Willie, On Sun, Nov 25, 2007 at 12:14:28PM +0000, Willie Fleming wrote: > http://wiki.flightgear.org/flightgear_wiki/index.php?title=Talk:FGCOM > > Ive kicked this off with a request for _simplex_ comms and a wee moan about > voice quality. > > I used squawkBox once a couple of years back - I cant honestly remeber how > the
Ok, but I see many things that should be solved at the same time. We should create a list og topics to be done and we should try to give them priorities and perhaps name who try to solve these topics. But where to place this list? FG-Wiki? My own Wiki? > voice quality sounded. Can anyoine enlighten me? How realistic does it sound? > The ATC chatter we have is pretty realistic - obviously recorded by someone > with a newish scanner somewhere near Heathrow EGLL - in terms of volume > quality and random spurious noises and clicks - note the variations in > perceived volume of the different calling stations. These aircraft however > are all commercial operations, the radios found in GA aircraft will in some > cases sound a bit rougher. I see the following realism problems: 1.) absence of random white noise 2.) the voice channels should be limited with a high cut (at 4 kHz) (or an band pass between 300 Hz and 4 KHz) 3.) as in real life there should be a mechanism for realising crosstalking (e.g. the sender with the maximum of output pushes other senders in the background) 4.) real com radios have an automatic noise limiter (squelch) which makes a little noise after releasing the PTT key. 5.) pilots have engine sounds in the background Here are my ideas: 1.) A daemon in the background ca radomly place short samples of white noise and/or athmospherical noise an used channels. The problem is that crosstalking cannot be recognized from such a daemon (see 4). 2.) Perhaps an EQ in the sound chain. The best place would be iaxclient. But also ALSA would be working - but this is not real protable. 3.) That's a real problem. If this should work something like a complete new conference module for asterisk must be developed __AND___ a mechanism (schedular) for the voice clients (perhaps a simple FIFO). Not as easy as it sounds... 4.) Why not sending a simple short noise sample after muting the mic? This could be placed inside iaxclient. 5.) Again: mixing engine sound inside the mic stream... perhaps also at iaxclient? What I see: Everything is more a sound/VoIP problem rather than a FG problem... > Please note -- Im used to hearing ATC chatter in the UK --probably a LOT > different in the rest of Europe and the US. I don't know how the ATC chatter > we have sounds to the rest of you guys both in terms of content and quality. I tried to follow some web ATC streams and I udnerstand nearly nothing - especially the pilots are very difficult to understand. :-) Regards, Holger -- ##### #### ## ## Holger Wirtz Phone : (+49 30) 884299-40 ## ## ## ### ## DFN-Verein Fax : (+49 30) 884299-70 ## ## #### ###### Stresemannstr. 78 E-Mail: [EMAIL PROTECTED] ## ## ## ## ### 10963 Berlin ##### ## ## ## GERMANY WWW : http://www.dfn.de GPG-Fingerprint: ABFA 1F51 DD8D 503C 85DC 0C51 E961 79E2 6685 9BCF ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Flightgear-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/flightgear-devel
