Gqrx and DSD to decode MotoTRBO, P25, etc?

[David Ranch]

I'm thinking about tieing Gqrx with the RadioReference DSD - http://wiki.radioreference.com/index.php/Digital_Speech_Decoder_(software_package) together to decode say MotoTRBO, P25, maybe show Dstar data frames etc. I was curious if this is the right approach to go external for the decoding or not (I don't think there are any existing GnuRadio modules for this).  Would this be the right approach?  Ideally, it would be just a different set of modulation types under Gqrx for ease of use but I don't know if Gqrx can "pipe" say C4FM and other modulation types to external programs and take the audio back in to show it on the audio FFT, etc.

Thoughts?

--David

[Alexandru Csete]

Hi David,

I think it is the right approach to try using external demodulators
and decoders with gqrx. I neither have the time nor the interest to
maintain gqrx as a "one app does it all" package. For the moment, the
connection possibilities are limited to routing via the audio system
(pulseaudio or ALSA) and that works only out of gqrx. It is not
possible to get audio back into gqrx.

I plan to add a more generic data interface later, one that will allow
interacting with simple decoders via stdin and stdout.

Alex

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[David Ranch]

Hello Alex,

Ok, thanks for the feedback and hopefully I can get PulseAudio to play nicely with DSD but that software is somewhat abandoned due to what I imagine is legal pursuit from from some of the IP owners.  Beyond using DSD for some unique features (MotoTRBO, Dstar, etc), what about features that are already available in GnuRadio?  For example, P25 - http://op25.osmocom.org/ . Not knowing your software architecture, would it it be best to use GnuRadio code whenever possible and then go external when required?

--David