I started with "rtl_fm", piping to "lame" and then to "ezstream". That gave me one audio channel to send to the Icecast server. "rtl_fm" has another mode where you can give it multiple frequencies and it scans between them, still only one audio channel. http://kmkeen.com/rtl-demod-guide/
Correction from previous message: Now that I look at the sources, it looks like it was "rtl_fm.c" in the "rtl-sdr" package that had to be patched for the zero-samples-on-squelch rather than the method I'm using now. The patch allows the audio stream to continue when the "radio" gets squelched. Without it the stream keeps stopping and have to connect again with your audio client, which is untenable. What I'm doing now: Running RTLSDR-Airband against one RTL SDR, decoding 8 different FM frequencies all at once (or 8 AM frequencies, such as aircraft), creating 8 audio streams, and sending all 8 streams to Icecast concurrently. So you can have multiple users connected to Icecast listening to whichever frequencies they like. You should be able to do ALL of this including some limited number of users connected to Icecast with an Rpi 3. I hear only one frequency corresponding to the audio stream URL I select from the audio client on my phone/tablet/laptop, but other users can be listening to any of the channels at the same time, up to however many users Icecast and your server can handle. If you use an external service instead of Icecast locally and feed the 8 streams to that service, you can have an unlimited number of people listening at once. On Thu, Jan 19, 2017 at 10:04 AM, Dana Rawding <[email protected]> wrote: > I’m interested to hear more! I’ve been doing something similar using gqrx > and a RTL-SDR receiver to scan the frequencies I’m interested in. I pipe > it out to vlc with the following: > cvlc --demux=rawaud --rawaud-channels=1 --rawaud-samplerate=48000 > udp://@:7355 --sout '#standard{access=http,mux=ogg,dst=192.168.X.X:8888}’ > > It sounds like you have a much more elegant solution. If two frequencies > are active at once do you hear both? The way I do it works like a > traditional scanner but I think your method is more like an ACARS scanner > which listens to multiple frequencies at once. I’m also interested in how > you are able to do 8 freqs as the best I’ve been able to do is 4. Are your > frequencies are relatively close together? For instance using this method > I’m able to listen to multiple freqs from 130 to 132 but I can’t pick up > the channels in 136 because the sdr doesn’t have enough bandwidth. > > Dana > N1OFZ > > > > On Jan 19, 2017, at 11:43 AM, Curt Mills <[email protected]> wrote: > > > > So... Ken, N7IPB, and I redid the scheme and can now receive eight AM > -or- FM frequencies at once per RTL SDR receiver, using one piece of > software instead of a pipeline of commands. There are also free audio > servers where you can send these streams so you don't have to run your own > Icecast server either. > > _______________________________________________ > Xastir mailing list > [email protected] > http://xastir.org/mailman/listinfo/xastir > -- Curt, WE7U http://we7u.wetnet.net http://www.sarguydigital.com _______________________________________________ Xastir mailing list [email protected] http://xastir.org/mailman/listinfo/xastir
