Date: Thu, 26 Mar 1998 15:25:07 +0100 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Martin Husemann <martin@rumolt.teuto.de> Cc: etonumo@eto.ericsson.se (Ulltveit-Moe Nils), simons@rhein.de, freebsd-isdn@FreeBSD.ORG Subject: Re: Fax Message-ID: <1156.890922307@critter.freebsd.dk> In-Reply-To: Your message of "Thu, 26 Mar 1998 09:26:51 %2B0100." <199803260826.JAA05450@rumolt.teuto.de>
next in thread | previous in thread | raw e-mail | index | archive | help
In message <199803260826.JAA05450@rumolt.teuto.de>, Martin Husemann writes: >> This is probably not implemented. > >No, it is not implemented. > >> Implementing G3 fax in ISDN would mean simulating an analog modem >> on the digital link. This means having to generate the right waveforms >> for the modulated data, and receive analog data from the other end >> which you had to run FFT analysis on and then interpret. > >Probably not an FFT, a simple IIR filter might do (but I'm not good >enough in signal proccessing to be sure) You have it easy, the signal is already digitized for you, but it is way harder than this, you need to phasedetect it. -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." "Drink MONO-tonic, it goes down but it will NEVER come back up!" To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isdn" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1156.890922307>