Hi Richard,
Thank you so much for posting this observation (and to your colleague for making it). I built a vm with Ubuntu 10.04 64-bit, installed gnuradio via the build-gnuradio script, installed op25 using the basic quick install instructions on the wiki, and re-ran my flowgraph and IQ file and (drumroll, please) IT WORKS!
I get proper DUID identification and audio output.
Combined with the difficulty trying to route audio from gnuradio to dsd, and I can confidently say that is *not* one of the high points in my love/hate relationship with linux over the last 15 years...lol.
Finding the problem is way over my head, but I'd be happy to help to whatever extent I can. The tar file at this URL does provide an example of IQ baseband data that does work on 10.04 and does not work on my install of 11.10:
http://s3.amazonaws.com/public-xrp/p25.tar.bz2
Please note that I don't believe my install on 11.10 was done precisely the same way as above. It's certainly possible that there's something wrong with the build on my local machine.
Thanks!
--- In op25-dev@yahoogroups.com, Richard Clarke <richard@...> wrote:
A colleague of mine here has noted that op25 decoder seems to produce no audio when compiled and run on anything later than Ubuntu 11.04 for as yet undetermined reasons. Building and running on 11.10 or later (other mods required for 12.04) and you end up with the no audio problem. I've suggested that he post here with any more details he may have.
Cheers Richard
On 11 May 2012 03:50, rrgsti <bobrich@...> wrote:
**
Hi there,
AFAIK, the OP25 components do not show up in GRC. As you've found, gr-baz includes an OP25 block for GRC that encapsulates OP25 functionality. Balint also provided an example flowgraph that uses it, so you generally just need to tweak the frequency.
I'm having difficulty successfully decoding P25 with my RTL2832, so I'm very interested in your results. If you get no audio output whatsoever, take a look at the 'not quite' thread in here as well. I modified data_unit.cc to force all frames to be detected as LDU1 (voice), which is 100% broken, but I do get chunks of audio.
I also ran into the same issue with compilation. If you punch 'op25_imbe_frame.h' into the search function in this group you'll find a couple threads with fixes.
Last but not least, there is a discussion today on the rtlsdr subreddit about sampling rates. In short, ensure that your sampling rate is an even divisor of 28.8, such as 2.4 or 1.8msps, or you may get some artifacts in the signal.
Good luck!
--- In op25-dev@yahoogroups.com, "mungewell" <simon@> wrote:
Hi all, Just getting started with GnuRadio and RTL2832 so might be missing some
details, by following the instructions here:
http://op25.osmocom.org/wiki/wiki/BuildInstructionsPage
I was able (with a couple of hacks) to built OP25, IMBE and 4FSK -
however these did not appear as selectable blocks in GRC.
After some time I was able to figure out that they are missing 'xml'
definitions in '/usr/local/share/gnuradio/blocks'. Creating a quick/fake '4fsk.xml' made it/something appear.
So should these exist? Does anyone have examples of what they should
be....?
BTW the OP25 which did appear, seems to be from Baz install, not the
above instructions.
I also experienced problems with build against latest GnuRadio git
(seems that 'gruel_common.i' has moved) and the include files are not being installed... other than that things are 'peachy' :-)
-- libtool: compile: g++ -DHAVE_CONFIG_H -I. -I../.. -I/usr/local/include/gnuradio -I/usr/local/include -I/usr/include/python2.7 -I ../../../imbe_vocoder/src/lib -g -O2 -Wall -Woverloaded-virtual -pthread -MT _repeater_la-repeater.lo -MD -MP -MF .deps/_repeater_la-repeater.Tpo -c repeater.cc -fPIC -DPIC -o .libs/_repeater_la-repeater.o In file included from repeater.cc:3862:0: rs.h:8:29: fatal error: op25_imbe_frame.h: No such file or directory compilation terminated. make[4]: *** [_repeater_la-repeater.lo] Error 1 make[4]: Leaving directory `/home/simon/op25/repeater/src/lib' make[3]: *** [all] Error 2 make[3]: Leaving directory `/home/simon/op25/repeater/src/lib' make[2]: *** [all-recursive] Error 1 make[2]: Leaving directory `/home/simon/op25/repeater/src' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/home/simon/op25/repeater' make: *** [all] Error 2 simon@drifter:~/op25/repeater$ find .. -name 'op25_imbe_frame.h' ../blocks/src/lib/op25_imbe_frame.h simon@drifter:~/op25/repeater$ find /usr/local/include/ -name 'op25_imbe_frame.h' simon@drifter:~/op25/repeater$ --
Simon
-- *SCOTT ADAMS: Normal people believe that if it ain't broke, don't fix it. Engineers believe that if it ain't broke, it doesn't have enough features yet.*