op25 on the Raspberry Pi 4

Joined
Jul 27, 2020
Messages
42
This morning I down loaded and install both versions of op25 on the Raspberry Pi 4.

With the official release of the the operating system (Raspbian, Raspberry Pi OS).

They both worked using pulse audio and they both failed using ALSA audio.

If you used the default "ALSA", it stutters along at slow speed.
If you -O ALSA, it generates the following error messages -

using ALSA sound system
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM ALSA
failed to open audio device: ALSA OP25 Listening on 127.0.0.1:23456
audio closing
python version detected: 2.7.16 (default, Apr 6 2019, 01:42:57)
[GCC 8.2.0]
Allocating 15 zero-copy buffers

With SDRplay version of Raspbian, It of course does just the opposite -

The ALSA works and the pulse audio fails.
 

boatbod

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Joined
Mar 3, 2007
Messages
2,570
Location
Talbot Co, MD
This morning I down loaded and install both versions of op25 on the Raspberry Pi 4.

With the official release of the the operating system (Raspbian, Raspberry Pi OS).

They both worked using pulse audio and they both failed using ALSA audio.

If you used the default "ALSA", it stutters along at slow speed.
If you -O ALSA, it generates the following error messages -

using ALSA sound system
ALSA lib pcm.c:2565:(snd_pcm_open_noupdate) Unknown PCM ALSA
failed to open audio device: ALSA OP25 Listening on 127.0.0.1:23456
audio closing
python version detected: 2.7.16 (default, Apr 6 2019, 01:42:57)
[GCC 8.2.0]
Allocating 15 zero-copy buffers

With SDRplay version of Raspbian, It of course does just the opposite -

The ALSA works and the pulse audio fails.
RPi4 is know to be a PITA with Pulse audio, but I guess if you're running a desktop (rather than headless) then it's a fair bet that Pulse is operational. "-O pulse" is probably the way to go. Note that "-O ALSA" is not a valid option unless you have defined 'ALSA' in your asound.conf
 
Joined
Jul 27, 2020
Messages
42
Oh well, I guess that it does not really matter. They seem to work with one or the other -

raspberrypi 4.19.75 - pulse audio works.
raspberrypi 5.4.51 - default audio works.
 

rlmurray56

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Joined
Oct 10, 2019
Messages
42
Location
Puyallup, WA
for what it's worth, I'm running OP25 with the -O pulse option on an RPi4 headless, without issues. No special configuration was necessary on my end and I run three instances of OP25 regularly.
 

boatbod

Member
Joined
Mar 3, 2007
Messages
2,570
Location
Talbot Co, MD
for what it's worth, I'm running OP25 with the -O pulse option on an RPi4 headless, without issues. No special configuration was necessary on my end and I run three instances of OP25 regularly.
Yeah this is weird. You'd kinda expect the same behavior with the same software but it doesn't seem to work out that way. Mine was a royal PITA to get Pulse working so I could run GQRX.
 
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