search for: soundfield

...should take a look at the Vorbis specification and the Vorbis Stereo modes HTML page. Thank you for Sebastien. I am new to compressed audio coding so please correct any stupid assumptions I make ... 8>D >From the Vorbis spec and Stereo mode page, my tentative recommendations as a (pseudo) Soundfield and Ambi guru are as follows. - The Ambisonic B-format WXYZ channels should be should be lossless coupled together over most of the frequency range. This will give the most gain as W "usually*" has everything that XYZ has. A perfect B-format signal has scaled versions of XYZ in W.* -...

...needs 5 channels for 2nd order, one channel less than 5.1! Using the extra channel adds FOA vertical information, for a much better experience than plain 5.1. I would suggest to also include support for the UHJ format, which is roughly equivalent to 3 channels FOA, but using only 2 channels; even soundfield rotation is possible with UHJ (although less good), enabling horizontal "VR audio" with only 2 channels. Ok, enough proselytism... VR+Ambisonics+Opus is a winning combination. -- Marc

...I don't know how this "WXYZ" data is setup, if XYZ are just other audio channels which can be handled the same way or if they need to be treated special.. Big question I have is: Is it patent-clear? Trademark-clear? There is a patent by Michael Gerzon on the tetrahedral array (soundfield) microphone, but which software patents exist for the system itself needs to be investigated further. -- The recognition of individual possibility, to allow each to be what she and he can be, rests inherently upon the availability of knowledge; The perpetuation of ignorance is the beginning...

...e simple 4.0 5.0 .. 7.0 Speaker Decodes do deal with older 'dumb' players. b) stereo support. >simulated blumlein are the simplest downmixes and could be added with a very minimal amount of code. They are also the least satisfactory. As most of the prize winning recordings made with Soundfield mikes have used them in plain stereo mode, usually Blumlein (eg the Chesky's) I don't think we should look down on simple Blumlein. The 3 good stereo downmixes are - Blumlein fig-8s at 90. Probably best for loudspeaker stereo - Back to Back cardioids. This is best for simple binauaral....

...Ambisonics for irregular arrays can be an > art form, it's not like working with common surround formats. Thanks for the input. I agree. > I would suggest to also include support for the UHJ format, which is > roughly equivalent to 3 channels FOA, but using only 2 channels; even > soundfield rotation is possible with UHJ (although less good), enabling > horizontal "VR audio" with only 2 channels. UHJ is an interesting way to preserve compatibility with non-ambisonic playback systems. However, I have not seen it generalized to higher orders. I expect that its popularity wi...

I threw a rough draft of an alternative format incorporating the comments received so far in this discussion on the wiki: http://wiki.xiph.org/index.php/OggPCM#Format Oliver, This seems to me like it would support the ambisonic requirements you mention, though it doesn't (and I imagine won't) describe the mic locations. Somebody who actually uses that info could probably define extra

i didn't find anything about tagging flac files as surround files. i think there should some possibility to tell the player how to play a multi-channel file (how to map the different channels to the speakers or if there some decode is needed, like for ambisonic files). any idea how to implement it?

Michael Grave just posted a question about surround conferences. http://www.facebook.com/notes.php?id=564633430#/note.php?note_id=5009726 3908&id=564633430&index=0 I didn't see it posted on the ast-list, what do you think? Does something like this have potential? I'd love to listen in on one of these calls to see how it actually sounds if someone builds a trial

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

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

...E-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Hi, Rob Fletcher forwarded this to me as one of the researchers most involved in Ambisonics currently. I am, at this moment, developing a set of new subcommands for the Snack audio extension to Tcl/Tk which handle Ambisonic panning, soundfield manipulation, decoding and mixing. The panning one is almost finished and the others should follow soon after. It has proved unbelievable easy to write new stuff for this package - less than two weeks from starting to look at how to do it to having most functions working (and that's despite doi...

>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

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?

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