On Tue, Oct 17, 2017 at 2:34 PM, gnorbury@bondcar.com [op25-dev] <op25-dev@yahoogroups.com> wrote:

More command line options are needed: -O Loopback:0,0 -V -2 -U

Thanks, I must have missed that detail with the conversion to rx.py. I already have -2, but not -V and -U. This fixed it. I'm getting audio through the loopback now!

Make sure you see an entry in the log file that says "audio device: Loopback:0,0" or whatever alsa device you are using.

I don't see this line in the output. I also haven't specified a log file. Is there a default log path? Is this something I should expect to see in stdout or stderr?

In reality you're probably better off making sure op25 plays audio through the default device before you worry about getting it going through the loopback.

I tried that, but virt-manager isn't even passing the speaker test audio, so I think that's a lost cause. There is no physical sound output on this system.

As a secondary recommendation, the alsa buffering is considerably better in the version of sockaudio.py found in my github repo. I suggest you upgrade to that version as it has other fixes too.

It's unclear to me what sockaudio.py does and how I would use it with darkice. Is there an example of this somewhere? I tried your repo, but got an error, so I went back to max: tom@stream:~/op25/op25/gr-op25_repeater/apps$ git status HEAD detached at boatbod/master Untracked files: (use "git add <file>..." to include in what will be committed) ../../../build/ ss911_tacoma.tsv ss911_tgs.tsv nothing added to commit but untracked files present (use "git add" to track) tom@stream:~/op25/op25/gr-op25_repeater/apps$ ./rx.py --args rtl=0 -N LNA:42 -f 774081250 -S 1320000 -v 5 -2 -T ss911_tacoma.tsv linux; GNU C++ version 4.8.2; Boost_105400; UHD_003.005.005-0-unknown gr-osmosdr 0.1.1 (0.1.1) gnuradio 3.7.2.1 built-in source types: file osmosdr fcd rtl rtl_tcp uhd hackrf bladerf rfspace Using device #0 Realtek RTL2838UHIDIR SN: 00000001 Found Rafael Micro R820T tuner gain: name: LNA range: start 0 stop 0 step 0 setting gain LNA to 42 supported sample rates 250000-2560000 step 24000 Exact sample rate is: 1320000.047207 Hz set_center_freq: 774081250 Using Volk machine: sse4_2_64_orc Traceback (most recent call last): File "./rx.py", line 671, in <module> tb = p25_rx_block() File "./rx.py", line 220, in __init__ self.open_usrp() File "./rx.py", line 606, in open_usrp self.__set_rx_from_osmosdr() File "./rx.py", line 542, in __set_rx_from_osmosdr self.__build_graph(self.src, capture_rate) File "./rx.py", line 283, in __build_graph symbol_rate = self.symbol_rate) File "/home/tom/op25/op25/gr-op25_repeater/apps/p25_demodulator.py", line 173, in __init__ self.lpf = filter.fft_filter_ccf(decimation, lpf_coeffs) AttributeError: 'module' object has no attribute 'fft_filter_ccf' Tom

Addendum: the filter error is something I saw once before. For some unknown reason your version of gnuradio does not have the fft_filter_ccf() routine, so you are forced to use fir_filter_ccf() instead. Max's code uses the FIR version by default, but I'd changed mine to use FFT because it was much more cpu-efficient for the lightweight hardware such as Rasp PI 3. You can edit the p25_demodulator.py file, line 173 and change 'fft' to 'fir' and it should work on your system.

I just pushed a fix for the fft_filter_ccf() / fir_filter_ccf() error that a couple of people have experienced. Fundamentally I don't know why some gnuradio installations have both while others only have one, but the p25_demodulator code now falls back to fir if fft is not present. Anyone who wants the update will need to "git pull" to download the change.