Hello Hoegen, the main idea is to implement HRTF (http://en.wikipedia.org/wiki/Head-related_transfer_function) in the conference mixer. That requires to send a stereo signal back to the clients. As regular cleints do not have more than one microphone, sending stereo to the server is not necessary, but if this is easier, why not. HRTF is the main idea and part and there is a non sip (but proprietary) solution which already implements this eidea and it is amazing how good you can hear different people. So that's the practical idea.
My question is, if I can implement this using sipXecs. Freeswitch is a possibility but it seems that the project is that big, that it is very difficult to change and adapt things. Which codec is used is a second question, but I do not care at the moment. L16 seems to be mono and stereo, so the implementation of L16 does not need to say anything about stereo. To shorten it up: FreeSWITCH could be made progressing stereo but this is a extreme big project - too big for my bachelor thesis so I'm searching for alternative software. Thanks MatzeMuc86 -----Ursprüngliche Nachricht----- Von: Joegen Baclor [mailto:[email protected]] Gesendet: Freitag, 25. Februar 2011 02:48 An: [email protected]; sipXecs developer discussions Betreff: Re: [sipx-dev] Sip stereo B2BUA conference server On Friday, 25 February, 2011 05:20 AM, MatzeMuc86 wrote: > Hello, > > I try to develop a stereo back to back "user" agent conference server > where simultaneously not only mono but also stereo clients can > connect. B2BUA to be as much standard conform as possible (it's just > an idea). Stereo clients means that the client sends mono to the > server but gets a stereo signal back (upmixed by some tricks; see HRTF). > > As I already tried to develop this idea at freeswitch which seems not > be be possible, I want to know from some sipfoundry expters if this is > possible with the effort of a Bachelor Thesis (I want to program my > own, of course). > > Thansk a lot > MatzeMuc86 Mono going back Stereo? Would that be equal to saying a clients sends G.711 and the conference sends back L16 Stereo? This basically means that your client can decode L16 which begs the question why would it then send G.711 if it supports L16? I am not an expert in freeswitch but I think i've read somewhere that it supports the L16 codec. I also do not see the practicality of your thesis if that it is a hack. Talk to your thesis advisor and ask again what the real intention is and its merits in the real world. The only way to go stereo is to support a stereo codec sampling from a stereo capable device. _______________________________________________ sipx-dev mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipx-dev/
