[op25-dev] Re: OP25 GRC - Almost but not quite working

Quick update from my end. It looks like every frame coming out of the fsk4 demodulator (I'm assuming, still a n00b here) is marked with a 'duid' of 0x0. Consequently, when data_unit.cc initializes a new data_unit from the frame, it is always creating it as an HDU (P25 header) type. This then prevents the IMBE decoder from being executed b/c it's not a voice data unit type (LDU1/LDU2 (no idea what these mean)). I figured maybe it has something to do with our system (Ohio MARCS) not being full P25 compliant and not including metadata of any sort, so I just made the following change to data_unit.cc and re-ran it: --- op25-orig/blocks/src/lib/data_unit.cc 2012-04-24 10:31:29.139694592 -0400 +++ op25/blocks/src/lib/data_unit.cc 2012-04-26 08:12:35.183962129 -0400 @@ -39,7 +39,8 @@ uint8_t duid = extract(frame_body, 60, 64); switch(duid) { case 0x0: - d = data_unit_sptr(new hdu(frame_body)); + //d = data_unit_sptr(new hdu(frame_body)); + d = data_unit_sptr(new ldu1(frame_body)); break; case 0x3: d = data_unit_sptr(new tdu(frame_body, false)); This seemed to sort of work as I now get rather garbled, but intelligible, audio from the decoder. I've uploaded the baseband capture (1Msps) and resulting audio .wav file that I get at the following URLS: http://s3.amazonaws.com/public-xrp/p25.iq.bz2 http://s3.amazonaws.com/public-xrp/p25.wav Not sure if this is of any use, but it is encouraging to hear voices at least. :) Thanks! Bob --- In op25-dev(a)yahoogroups.com, Andy Knitt <andyknitt@...> wrote: