies for the confusion ... but I am re-naming this thread again because the proposal doesn't come from Ambisonia. As the founder of Ambisonia I have only been 'mediating' between some members of the ambisonic community ... so it would be wrong to associate the spec with Ambisonia. To clarify. This is what the spec proposes: - that Mapping = 1 means the contents are

On 2/28/07, Ivo Emanuel Gon?alves <justivo@gmail.com> wrote: > On 2/28/07, Ralph Giles <giles@xiph.org> wrote: > > Well, there are todo pages at wiki.xiph.org, but I meant more in the > > community folklore sense. My point is a roadmap doesn't help much unless > > there are people committed to making things happen. That's been the > > problem with a

On 2/28/07, Ivo Emanuel Gon?alves <justivo@gmail.com> wrote: > On 2/28/07, Ralph Giles <giles@xiph.org> wrote: > > Well, there are todo pages at wiki.xiph.org, but I meant more in the > > community folklore sense. My point is a roadmap doesn't help much unless > > there are people committed to making things happen. That's been the > > problem with a

Hello all, Would somebody please comment on it? Thank you in advance. Monty wrote: Monty> "It depends". Vorbis will be able to do coupling such that Monty> joint stereo is exactly equivalent to L/R (reduction is in the Monty> range of 128->100 or so], or apply addiitonal stereo/spatial Monty> specific psychoacoustics to further reduce bitrate to eliminate Monty>

>I have been giving some thought to how to include Ambisonics in Ogg Vorbis. As I understand it, mapping type = 1 was meant from the start to indicate an Ambisonic stream. The only other information required is the number of channels which thanks to Mr Leese's clever trick tells us exactly which Ambisonic channels are used up to 3rd order. __________________ >The channel coupling

Where can I find the Header file or whatever which specifies the "Mapping" flag. In feb - apr 2007, there was a lot of discussion about Ambisonics and Monty kindly stated that Mapping = 1 ; Denotes and Ambisonic file as opposed to = 0 which is 1 speaker/ 1 channel Has this been written explicitly into the standard? Which standard should I be looking at?

Hi Opus list. I subscribed because your discussion on the IETF draft ("Ambisonics in an Ogg Opus Container") was mentioned on the sursound list. I tried Opus for ambisonics more than a year ago. It does works with uncoupled channels (I had to patch the encoder). I don't know what else could be done to optimize support for ambisonics, as I'm not a codec expert. So I think that

On Sat, 28 May 2016 16:21:33 -0700, Michael Graczyk <mgraczyk at google.com> wrote : > Hi Marc, Hi Micheal. > On Sat, May 28, 2016 at 10:44 AM, Marc Lavallée <marc at hacklava.net> > wrote: > > I subscribed because your discussion on the IETF draft ("Ambisonics > > in an Ogg Opus Container") was mentioned on the sursound list. > > Thanks for

Since the opusenc and opusinfo changes were independent I split them up and landed the opusinfo changes (with updated mapping family numbers). - Mark On Thu, Sep 6, 2018 at 4:22 AM, Mark Harris <mark.hsj at gmail.com> wrote: > Hi Drew, > > Sorry for the delay. > > FYI the patch that you attached is not your latest version. This > thread that you replied to is an older

Friendly ping for the opus-tools patch... ---------- Forwarded message --------- From: Drew Allen <bitllama at google.com> Date: Mon, Mar 19, 2018 at 2:53 PM Subject: Re: [PATCH] Support for Ambisonics To: opus at xiph.org <opus at xiph.org> On Mon, Mar 19, 2018 at 11:52 AM Drew Allen <bitllama at google.com> wrote: > Hello all, > > Sorry for the delay (got really

Hello all, I'm using the directshow filters by Tobias. Yes I know they are not supported here :) The vorbis encoder (I really mean encoder, not decoder) by tobias works good in 2 channels mode, but with 6 channels it exchanges the order of channels while encoding. The front center goes to the front right, and the like. I have reported the problem, but Tobias gives no signs of life. I want to

All, Progress has been made on the proposed draft spec for integrating ambisonics into vorbis. We are not yet finished (should be soon), but you can see the progress here: http://docs.google.com/Doc?id=df4dtw69_3626qqq6st The issue we have hit now concerns how/who would implement the encoding and decoding in Vorbis Tools. Because ambisonics uses spherical harmonic components, an ambisonic file