Thanks Markus for your explanation. This is more that I can understand...
I understand the distinction between this format and a multi-channel format (like for ambisonic). But I can't keep myself from asking a (hopefully) simpler question: Is the standard also for multi-channel description and/or rendering of the acoustics of audio scenes, not only for binaural? Or: Is the focus on binaural a first step? -- Marc On Mon, 16 Mar 2015 02:00:43 +0100, Markus Noisternig wrote: > Dear Marc, > > Spatial acoustic data is typically described by spatial acoustic > transfer functions. AES69 describes a format for storing spatial > acoustic data with a focus on interchangeability and extensibility > and provides a basis for a wider generalized interchange of > space-related audio data. It allows to store, e.g., room impulse > responses measured with microphone arrays and loudspeaker arrays. > > AES69/SOFA is thus not limited to HRTF/HRIR data. There is no > preference on binaural listening, but it all started from a > discussion on sharing HRTF data in between research labs. > > > What is the difference between AES69 and SOFA: > > AES69 builds upon SOFA. It consists of “general specifications” and > “conventions”. Conventions define recommendations on the naming of > AES69 attributes, variables, and dimensions for discipline-specific > data structures, that is particular measurement setups. In other > standards a set of “conventions" is often referred to as a “profile”. > New conventions are discussed on the SOFA website. When a new > convention is considered to be stable enough, it will be added to the > AES69 standard through the normal revision process. > > The current version of AES69 standardizes > — The frequency domain representation of head-related transfer > functions (HRTFs); — The time domain representation of HRTFs, that is > head-related impulse responses (HRIRs); and — The time domain > representation of HRTFs measured in reverberant spaces, that is > binaural room impulse responses (BRIRs). > > We hope that we soon can add the following conventions to the > standard: — The Quadrature Mirror Filter (QMF) domain representation > of free-field HRTFs, that is the set of QMF parameters; or, even more > generally, — The time domain representation of spatiotemporal room > impulse responses, that is directional room impulse responses > (DRIRs); and — The modal representation of the 3-D wave field, that > is the spherical harmonics coefficients of the incoming/outgoing wave > field. > > In our research lab, we are currently using an alpha version of a > SOFA convention for storing MIMO room impulse responses that were > measured with a 32-channel spherical loudspeaker array and a > 64-channel spherical microphone array. These data can be then > represented in various formats, such as the room impulse responses > for each transmission channel (i.e. the transfer paths between each > loudspeaker and each microphone) or the spherical harmonics > coefficients of emitted and received wave fields, respectively. > > Please note that AES69 is a “spatial acoustic” and not a “spatial > audio” format. You could of course use AES69/SOFA to store > multichannel audio data, but I would recommend using more convenient > multichannel audio data file formats such us broadcast WAV. > > I hope that this answers your questions? > > Kind regards, > > Markus > > > > > > On 16 mars 2015, at 00:16, Marc Lavallée <m...@hacklava.net> wrote: > > > > Hi Mr. Noisternig. > > > > At first glance, this data file format is about binaural measurement > > and rendering, and not about multi-channel based auditory scene > > representation. I don't have access to the AES library, but the SOFA > > specs are freely available, and I suppose the standard is based on > > the specs. > > > > Even as a hobbyist, I can understand its usefulness, but why is it > > named "spatial acoustic", without a reference to binaural > > listening? It is for marketing reasons, based on the predominance > > of headphone listening? > > > > -- > > Marc > > > > On Sun, 15 Mar 2015 16:13:47 +0100, Markus Noisternig wrote: > >> Dear Sursounders, > >> > >> We are pleased to announce the recent publication of the AES69-2015 > >> standard for file exchange - Spatial acoustic data file format. See > >> also the AES press release at http://www.aes.org/press/?ID=293 > >> <http://www.aes.org/press/?ID=293> > >> > >> The new AES69-2015 standard defines a file format to exchange > >> space-related acoustic data in various forms. These include HRTF, > >> as well as directional room impulse responses (DRIR). The format is > >> designed to be scalable to match the available rendering process > >> and to be sufficiently flexible to include source materials from > >> different databases. > >> > >> This project was developed in AES Standards Working Group SC-02-08 > >> and standardizes the Spatially-oriented format for acoustics > >> (SOFA), which aims at storing and transmitting any > >> transfer-function data measured with microphone arrays and > >> loudspeaker arrays. See http://www.sofaconventions.org/ > >> <http://www.sofaconventions.org/> for further information and > >> ongoing format discussions. > >> > >> Open source application-programming interfaces (API) for Matlab, > >> Octave, and C++ are available online at > >> http://sourceforge.net/projects/sofacoustics/ > >> <http://sourceforge.net/projects/sofacoustics/> > >> > >> All the best, > >> > >> Markus and Piotr > >> > >> > >> -- > >> Markus Noisternig > >> Acoustics and Cognition Research Group > >> IRCAM, CNRS, Sorbonne Universities, UPMC > >> Paris, France > >> > >> Piotr Majdak > >> Psychoacoustics and Experimental Audiology > >> Acoustics Research Institute > >> Austrian Academy of Sciences > >> Vienna, Austria > >> -------------- next part -------------- > >> An HTML attachment was scrubbed... > >> URL: > >> <https://mail.music.vt.edu/mailman/private/sursound/attachments/20150315/e3764123/attachment.html> > >> _______________________________________________ Sursound mailing > >> list Sursound@music.vt.edu > >> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe > >> here, edit account or options, view archives and so on. > > > > > _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
