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f4exb / dsdcc

Digital Speech Decoder (DSD) rewritten as a C++ library
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DSDCC only decoding data #6

Closed JGAustin closed 7 years ago

JGAustin commented 7 years ago

First off, THANK YOU for this!! It fills a much needed hole in the dsd world, decoding content without requiring special audio configuration. I've been getting back into Ham radio and exploring digital modes,. What I am trying to do is use an RTL dongle attached to a raspberry pi as a remote "scanner" on a low-bandwidth connection. For testing purposes I've been using a nearby DMR signalwith the following command: rtl_udp -f 451.075M -s 70k -r 48k -| dsdccx -fr -T 3 -U 0 -i - -o speech "speech" is a named pipe that is picked up by the software I am using to package the stream. I have tried using -T 1 and -T 2 as well; however my understanding is that -T 3 would look at both timeslots for voice. I have also tried it without -U 0 and with -x. I've tried looking through the code; however I am not familiar enough with the hardware/protocols to make any changes. I have heard voice a couple of times; however, I am primarily only seeing data packets. I have tried it on multiple frequencies and get the same behavior. I attached the debug output for reference. dsdcc.txt.

JGAustin commented 7 years ago

I just discovered the documentation of the files produced by -M, it appears that it can't determine what type of frame I am receiving, dsdcc-M1.txt

JGAustin commented 7 years ago

It seems there was an error between the keyboard and the chair, other tools also see these transmissions as data and not voice. It does not make sense to me that they would be data unless it is either encryption or some type of privacy setting.