[op25-dev] Audio Dies Pt2 and JSON meta tags????

op25 at zellners.com op25 at zellners.com
Mon Feb 25 00:34:14 UTC 2019

Quoting Graham Norbury <gnorbury at bondcar.com>:

> This is not a unique problem especially with RPi3 and aloop/darkice.  My
> recommended solution is to switch over to liquidsoap which avoids alsa and
> aloop altogether.  Instructions can be found in the README-rpi3-liquidsoap
> file in the top level op25 directory.

First, MY PI3 op25 is humming along with darkice and audio quite  
fine... its only issue is when metatag updates fail causing a crash..  
thats fixed in a later version, but I can't update that part right  
now.. listening to it right now after days and days of running....

Second, LAPTOP setup is the issue.....

Thrid, I planned to do a different test today, but a hardware snafu  
nixed that, till later..

Fourth... I have had the laptop taking audio from VLC output to loop0  
and its been playing for hours...this is continous audio... I just  
took my mp3 NAS and dumped it into VLC! :)

Fifth, I do NOT LIKE liquidsoap. I have my reasons, mainly I KNOW  
DARKICE, and use it extensively for years.

So with audio flowing non stop locally on the laptop

And audio flowing from a VLC Playlist out aloop0

op25 seems to be the issue...'

Now the the only difference in this is a CHANGE IN SYSTEMS from a  
local about 3 air miles to a new system coming online, tower is 12 air  
miles away... I was using op25 to monitor another part of this system  
that was about 20 air miless away....

The signal is about ~30-31db for each channel, CC or traffic, and  
audio is clean and crisp.. when I let it only play on local .... I was  
using the same laptop for the local system and feeding it out  
darkice/aloop....I just was not monitoring it close to see if it was  
dying and was futzing with what it was monitoring etc.. so I can't  
100% verify that it was pumping out audio 24/7 on that system...

So one thing could be signal strength, but that should only matter in  
the recovery of the CC and audio. Constellation looks good, eye  
pattern looks good... steady stream of CC data, even dealing with the  
rotations.. Harris system.... they have taken their rolling CC from  
EDACS and added it to their P25 CAI, more so than just normal.. which  
when monitoring the part of this system system 20 miles away, I saw CC  
decode issues, missing audio... to be expected.. the system is setup  
so as not to cover me from that site(s)... its a dual zone setup  
similar to their existing system... not really sure why keep this in  
P25.. but considering the vendor is the same, it doesn't surprise me....

I probably will take and revert this back to the local system  
overnight to see if audio comes out of this thing 24/7 and then  
proceed from there...

I will most likely try my Pi3 setup with this system when I can set it  
up... and then see if it works... with dakrice/aloop...

What I am after is getting way to pinpoint where the issue is.. op25,  
aloop, what ever... Some may have an affinity for liquidsoap, just as  
I have affinity for darkice.. I use ALSA plugins to act as sort of  
split to take a single stereo input and send out 2 feeds with out  
issues..24/7/365 for over 10 years. And like I Said I am listening to  
the PI3B with darkice/aloop feed out out audio right now.. just a  
different system.... which I am hoping is not the culprit... Motorola  
v. Harris?, signal... (Note: I use commercial antennas and LMR cable,  
the antenna for these systems is 25 feet in the air above local scrub  
and I actually will put a yagi onto this in the final setup... its on  
the omni right now

Ultimately this has to run on Pi3b+'s as my setup for op25... and I  
need to setup probably about 3-4 for this system once its full blown  
use.. so if I get things to work on the Pi3b+ as a test then I will  
just go with that... and chalk the laptop upto an anamoly... I would  
mostly use it for local audio any way..

The laptop was pushed into this due to the users in one group  
switching sooner than I was planning on them....

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